View Full Version : Melling oil pump m55(a) dangerous design change


thrasher
10-15-2006, 05:34:05 PM
How many of you know about the casting change on the old M55series oil pumps?

For those of you that don't know ( I was in this group till about three weeks ago), read this http://forums.godragracing.com/viewtopic.php?t=36095&highlight=


Melling select performance oil pumps
http://data.melling.com/Select/small_block_chevy.php

Mike-78 Z-28
10-15-2006, 07:23:36 PM
Oh great.

IDLZRUF
10-15-2006, 07:33:04 PM
Dam it I sell at least 5 a month both melling and seal power and seal power uses some melling pumps

Lowend
10-15-2006, 08:03:44 PM
strange...

thrasher
10-15-2006, 08:19:44 PM
From what I gather it affected Melling M55, M55A, and the M55HV.
Even the Moroso blueprinted 2100 pumps have the change.

1981coupe400ci
10-16-2006, 12:16:37 AM
lucky me.. i think i have a couple of the older HV pumps laying around.. may hang onto them for a future build.

Ztoy
10-16-2006, 09:58:24 AM
Man if it isn't one thing, its something else.....:mad: Just hope the 55 HV I got a couple of years ago doesn't fit into that category. Too late to check numbers, its in and pumpin....

DirtyScotty
10-16-2006, 10:10:42 AM
I could be in some KahKah. My HV has been on the car for about 8 months. :rolleyes:

tomsti
10-16-2006, 03:05:39 PM
I didn't see when the change happened, is there a date they put this into production?

Ted
10-16-2006, 05:47:17 PM
What about the big block style pump for the small block?
http://data.melling.com/Select/partphotos/10990.jpg

Mike-78 Z-28
10-16-2006, 10:07:36 PM
You for sure don't want that if you like your cam gear.

Cardinal
10-17-2006, 12:43:33 AM
I am so incensed/angry/mad/ticked off by the thought that ANOTHER company has lowered their standards to put a critical part out in the field without testing that product that I emailed the following letter:

"For your own sake, I think it would be in your best interest to recall the "new and improved" M55 small block Chevy high performance pumps, or change the part number, and/or put a disclaimer on them that they can fail if used in a high performance motor.

Trust me, you're going to ruin your business if you don't. I belong to three different boards (Gen II Camaro, Gen 1 S10, and a Gen III Camaro) and all three have posts from members warning others about the JUNK Melling oil pumps being put out on the market. More than one member has had problems. One went back to his engine builder who checked all of the pumps on inventory and found all of them had the new thinner casting. Another ordered a Moroso unit and it had the thin casting.

I sincerely hope that this is not a trend with your company. We've seen too many companies like TRW automotive and IBM (PC's) go down the tubes because of mismanagement and reduction in quality and/or performance of their parts. Melling oil pumps have been the benchmark for a top quality product and I sincerely hope that this event is an anomaly and not a trend.

Old School
10-17-2006, 02:04:46 AM
So if getting one with a 5 digit part number, it's ok to use???

Smokin70SS
10-17-2006, 04:46:25 AM
Thats really sickening. Since the pumps weren't labeled "unsuitable for hi-performance use" someone should stick it to them legally and force a recall for the people currently using them.

So if getting one with a 5 digit part number, it's ok to use???

Thats what I believe and sure hope thats what everyone is saying in the post. I'm using a 10550 pump as recommended by Hamburger's.

rustbucket79
10-17-2006, 03:33:11 PM
We have several of those pumps, and interestingly enough some of the boxes are labeled as "new generation" and have a warning sheet in the box. They will break in a race engine, don't use them.

Cardinal
10-17-2006, 07:47:38 PM
Here's the reply that I got from Melling:

Cardinal,

Thank you for input ,we value our customers opinion.

Melling’s design of GM’s Small Block Chevy oil pump was updated in 2004, see attached bulletin. At that time changes were made to the standard volume, M-55 & M155, and the high volume, M-55HV & M155HV, pumps. The changes improved many aspects of the pumps as compared to the original GM pump. To respond to customers requests one of the areas that improved was the hot idle performance of the pump. Durability was improved by eliminating a possible failure mode as noted in the bulletin. Casting improvements allowed the wall thickness of the housing around the gears to be reduced to reduce weight. Additional support rips were added to the neck area on the high volume pump casting. For stock replacement applications the changes will only increase customer satisfaction with our products.

For performance applications Melling recommends an M-Select oil pump be used, especially in solid motor mount applications. Melling has available a full line of SB Chevy performance oil pumps. Not only does the M-Select line of SB Chevy performance pumps utilize the previous casting design but are available with design features to further increase performance and durability. In addition the M-Select pumps are CNC machined to exacting tolerances and surface finishes. The M-Select line was created to provide engine builders a cheap insurance policy to improve one of the most overlooked critical components in a performance engine build, the oil pump.

Melling is a world class designer and manufacturer of Original Equipment, Replacement, and Performance oil pumps. The changes implemented on the stock replacement GM SB oil pumps improved performance, durability, weight and cost. With the recent dramatic increases in raw material costs these changes have helped to reduce the cost increase that is passed onto our loyal customers.

I have attached the warning sheet (pdf) that is included in each Melling boxed oil pump. Some of our private labeled oil pump customers do not to have the warning sheet included in the packaging.

Thank You,

George Richmond

Tech.Mrg.

-----Original Message-----
From: Cardinal
Sent: Tuesday, October 17, 2006 12:37 AM
To: technical@melling.com
Subject: New FUBAR Melling HV M55 Pump


For your own sake, I think it would be in your best interest to recall the "new and improved" M55 small block Chevy high performance pumps, or change the part number, and/or put a disclaimer on them that they can fail if used in a high performance motor.

Trust me, you're going to ruin your business if you don't. I belong to three different boards (Gen II Camaro, Gen 1 S10, and a Gen III Camaro) and all three have posts from members warning others about the JUNK Melling oil pumps being put out on the market. More than one member has had problems. One went back to his engine builder who checked all of the pumps on inventory and found all of them had the new thinner casting. Another ordered a Moroso unit and it had the thin casting.

I sincerely hope that this is not a trend with your company. We've seen too many companies like TRW automotive and IBM (PC's) go down the tubes because of mismanagement and reduction in quality and/or performance of their parts. Melling oil pumps have been the benchmark for a top quality product and I sincerely hope that this event is an anomaly and not a trend.

Sincerely,

Cardinal

______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact the Melling IS&S Group
______________________________________________________________________




M-55 and M155 GM OIL PUMP IMPROVEMENTS FOR 2004

In 2004 Melling Engine Parts will be releasing updated versions of the M-55 and M155 oil pumps. The new M-55 and M155 will have a new look due to a new housing and cover casting. The housing will now have a drilled outlet hole much in the same manner as the original GM pump. As compared to the original GM design the outlet hole has been re-positioned to improve the alignment with the bearing cap to improve oil flow up to the main oil gallery.

The cover design has also experienced a change. The relief valve bore is now machined as a blind hole with a step near the end for the relief valve to seat against. Leakage around the relief valve will be greatly reduced since the valve seats on the end of the valve bore. This will help to improve low rpm performance. This change eliminates the need for the press-fit plug and possible failure mode concerning the press-fit on the plug.

The changes to the relief valve are minor. The end configuration has been changed to match the chamfer on the valve bore. A 90-degree edge has been added to help clean foreign material off the valve bore wall.

The groove pin has been changed from a 3/32” diameter tapered pin to a 1/8” diameter straight pin. This change is to increase the strength of the drill to reduce tool breakage. Pin orientation will no longer be an assembly issue by removing the taper from the pin.

“Quality in all we do”


Melling Engine Parts has an oil pump for almost every application. Whether you need a stock
replacement pump, or one of our M-Select Performance pumps, we build quality into every one.
Special attention to performance and durability has been given to all of the new line of M-Select
Performance oil pumps. Take a look at what the leading manufacturer of oil pumps can do for your
performance lubrication needs. All pumps are tested for pressure and volume and hand turned before being bagged and boxed. The informational charts on the following pages will assist you making the correct choice for the MSelct
oil pump that best suits your needs. In Melling’s continuous drive to improve the quality and customer satisfaction of our products a series of design changes were recently made to the body casting used to manufacture the M-55 and the M155 family of oil pumps. Melling supplies these pumps to the Original Equipment market, as well as the aftermarket. The major design change was a weight reduction in the body casting. The lightening of the casting as and the drilling of the outlet hole resulted in a change in the appearance of the Melling pump. Melling will continue to use the old casting design for the pumps manufactured for our M-Select performance line of products. We highly recommend all performance engine builders choose one of our M-Selct oil pumps.

M-55HV 10550
“Very Important”

Casting Changes to the Small Block Chevy Oil Pumps Location of weight reduction done per General Motors request

crazymanz28
10-17-2006, 08:52:57 PM
Wow... I was starting to get nervous for minute while reading. But lucky me starting buying up parts before even got the engine out of the car and to the machinist. Ran to file cabinent, found the reciept and think I'm in the clear... Purchased my M55 HV 9.13.2003 even though it didn't get to turn over untill this past winter.

engine
10-17-2006, 09:24:51 PM
what I still don't understand is why GM was responsible for the casting change. Does GM still use an m-55 pump in it's new engines?

Old School
10-17-2006, 09:37:55 PM
That is some awesome stuff Cardinal! To many of us bitch and complain, but don't do anything about it. Glad to know your the type that doesn't just complain.

Michael

Cardinal
10-18-2006, 01:30:37 AM
I like to get to the bottom of a problem. I'm anal about it. As a shift mechanic, I've chased down vendors (when engineers wouldn't) to find out WTF was going on with a bad part. Most times, any good vendors aren't aware that a problem exists and are more than willing to fix the problem.

TRW had problems with their products and didn't give a dam what was going on. I know as I had a water pump shft fail on my 79 Olds Custom Cruiser with a 350. Put the fan right through the radiator. Found the shaft had a defect in it (you could see a non-ferrous glob in it). Wrote and called TRW. Person I talked to there said tough. I never bought another TRW automotive part. Good thing Speed Pro bought them and cleaned house there.

RacerRick
10-18-2006, 03:53:00 PM
There is similar problems with the Ford pumps. My friends 351W just broke off the Melling pump at the same place. THe motor is less than a month old.

We compared it to the old Melling pump and its a much thinner casting.

spinmaster
11-29-2006, 10:26:31 AM
Guys check this out. I found this on another message board. Good info by the way.

http://www.jalopyjournal.com/forum/showthread.php?t=143630&highlight=melling

350camaro
11-29-2006, 11:45:41 AM
This pump thing is kind of sad, the only thing Melling is doing is giving themselves a bad reputation.

thrasher
11-29-2006, 10:46:36 PM
Don't forget Moroso.They are selling their blueprinted 22100 and 22135 SB oil pumps for 'Performance" use.They're the damn thin casting pumps.

Ztoy
11-30-2006, 05:43:18 AM
This pump thing is kind of sad, the only thing Melling is doing is giving themselves a bad reputation.

typical business ploy. Why make a product that will last for a lifetime? They lose all those sales down the road....

GearHead72
11-30-2006, 09:50:07 AM
I emailed them letting them know I was a little ticked off that I was going to have to swap my 55HV for a new one. Mine had no note in the box. I told them it had not yet broken, but wanted to be safe. Somewhere along the email trail they thought it had broken and told me to send my pump to them (freight collect) and they would send back an M select pump at no charge. Since mines not broke, not much I can do, but I thought I would let anyone who has had an issue to contact Melling directly.

What they are offering doesn't make up for the problem, but at least they are very aware of the mistake they made.

***update - I just checked my email and they said that even though I am replacing the pump just as a precaution, they will send me an M-select at no charge. I just need to send my old pump to them first.***

GearHead72
11-30-2006, 09:57:00 AM
Also make sure you email sales, not tech support.

78LT383
11-30-2006, 02:49:01 PM
Well, great.

Now I get to tear my oil pan off and go buy another oil pump. I guess I should be thankful that it's not in the car yet. Add to that the fact that a pump we used to get for $13 at Advance Auto we now have to pay $72 for at Summit.

thrasher
11-30-2006, 04:23:50 PM
Ok guy's I just found this by searching all the links on oil pumps I could find

From Rick Moroso

Ok, here is the deal on our pumps.

We have two cast pumps that use the M-Select heavy-duty castings. They are p/n 22138, and 22139. They are both meant for 8 1/4 inch deep pans. ALL our other cast pumps use Melling’s fairly new "lightened" casting.

We have been selling the "lightened" casting for approximately 8-9 months. We fortunately have not had any failures that we have been made aware of.

We are working with Melling now to come out with a Moroso branded pump that will replace all our "lightened" housing pumps with a better, stronger casting. That is in the works, but will not be done for a few months.

I am very sorry for the confusion. Doug got some bad info at first, and in the effort of trying to put everyone at ease, posted it before we caught the mistake. We are doing our best to get it all straightened out.

For street and MILD performance, I would have no worries running any of our pumps. For racing and hard-core apps, I would use our 22138 or 22139 pumps, or any of our billet pumps.

Thanks

Rick

spinmaster
11-30-2006, 07:39:30 PM
I have a Melling selcet pump on the way.

ric70ss
12-01-2006, 12:42:07 PM
man after read all these thread and links about these pumps i'm piss:mad: here i'm thinking mayb it was something i did wrong with my engine something i miss when build it.....just here in the pass couple of month i been noticing a drop at idle in oil press..how it got below 20psi at hot idle and i run a auto meter warming lite with a 18 psi sender and it's lit up more then once resently. i've parked my car until i can find the time to pull the engine and see what the hell is going on. Now i'm going to drop the pan and look at the oil pump see if thats the proablm hell it hasn't even been a year yet since i build that engine!(Jan 06)and it dyno so well. well guess i know what i'm doing this weekend.

ric70ss
12-01-2006, 09:09:04 PM
yep couldn't want so i drop the pan and yep the DAMN thing is cracked. not completely broke off so now i got see how bad my bearings r oh joy for me:mad:

raven46809
12-02-2006, 01:41:09 AM
Is there a way we can make this a sticky so everyone can know about this. I wouldnt had know about this unless I checked this section today.

thrasher
12-03-2006, 12:48:13 AM
yep couldn't want so i drop the pan and yep the DAMN thing is cracked. not completely broke off so now i got see how bad my bearings r oh joy for me:mad:

Sorry man.I have a couple questions for you.

What brand oil pump is cracked?
What is the part number?
Do you have a 4-5 manual transmission?
Do you run solid motor mounts?
Do you run slicks?
Can you give a discription of your vehicle, the engine, the drivetrain, and how you drive it for us?
Can you post any pictures of it when you get it off so we can see where it's cracked?

circle racer
12-04-2006, 12:38:24 AM
I found out that they changed the pump when i called the factory to get the low pressure spring to put in the high vol pump and they told me not to use it in my race car that i should buy a different pump that cost about $50 more the new mildon oil pump (pn 18750)high volume and (pn 18755) standard volume look alot like the old style melling pumps I have yet to buy one I only saw the pic in dec 06 issue of circle track mag.

circle racer
12-04-2006, 12:39:21 AM
that should have been milodon www.milodon.com

ric70ss
12-04-2006, 05:16:39 PM
Sorry man.I have a couple questions for you.

What brand oil pump is cracked?
What is the part number?
Do you have a 4-5 manual transmission?
Do you run solid motor mounts?
Do you run slicks?
Can you give a discription of your vehicle, the engine, the drivetrain, and how you drive it for us?
Can you post any pictures of it when you get it off so we can see where it's cracked?


well spent all week end pull the engine apart be side the pump i found some other stuff witch i thing could of added to the problem. but to answer u it's a melling 55hv, yes i have soild engine mounts the car is a street car but seen more time at the track with 10.5 slicks. and on the street with 295/50's the engine has almost 8,000 mile on it, just shy of it all the bearing r in the copper or pass.the good side is i didn't through a rod thx god. the oil pump went back to the autoparts store and there taking care of that for me and the block and rods went to the machine shop.
so i'm rethinking what i want to do with the car and i'm thinking this time going the G machine route and getting away from the automatic...but well see.

thrasher
12-06-2006, 03:08:50 PM
How much HP. do you estimate the engine to have?
What RPM do you launch at?
What are your ET's?

Rick WI
12-07-2006, 04:20:11 PM
Given this is a sticky I'd like to provide a bit of feedback on our experiences with the Melling M55A pump.

No failures in street or race applications since the design change. Has always been a bullet proof pump for us.

Feedback on the new style pump.

I ran this pump when it FIRST came out on my engine.
Pickup cracked and broke off twice. First time lost the bearings in the bottom end. Second time got lucky.

I'll be down at PRI this coming week and will be anxious to talk to the Melling and Moroso folks on this subject to see what the real background information and impact of this "DANGEROUS" design is. In that type of venue you gather much more realistic and accurate information than you'd otherwise find via internet/email.

Good bad or indifferent I'll try to gather what I can.

ric70ss
12-10-2006, 02:01:18 PM
How much HP. do you estimate the engine to have?
What RPM do you launch at?
What are your ET's?


car ran high 12's with a 2500 stall shift at6500 dyno at the rear wheels 389.7 and 447.3 tq. i got the block and rods from the machine shop.looks good but putting it on the back burner for now got some other stuff i got to finsh.my son graduate high school this year and i got to finsh his car.and i got mywife a 77 Trans Am i want to have finsh by her birthday so it will b this summer b4 i get back to my camaro. :bowtie:

Rick WI
12-19-2006, 12:07:22 AM
Discussed this issue with Melling at length.

Here are the highlights for what it's worth. Hopefully some will find it useful.

1) The redesign was tested by both Melling and GM for fatique prior to release with no reliability issues.
2) Since being redesigned over 2,000,000 pumps have been shipped and sold.
3) Melling knows of 12 failures on these pumps following this redesign. One or two of them may be of the older design as they were never returned and conversations seemed suspect due to the estimated install date of the pump.
4) Applications under which the pumps failed have been soup to nuts, many appeared to be pretty hard core applications.
5) Melling is redesigning the pump not due to a statistically valid design issue but for customer service. This is currently underway.

The folks in the Melling booth were some of the best company reps we talked with all weekend. Top shelf company and the source for the best information on what will work for your particular application.

jester1
12-20-2006, 09:09:03 AM
Dame F@#k#n engineers!!!

78LT383
12-20-2006, 09:39:05 AM
Don't be so quick to blame the engineers, no engineer likes to make thinks weaker. Blame the short-sighted bean counters, accountants, marketers, and managers. Engineers are asked to do the dumbest things sometimes.

Dilbert is a documentary, not a comic strip!

TRQJNKY
12-20-2006, 01:53:34 PM
ok, the only thing i dont understand is this. why do they need to go back and redesign a bunch of oil pumps for the high performance stuff? why cant they jsut keep selling the old m55 pumps that worked fine???

78LT383
12-20-2006, 03:58:51 PM
I'm with you Dan. I'd love to kick the snot out of whoever's dumb idea this was.

Besides, other than crate engines, there aren't any OEM uses for these things anymore, so I'm struggling to figure out how this could ever be a cost reduction. Since the "select" pumps are still using the old tooling, they had to design and make the new tooling, run extensive tests to qualify the new design, etc etc etc. I don't see how it's a benefit to anyone except maybe to downgrade the standard product so that they can rape us when we realize we now have to pay $60 to get a pump we used to get for $15-20.

Rick WI
12-25-2006, 12:22:48 AM
Look at almost everything being made today. It's all "less" in some ways than it was before. All in the interests of controlling cost. With the cost of scrap iron and raw pig iron through the roof most all manufacturing processes have been changed in some way to reduce cost.

1981z28owner
12-27-2006, 10:58:49 PM
what are the signs of a pump just starting to crack?

kilo738028
01-03-2007, 08:13:26 PM
Here's a pic of my old M55 pump from my 80 Camaro, and the new one I got last year.

Mathes79Z
01-07-2007, 04:23:51 PM
yay, im not paranoid enough :) mines been in there since 2001 , a melling M55HV
ah well, an excuse to go 383 :)
per budget permits. nay..

1981z28owner
01-07-2007, 04:28:18 PM
if you put in before jan 04. you are ok. the change was not until about jan 04.

HOGDADDY
01-07-2007, 05:11:23 PM
What about GM crate motors. more specifically one that is about 2 years old?

rustover
01-20-2007, 07:12:17 PM
I am in the process of building a 383. I have the moroso 22135 waiting to be installed. It has the factory welded pickup for a 8-1/4 deep pan. After searching the web on this problem I'm afraid to use it. It looks like Moroso has the new replacement 22138. Has anybody ever used it? Also would it work ok in a 400hp 383 that will be driven on the street.

http://www.jegs.com/webapp/wcs/stores/servlet/ProductDisplayPopup?storeId=10001&catalogId=10002&productId=751389&itemId=623484&langId=-1&showValue=2&JegsPopup=ProductDisplayPopup

I know it will be overkill, but I think the peace of mind would be worth it. What do you think?

78LT383
01-20-2007, 10:33:50 PM
I think the high volume pump is a mistake on this kind of engine, but it should be a good pump otherwise.

rustover
01-20-2007, 11:18:33 PM
I think the high volume pump is a mistake on this kind of engine, but it should be a good pump otherwise.

78, please explain why. I have struggled with this decision. I do have the moroso 20191 pan. I mainly want the older style oil pump casting.

78LT383
01-20-2007, 11:54:21 PM
Stock volume is plenty for a SB chevy unless you're running high speeds for extended periods. With careful control of bearing tolerances, the SBC will end up just throwing all the extra volume through the pump relief valve, which does nothing but ever so slightly waste power and heat up the oil.

Elevated pressures similarly don't do the bearings any favors at street RPM levels. The extra pressure does increase the flow rate across the bearings, but that doesn't reduce bearing wear. If you are going to drill extra holes for oil cooling your pistons and such, the extra volume might be helpful, but this is way beyond street modifications. The extra pressure and volume just doesn't do anything beneficial in a street or mild street/strip application.

spoonLT1355
02-22-2007, 07:31:48 PM
Here is a copy of the warning that is in the box.
The box for the pump that WAS going to get put on the new engine this week-end.

http://i23.photobucket.com/albums/b355/spoonlt1355/S3010016.jpg

I guess I'll be getting another pump. :whine:

REARSPROCKET
05-08-2007, 01:34:24 PM
The 10553 is the heavy body standard volume pump to buy to equal the old M55A. Melling is going to correct the part number issue meaning sometime this year the M55A will be returned to its former glory and the weaker stock body will have a differnt part #, but when it will be corrected this year is not clear yet. This is what came from the horse's mouth Melling. I know to me the extra cash for this pump is well worth the piece of mind to protect all my hard work and investment. So for now buy the 10553.:bowtie:

jteu2002
05-11-2007, 06:34:49 AM
after checking my oil pump yes it is a HV 55

i orded an other one the performance one with 10% more volume and thick body
15522

after removing my distributor i got extencive damage onthe gear
and even on the cam that is now forthe trash bin

i got a new one to go in but do i need to make the crane mod if i use the 10% HV pump
anybody dit thise mod (picture)

frome the crane site:

More is not always better

If you've experienced excessive wear of a camshaft distributor drive gear, and maybe had to replace either the cam or the distributor drive gear itself, here's some good information you'll want to retain. Crane Cams roller tappet camshafts are ground on 8620 billet steel cam cores that are heat treat hardened to resist wear.

This 8620 steel billet material is wonderfully tough stuff, but it can also be very hard on distributor gears! To remedy this, Crane 8620 steel billet cams MUST use a high silicon copper alloy distributor gear, to prevent rapid wear of the camshaft's distributor drive gear. These are usually referred to as "bronze" gears.

Cast iron hydraulic or mechanical tappet cams are also susceptible to premature wear of the camshaft distributor drive gear or the distributor gear itself. This problem, when it occurs, is usually accompanied by the use of a high volume oil pump in a stock or mildly modified engine.

Cam gear or distributor gear wear is usually NOT caused by the high volume pump itself, but by insufficient internal engine running clearances.

Chevy V-8's, small block, big block, and 90? V-6 engines, all use splash lubrication to oil the distributor gear. Although higher RPM operation provides sufficient lubrication to prevent wear, low speed use can be a problem. The situation can become critical if a high volume oil pump is used. The high volume oil pump was developed for engines where bearing clearances were increased over stock. These work fine in racing engine applications, where extra clearance is provided in the short-block.

However, when a high volume oil pump is used in an engine with stock internal clearances, the increased volume of oil can't flow through the engine fast enough to relieve the back pressure created. This places an increased load on the distributor gear, and leads to accelerated wear.

Once the gear on either an 8620 steel cam or a cast iron cam is worn excessively, the cam itself must be scrapped! There is no repair for this problem, and the only option is to buy a new cam. To eliminate this annoying and expensive problem, we offer a simple, do-it-yourself way to help oil the distributor gear and reduce this accelerated wear in Chevy V-8 and 90? V-6 engines.

On these engines, the lower portion of the distributor housing drops through the oil gallery that supplies oil to the lifters on the passenger side of the engine. Two rings at the bottom of the distributor housing seal the top and bottom of this galley. Oil flows around the distributor, between the two rings.

Solving distributor gear wear is as simple as filing or machining a .030" groove in the bottom ring of the distributor housing. A three cornered file can also be used.

The distributor housing should be grooved in any engine operated for extended periods at low engine RPM. With the distributor installed in the engine - ready to run - the groove should face TOWARDS THE CAMSHAFT. This will provide a reasonable flow of oil to lubricate and cool the distributor gear and cam gear as they operate.

Remember to keep the groove facing the camshaft, and be sure to use the correct Crane high silicon, copper alloy distributor gear for best results.

73Z28LT
05-11-2007, 10:20:10 AM
thanks for all the info...should help alot of people..

ric70ss
05-11-2007, 03:33:13 PM
should of posted this in the top sticky

rscamaro73
05-11-2007, 10:03:30 PM
should of posted this in the top sticky

Good point. Done ;)

jteu2002
05-13-2007, 02:34:52 PM
can someone contact crane and ask how whe can keep the groove facing the front

sinse whe need to turn the thing to get the advance right

fabio
06-05-2007, 05:38:28 PM
with only 10% more than stock I wouldn't worry about doing the mod. I believe the z28 pumps and also the stockers with the upgraded spring are 10% increase and I never heard of this type of failure.

MrWylde
07-25-2007, 08:31:12 AM
I talked to all the local dealers around here and none of them new of this change either, however all of the pumps they have now have the warning but they can't order the heavy casting through they're computers yet. all are going to get a hold of melling to straighnten this out,,,, my question is, did this change affect the m77hv for the big block also, mine does not have the warning slip in the box but with the cost of this engine it's almost scary to consider.

sleepybu
07-28-2007, 04:23:28 PM
i orded an other one the performance one with 10% more volume and thick body
15522




that number ain't worken for me:whine:

CamaroMan79
08-10-2007, 09:16:05 AM
I have a M55HV I bought last year. Should I buy a new one?

thrasher
08-13-2007, 02:57:45 AM
The 10553 is the pump to buy to equal the old M55A. Melling is going to correct the part number issue meaning sometime this year the M55A will be returned to its former glory and the weaker stock body will have a differnt part #, but when it will be corrected this year is not clear yet. But for now buy the 10553.:bowtie:

That's one option. But look this page from Milodon.More specifically look at pump ##18755
Small Block 350 & 400 - Standard volume and pressure 18755

http://www.milodon.com/oil-system/oil-pumps.asp

The Melling 10553 is up to 80 bucks:dumper:
If you order the Milodon pump from their website its like 35 bucks including shipping.I mention ordering from the website because both Jegs and Summit don't have them in stock and will have to special order them.Oh, and their price... 35 bucks.

I ordered one of the 18755 pumps from Milodon last Monday and haven't seen it yet.That's pretty much normal for here.Makes more sense to me to pay 35 bucks and just change the spring to get a little more pressure for a total of what...38 bux max.

*EDIT*
It's been two weeks now and still no oil pump from Milodon.

thrasher
08-30-2007, 06:13:43 PM
Milodon has called to let me know that the standard oil pumps are out of stock.They will not be available for about three months.When Melling started charging big bucks for the standard pump people started ordering these and the supply quickly went away.

Tom, the person I was talking to at Milodon told me the gears and shaft are steel and not powdered metal.

bigdud5435
09-20-2007, 04:28:26 PM
thank you everyone for all of this info, I almost put this pump in until I read this. I have over 5 thousand into this 383 and I would of been pissd if this bulshit would of broke my motor. I ended sending the other pump back and ordering a M series pump..thanks

78LT383
09-20-2007, 04:57:23 PM
That's what I did too.

http://i51.photobucket.com/albums/f382/78LT383/Engine%20Build/th_IMG_0588.jpg (http://i51.photobucket.com/albums/f382/78LT383/Engine%20Build/IMG_0588.jpg)


I gave away the one I almost used.

epixlo
09-30-2007, 08:38:45 PM
sorry to bring up an old thread, but just wanted to share these pics.. I was driving this summer and about 1000 miles on the new motor I lost ALL oil pressure and thought I spun a rod bearing. Just this weekend I had a chance to pull the motor.

Taking the engine apart showed this:
http://lh5.google.com/epixpc/RwAfVtaWlPI/AAAAAAAAC-Q/wQkp6zI6EK4/s800/DSC_0447.JPG

http://lh4.google.com/epixpc/RwAfSdaWlNI/AAAAAAAAC-A/fvPY9gzlZmI/s800/DSC_0445.JPG

That is the Melling M55A Oil Pump, was broke right in half. The oil pickup was just sitting in the bottom of the pan when we removed it. The bearings were toast, some of the rods look like they may be toast as well, also the crank is most likely trash.

I had put nearly 1000 miles on the engine before this happened. I'm guessing it may have been caused when we put the oil pickup in we needed to force it, but that was at the opposite end of the pickup, could just be a really bad casting of the oil pump too.. no matter what it sucks but it will be rebuilt.. Plans are to take block, crank, rods, etc to machine shop this week to find the extent of the damage and plan from there.

K5JMP
09-30-2007, 08:42:52 PM
Sorry you got bitten. I was lucky enough to hit either side of this issue. Best of luck, and cheap to get her runnin' again.

And welcome!! Low post-count;)

78LT383
09-30-2007, 09:22:46 PM
I'm so thankful that this thread saved me from the likely failure I would have had. It cost me some money, but not nearly as much as a failure would have cost. I'm sorry you experienced the problem epixlo, but thanks to the rest of you for spreading the word!

Ztoy
10-01-2007, 08:54:48 AM
Welcome from Battle Creek epixlo! When did you install that pump and was the pump bought brand new when installed? I have one of those in my motor, but was built right before all this came out. I just had it sitting on the shelf for a year or two before finishing the motor. After I get my move done I'm going to pull the motor to change the rear seal and I'm going to go ahead and replace the pump at the same time.

epixlo
10-01-2007, 12:12:59 PM
Welcome from Battle Creek epixlo! When did you install that pump and was the pump bought brand new when installed? I have one of those in my motor, but was built right before all this came out. I just had it sitting on the shelf for a year or two before finishing the motor. After I get my move done I'm going to pull the motor to change the rear seal and I'm going to go ahead and replace the pump at the same time.
Hello from here in Kzoo! I bought the pump brand new from Summit I believe.. I kept all the receipts, but anyways... The engine was installed early last fall, then I put about 200 miles on the engine before the truck (GMC Typhoon) went into storage. Pulled it out this spring and put another 800 miles on it. While driving to a car show about 40 miles in the trip out of the blue I lost all oil pressure. Towed it home, went to show in another car, enjoyed show and just this past weekend was able to pull the engine with the original assembler. I just sent an email to melling with pictures and talked to them on the phone.. so far it sounds like I'm SOL but we'll see. Theres no reason this pump should have broke like it did.

Ztoy
10-02-2007, 07:56:59 AM
nah, they'll deny, deny, deny. But I did have an issue with comp cams, and after I talked to them and presented my case with lots of tact, they replaced it at not cost. So I guess you never know....good luck in your case anyway.

epixlo
10-02-2007, 08:38:22 PM
Little update:

Talked to George from Melling on the phone yesterday, he got the pictures but wants me to send the pump back to Melling (via Summit Racing).. so right now I'm just trying to get in touch with someone at Summit that can help me out to get Melling the pump, which they want to inspect.

I took my parts to the machine shop yesterday and they looked everything over.
Basically here is the damage done:
Block - Needs to be honed, thus need new piston rings
Crank - Bent.. I need a new crank
Rods - Eagle H-Beam Rods need to be replaced
Main Caps - 2 Center Main caps were damaged so I need to replace them
Bearings - pretty much all toasted so need to be replaced
Oil Pump - of course needs to be replaced with an M-Select pump this time.

78LT383
10-02-2007, 08:45:11 PM
That sounds pretty severe for an oil pump failure. Bent crank? wow. Any more pictures of the carnage?

K5JMP
10-02-2007, 08:46:45 PM
Yup, that's the normal result of something like that. Could have been worse if it had seized a rod journal and chucked it. Was it a hi-RPM failure?
I hope they do right by ya... and will be watching to see what they say.

epixlo
10-02-2007, 10:13:43 PM
Yup, that's the normal result of something like that. Could have been worse if it had seized a rod journal and chucked it. Was it a hi-RPM failure?
I hope they do right by ya... and will be watching to see what they say.
Naw, what is weird was I was driving normally on a trip to a carshow 150 miles away so was at cruising speeds.. ~2000rpm when this happened. I drove 30 miles just fine, stopped at Wal-Mart to get some supplies and just down the road I saw the CEL light on, low oil pressure so I pulled over and got towed home.

Ordering new parts tomorrow so I can get this truck back on the road hopefully in a month. I'm a college student and this takes a big chunk of my savings so it sucks.. ya I hope Melling decides to help me out that would be great.

78LT383
10-02-2007, 10:44:38 PM
wow, I had a failure like that in college. It's no fun changing an engine out in a friend's gravel driveway during finals week so I can drive it home before being kicked out of my housing for the summer. I hope it works out better for you!

Ztoy
10-03-2007, 08:06:38 AM
wow, I had a failure like that in college. It's no fun changing an engine out in a friend's gravel driveway during finals week so I can drive it home before being kicked out of my housing for the summer. I hope it works out better for you!

a real canundrum....:confused:

epixlo, it could have been worse, but man, replacing a crank 'ain't cheap'. Not sure about your finances (no need to go into that) but if you can nows the time to upgrade some internals for bigger hp applications later....;) . Either way, hope all goes well for you over in the zoo.....

old blue 75
10-03-2007, 09:13:49 PM
Hello fellow Michiganders. Sorry to hear about you broken pump.:( I have one in my truck motor as well, hope i don't have the same problem .

Ztoy
10-04-2007, 08:28:58 AM
Welcome to a great site old blue, pretty part of the state around Holland.....hope you like Tulips, lol. Well I'm still a Michigander for a while yet. Battle Creek here.

REARSPROCKET
10-12-2007, 11:45:44 AM
That oil port area of the distributor body sprays oil like crazy, because of the loose fit between the block passage and the distrbutor body. So I really don't think a groove is required on ALL engines at least not mine. The only time that port doesnt leak or spray oil is when the block is chamfer for an o-ringed distributor body like the new MSD billet bodies.:bowtie:

curtg21
11-17-2007, 06:33:32 PM
Shoot! I just purchased a m55hv before I read this. My new engine will make 450-500hp and be raced twice a month. Do I need to get a different one?

78LT383
11-17-2007, 10:03:01 PM
Shoot! I just purchased a m55hv before I read this. My new engine will make 450-500hp and be raced twice a month. Do I need to get a different one?

Yes.

HULKZ28
11-20-2007, 10:28:23 PM
Very interesting, I lost a dist. gear on my last motor with a HV pump but it was a comp magnum 280 cam...Also the dist has to be properly shimmed..
good info
hulk

REARSPROCKET
11-22-2007, 12:47:41 PM
Guys please buy the part# 10553 Std. volume heavy case for piece of mind (spend the extra cash), your motor is worth it! They are going to correct the part numbers, but who knows when? http://www.summitracing.com/search/?keyword=10553&dds=1 :bowtie:

curtg21
11-27-2007, 03:03:26 PM
that number ain't worken for me:whine:
The correct part number is 10552

epixlo
12-21-2007, 09:00:41 AM
Hey guys.. me again.. got a response from Melling just yesterday. heres the story.

Well way back in June my GMC Typhoon suddenly dropped oil pressure and I had my Typhoon towed home. Pulled engine and found the Melling M55-A pump was broke in 1/2 when we removed the engine and pulled the oilpan. Later on I found out that Melling made a design change to have a thinner/weaker casting to save $$$, and there was no notifications to the consumers about the change.

See this thread for more info:
http://www.syty.net/forums/showthread.php?t=52817&highlight=melling

After contacting Melling, they sent me several forms and requirements needed to send the pump back along with receipts of machine work/part costs to repair my engine ($2500+).

Today I received a response back where they acknowledged the broken casting but warranty was denied due to it being used in a 'performance application'. I assumed this would happen, but I had nothing to lose..

I can scan the response I received when I get home.. but here is a jist of what was mentioned:


Condition of Received Part(s): The bolts are tight, the gears turn within specifications. The casting is broken off at the mount pad.

Analysis Comments: We did see the broken casting, this pump was used in a performance application, we send a warning sheet with this pump stating; use M Select pumps for anything that is not an original stock application.

Analysis Results: The Melling Warranty does not apply to pumps used in a performance application. We did not find a manufactures defect in the pump or in the workmanship.

*I bought the pump back in the spring/summer of '06, no sheet stating use of M-Select was included! I have checked with others including sellers of the pump and they mentioned that this Warning Sheet was not attached with the pumps until recently. Did not finish assembling engine until fall '06 and put directly into storage. Next spring got Typhoon out and put apprx 1000 miles on new engine w/o a problem til the failure occurred.

Just a warning to you guys, that Melling was very shady about this. Talking with them on the phone I felt like I was being spoke to like this oil pump failure was my fault. Melling knew I posted the original thread and questioned me about it on the phone, from which I took down the pictures of the broken pump. Ed Hess (another SyTy owner) has had the same problem, along others while searching around the net.

Here are pictures of the oil pump where it broke in half, you can easily see the casting broke:
http://lh4.google.com/epixpc/R2rQLjT_rpI/AAAAAAAAELo/sLtkWGJJsJc/s800/DSC_0445.JPG

http://lh4.google.com/epixpc/R2rQPjT_rrI/AAAAAAAAEL4/0gPMyrmD7OU/s800/DSC_0447.JPG

http://lh5.google.com/epixpc/R2rQQzT_rsI/AAAAAAAAEMA/sN4rBVTsexg/s800/DSC_0448.JPG

They still have my broken pump, I have till Jan 7th to request it back, not sure if it worth the shipping or not.. This is a known issue by Melling and they know darn well that this pump has been used for years by engine builders and they decided to make the changes w/o letting anyone know.

JJFarmer
01-04-2008, 08:02:46 PM
After reading this post, I went down and dug out a new pump I had for the 70 rebuild. Sure enough, the weaker pump design. I called the tech line at Mellings and they told me I did have the wrong pump for a HIPO install. I bought it about 2 years ago. I ask him if I was sorta' stuck with this wrong pump and I would have to just go buy another one.... and he said that he would send me the new pump, NO CHARGE. And sure enough, the Mellings 10553 new Select pump came in UPS. They did me right!!!!

curtg21
01-04-2008, 08:09:01 PM
They wouldn't do that for me!

kik_start
01-04-2008, 08:48:31 PM
After reading this post, I went down and dug out a new pump I had for the 70 rebuild. Sure enough, the weaker pump design. I called the tech line at Mellings and they told me I did have the wrong pump for a HIPO install. I bought it about 2 years ago. I ask him if I was sorta' stuck with this wrong pump and I would have to just go buy another one.... and he said that he would send me the new pump, NO CHARGE. And sure enough, the Mellings 10553 new Select pump came in UPS. They did me right!!!!


Did you have to send the old one back?

JJFarmer
01-04-2008, 09:03:01 PM
Nope, he said keep it. Probably cheaper to let me keep it than the shipping cost to get an open one back.

78LT383
01-04-2008, 11:29:52 PM
They did the same for me. I can't fault the customer service, just the rediculous decision to make this design change.

HULKZ28
02-28-2008, 07:48:06 AM
Hey guys, this one is mounted up on my 355...
HM55A, and on the tag- 95349A..
Is it the weak one?
Thankfully its on the stand and the pans not on yet..
Thanks Hulk

73Beater
03-22-2008, 02:26:50 AM
Is there any easy way to determine which pump I have? I had my engine built 3 or so years ago and I just put it in the car last weekend, now I see this. Arrggg, time to drop the pan.

mountainmuscle
04-20-2008, 08:06:14 PM
Guys please buy the part# 10553 for piece of mind (spend the extra cash), your motor is worth it! They are going to correct the part numbers, but who knows when.:bowtie:

Man i am confused on the part numbers!

I am going freaking crazy with a 350 chevy plant and a car that cant get me to work. I am running .30 over on the pistons with a .125 dome. The heads are 64cc with 2.02 stainless. Running a mild lunati cam.

This is probably "high performance" . It is all brand new, ready to put in except for the oil pump.

So what I am looking for is the latest part number from melling regarding the oil pump. I dont think i really need the HV pump, but that is also "old school" thinking as they used to be good for up to 500 hp.

So basically, to keep me from going insane and swearing off muscle cars forever. Please, help..

This engine needs to go in by tomorrow night or I am toast!

JJFarmer
04-20-2008, 11:16:40 PM
I would buy the Select version heavier casting if using a Mellings. Might even look at a Seal Power pump instead.??

78LT383
04-21-2008, 09:46:37 AM
http://store.summitracing.com/partdetail.asp?autofilter=1&part=MEL%2D10553&N=700+309179+4294908216+115&autoview=sku

Cardinal
04-21-2008, 11:22:54 AM
I can't believe that this is still going on after two years! Melling is a good company that's put their reputation on the line with this debogle.

In hind sight, they should have made the new pump a COMPLETELY different part number which would have minumized the consumer's exposure to the pump failure issue.

curtg21
04-21-2008, 05:32:21 PM
Their fix for this was to put a little yellow piece of paper in with the pump that says it is not for performance use.:confused:

mountainmuscle
04-21-2008, 08:06:07 PM
I can't believe that this is still going on after two years! Melling is a good company that's put their reputation on the line with this debogle.

In hind sight, they should have made the new pump a COMPLETELY different part number which would have minumized the consumer's exposure to the pump failure issue.

Man it has only been going on with me for a week and i am allready tired. I can imagine how you guy's feel after two years.Jeez..

But, I did call Melling today and i have a select pump that put's out about 10% over stock. It also has a bolt on screen which i prefer. I think this will work fine for what i am doing. Thanks everyone for all the help and advice.

Wish me luck! Starting a new engine is always a freaky thing for me. So much to assemble and check as you go. I hope it's right!!:bowtie:

comp
04-24-2008, 10:20:17 AM
Their fix for this was to put a little yellow piece of paper in with the pump that says it is not for performance use.:confused:
thats BS

78LT383
04-24-2008, 01:04:30 PM
Man it has only been going on with me for a week and i am allready tired. I can imagine how you guy's feel after two years.Jeez..

But, I did call Melling today and i have a select pump that put's out about 10% over stock. It also has a bolt on screen which i prefer. I think this will work fine for what i am doing. Thanks everyone for all the help and advice.

Wish me luck! Starting a new engine is always a freaky thing for me. So much to assemble and check as you go. I hope it's right!!:bowtie:

That's exactly what I did. My only regret is the (new) higher cost.

mountainmuscle
04-24-2008, 09:27:19 PM
That's exactly what I did. My only regret is the (new) higher cost.

$90 at the counter, plus screen. But, the engine is in the car and i can finally go back to work...

purpleflame
05-12-2008, 03:48:59 PM
$90 at the counter, plus screen. But, the engine is in the car and i can finally go back to work...

so I called and talked to the tech at melling and he informed me that they have changed the casting several times and the new ones are better than the ones from the old days. he said the problem he has found is that if you buy one from your local parts place you dont know what your buying it may say M55HV on it but it may not be a melling pump there are a lot of cheap chinese knock offs out there so be careful they look just the same. i am gonna take pics of my pump tonight and send to him and he said he would let me know if I have one of theirs and if its good or not. will post back when I hear from him, he did say the new ones in the select series are the better way for high performance apps, but if you got questions feel free to call he will set you straight on what you have or dont have. ask for Greg Richmond.

purpleflame
05-13-2008, 12:45:47 PM
so I called and talked to the tech at melling and he informed me that they have changed the casting several times and the new ones are better than the ones from the old days. he said the problem he has found is that if you buy one from your local parts place you dont know what your buying it may say M55HV on it but it may not be a melling pump there are a lot of cheap chinese knock offs out there so be careful they look just the same. i am gonna take pics of my pump tonight and send to him and he said he would let me know if I have one of theirs and if its good or not. will post back when I hear from him, he did say the new ones in the select series are the better way for high performance apps, but if you got questions feel free to call he will set you straight on what you have or dont have. ask for Greg Richmond.
K I sent the pics in and he told me mine was a good pump casting and shouldnt be a problem but why is it I still dont feel warm and fuzzy about it.
think I will buy the select series just for the insurance of it.

78LT383
05-13-2008, 12:57:43 PM
For what it's worth, I agree. What Melling calls a "good pump" seems to have dramatically changed.

mountainmuscle
05-14-2008, 10:22:08 PM
Mine makes a bunch of racket! But it works... I just keep my eyes on the guage.. Almost sounds like a rod knocking, but the bottom end is tight and i have just "accepted" the fact that the oilpump is noisy.

Ztoy
05-15-2008, 09:12:48 AM
a 'rod knocking' sound....man I've never heard of an oil pump making that kind of sound. Not sure how it could with the gears fitting and engaging so closely in addition to the oil in there....ever taken one apart? Not much in there to knock or even rattle is there?

Cardinal
05-15-2008, 12:17:20 PM
Rods are the usual culprit but piston slap will also cause a knocking noise. So will a bad mechanical fuel pump.

I think that you should investigate the noise before it becomes a catastrophic failure.

mountainmuscle
05-16-2008, 08:53:02 PM
Rods are the usual culprit but piston slap will also cause a knocking noise. So will a bad mechanical fuel pump.

I think that you should investigate the noise before it becomes a catastrophic failure.

Guys I know it sounds crazy but it is the pump. I first noticed it as i was installing the pump and then when priming. It's not quite as loud as a rod knocking, but it's there.

When i was building the engine, I called melling, they told me to get a new pump. I took the pan off, and pulled the pump. Then, I got a new pump and installed it. Itstill made the noise, although this one does make less noise.

You know how it is, when you build one and drive it, you hear everything.. I have just come to accept the fact that the pumps tend to make some racket.

78LT383
05-17-2008, 01:57:13 PM
I wonder if something is wrong with your oil pump drive shaft. You did remember to put the nylon sleeve on the pump before installing it, right?

mountainmuscle
05-18-2008, 08:27:15 PM
I wonder if something is wrong with your oil pump drive shaft. You did remember to put the nylon sleeve on the pump before installing it, right?

It's got the metal shaft, no lock. Both pumps made the noise outside of the engine, spun by hand, before they were ever installed.

mikesgotspeed
07-29-2008, 12:22:31 AM
with only 10% more than stock I wouldn't worry about doing the mod. I believe the z28 pumps and also the stockers with the upgraded spring are 10% increase and I never heard of this type of failure.

fabio, he is not talking about 10% more than the stock volume pump. He is talking about a performance pump with 10% more than the Hi Volume pump.

I have heard of and have seen this problem with big blocks as well and a crane billet cam. Their Tech Experts say a well built engine does not need a Hi Volume pump and the pump is the main cause of the problem not the oiling. This is because the pump is putting excessive pressure on the drive gears all the time at all RPMs. Unless you are using an All Out Competition Engine a std volume pump is all that is needed. I have a std volume pump with a modified pressure spring in a big block with a little extra clearance and it has over 60 pounds of pressure at 3,000 and about 78 pounds at 6,400. I would try to buy the cams that use the newer gears that are compatible with stock steel or Iron gears that come on the distributors anyway. Those Bronze gears are very expensive and were only meant to be run on all out race engines. They were not meant to be used on street cars period.
Just ask for the cams with the compatible gears.
Hope this helps some of you.

mikesgotspeed
07-29-2008, 12:25:23 AM
can someone contact crane and ask how whe can keep the groove facing the front

sinse whe need to turn the thing to get the advance right

All you have to do is install the distributor set the timing where you want it, mark the front of the distributor that faces the cam, pull the distributor and cut the groove accordingly and reinstall the distributor and set the timing. The groove will be in the right place.

mikesgotspeed
07-29-2008, 12:33:14 AM
he is not talking about 10% more than the stock volume pump. He is talking about a performance pump with 10% more than the Hi Volume pump.

I have heard of and have seen this problem with big blocks as well and a crane billet cam. Their Tech Experts say a well built engine does not need a Hi Volume pump and the pump is the main cause of the problem not the oiling. This is because the pump is putting excessive pressure on the drive gears all the time at all RPMs. Unless you are using an All Out Competition Engine a std volume pump is all that is needed. I have a std volume pump with a modified pressure spring in a big block with a little extra clearance and it has over 60 pounds of pressure at 3,000 and about 78 pounds at 6,400. I would try to buy the cams that use the newer gears that are compatible with stock steel or Iron gears that come on the distributors anyway. Those Bronze gears are very expensive and were only meant to be run on all out race engines. They were not meant to be used on street cars period.
Just ask for the cams with the compatible gears.
Hope this helps some of you.

And by the way, I hope you guys know that the oil companies have taken out the needed hi load lubricating ingredients that are needed for flat tappet cams from the motor oils. They did this a couple of years ago because almost all engines are now roller cam engines and they don't need it and the EPA was on their butts too. Comp Cams and Crane Cams as well as others have reported more cam lobe wear problems and worn out lifter bottoms over the last couple of years than they have had in their entire existance. They have an additive that is needed on initial start up and most of the time this is the only time it is critical. Call your cam companies and ask about it.

REARSPROCKET
12-10-2008, 04:37:14 PM
10553 is the baby, you can add a Mr. Gasket # 26 high pressure bypass spring and you'll be good to go.

tim_bo16
04-08-2009, 12:46:43 AM
so these pumps still crap? i just picked up a m55a from jegs. and i just NOW found this.. what the hell.

bsa
04-20-2009, 12:14:31 PM
I just finished building my 327 with all new parts. We installed the oil pick up screen with their tool and it fell out and ruined the engine within 50 miles. It was sent back to them and of course they say it was put in wrong. Hard to do it wrong with their tool. Be very careful with Mellings oil pumps. :( :mad:

BondoSpecial
04-20-2009, 12:17:02 PM
there is no way a gear rotor pump should be making noise. That is not going to live long and I would not write that off as okay

mudtrux
05-31-2009, 06:25:49 PM
I'm just curious if this is still an issue with the m55's? I want a std volume pump that won't snap off :eek:

All the beefier ones say they have increased volume and I don't need to empty my pan any faster

408maro
07-04-2009, 03:44:31 PM
im also curious i need a pump ASAP! and dont wanna spend a fortune for just the pump

78LT383
07-05-2009, 11:38:17 PM
I haven't heard anything different.

mark.moore1689
07-06-2009, 03:53:30 AM
oh hell i just put in a 55hv in my 383 and ran the crap out of it on the dyno it made 90 psi at max rpm 8500 are you saying they are junk and will fail? I use 2 oil pressure gauges because im paranoid already,i blew up a 327 because of a bad pump years ago. I've got about 8,000 invested in my motor now and this news is freaking me out !!!!!

ORANGE77
07-12-2009, 06:14:55 PM
Has anyone used a Milodon pump #18755 standard vol./press. or #18756 standard vol./high press. Thrasher, did you ever get your Milodon pump yet? How's it working for you. What did you use for a pickup, looks like that has to be added. I looked at Jeg's and both pumps are on back-order, should I get in line? ;)

tim_bo16
07-14-2009, 08:05:18 PM
also havent heard anything different on the 55 pumps. i didnt end up using mine. i ended up going with their select 10550 pump. high volume, stock spring. 6 qt. pan, no problems. 40 lbs everywhere.

408maro
07-19-2009, 06:02:55 PM
Has anyone used a Milodon pump #18755 standard vol./press. or #18756 standard vol./high press. Thrasher, did you ever get your Milodon pump yet? How's it working for you. What did you use for a pickup, looks like that has to be added. I looked at Jeg's and both pumps are on back-order, should I get in line? ;)
also curious about the pickup and shaft. im so confused guys, which mellings oil pump can i get and not have to worry about it??

Al Weyman
07-19-2009, 06:59:55 PM
Bloody hell I have just finished installing a new engine with one of these pumps fitted which I bought about 6 months ago if i had read this last week I could have changed the pump. I mig welded the pick up on which should hopefully help and I run on rubber engine mounts, time to start worrying? Funny thing is though after reading this I have just compared this to an old pump I had lying around out of a mexican Goodwrench engine and the Melling looks stouter if anything. I bought the pump from Real Steel in the UK and they know what I want them for as one of the guys there has even come to the track to watch me race, I will be very disappointed with them if there is an issue and they have not advised me.

stinkboy
07-19-2009, 08:14:49 PM
i used the melling HV55 with the melling shaft but used the proper pickup for my milodon pan height.

on my rebuild im 85psi at idle 65-70 running and 50-55 at idle.

Al Weyman
07-20-2009, 04:00:38 AM
Well his engine has no problems what so ever with oil pressure despite having a loose fitting follower causing a lot of oil up to one rocker and running on 10/40 synthetic. I ran it up yesterday and I had to be careful as it was going up to 90psi cold and I have plugged the oil filter bypass valve, it dropped back down a tad when warmed up so should be OK (I hope) as long as the thing don't break off!!

ORANGE77
07-21-2009, 11:52:22 AM
also curious about the pickup and shaft. im so confused guys, which mellings oil pump can i get and not have to worry about it??
p.m. sent :)

70 splitbumper
09-02-2009, 04:00:50 AM
What brands are affected? Does Melling make pumps for others to market?
Have there been any issues with Milodon? I am putting together a 650hp big block and the last thing I need is for a pump to fail. I would go postal if that happened.

lazr_guira
10-28-2009, 07:52:16 PM
JESUS CRIST MAN! I just installed a new MELLING 55A that i bought from my local speed shop. Does this mean i'm gonna have to take it out?:mad:

Al Weyman
10-29-2009, 04:59:51 AM
I have just finished 8 road races of 20 minute duration plus a similar amount of qualifiers with the pump fitted and so far I have had no problems excellent oil pressure even after a hard 20 minutes running still showing 65/70psi and running on thin fully synthetic oil. I think the answer must be to make sure its installed correctly and the pickup not wedged up against the sump pan. I am just reuilding an engine for my 2nd car and am refitting the Melling pump that was in that (its only done 10 minutes running and the engine expired due to a block and head problem so no swarf in the sump). Here is the odd thing as well and I can take pictures if you like, I have compared an old style pump with this so called faulty one and the newer model definitely looks a stouter casting, I will say both the later pumps I am using were purchased in the last year so maybe have been upgraded.

troutman
11-02-2009, 08:57:09 PM
I have a melling M55006 rev.C. w/ solid motor mounts that is about 3-3&1/2 yrs. old. Is my rev.C the good one?

troutman
11-08-2009, 07:54:45 PM
I answered my own question by e-mailing melling company and they stated that i do have a bad pump and i need to use their select oil pump. They didn't offer to replace this junk on their part. I will have to r&r the motor and i will use a fac. GM pump and install the spring w/ my high press. one. It would have been wonderful if they had the warning sheet in the box when i purchased it. I really hate that other guys have lost expensive motors from this.

Al Weyman
11-09-2009, 02:58:24 AM
So what about my two that is less than a year old and I use rubber mounts? One I was going to refit in the rebuild I am doing at the moment as its had virually zero use and the other is in a running motor. These engines will not see over 7000rpm.

troutman
11-09-2009, 08:17:15 PM
Al, you are ok w/ rubber mounts. Imo, never will i trust a melling product. I can get a GM pump for a little more money and make a hp w/ GM's cheap spring. I also don't use a hv pump, just a hp pump.

lazr_guira
11-29-2009, 03:47:23 PM
I can't belive it. I guess i had one of the bad ones. It gave out and i fried my bearings. I'll never buy a Melling Product Again! Can't believe they would change the design to save a few more pennies and screw every thing up.How could do that to us?

Phaedrus44
12-02-2009, 09:38:35 PM
So is this still an issue? The links in the original thread don't work anymore. When I bought the oil pump for my street stock, I bought a Melling Select 55HV pump. Am I cool?

78LT383
12-03-2009, 07:50:52 AM
So is this still an issue? The links in the original thread don't work anymore. When I bought the oil pump for my street stock, I bought a Melling Select 55HV pump. Am I cool?

The Select pumps have the old casting, so you're in good shape. You paid an extra $50 to get the pump casting that used to be used for the $12 pump.

78LT383
12-03-2009, 07:52:41 AM
Al, you are ok w/ rubber mounts. Imo, never will i trust a melling product. I can get a GM pump for a little more money and make a hp w/ GM's cheap spring. I also don't use a hv pump, just a hp pump.

GM is buying the pump from Melling with the "low cost" new housing. In fact, several pages back one of the earlier posts revealed that it was GM's request for cost reduction that drove Melling to change the casting.

You'll have to buy a higher priced pump to get the old casting without the fatigue problems.

Brown`77Z28
12-03-2009, 02:08:27 PM
What pump is used in the GMPP crate engines ???? does anyone know????

Skip Fix
01-06-2010, 11:05:15 AM
Talked to my machine shop today. My 409 project calls for the same pump. They have yet to see one broken and they do alot of motors.

78LT383
01-06-2010, 11:07:54 AM
We all hope you don't have to show them thier first.

It is all a question of risk management. Not all of them fail, but if you're the one in 100 that does fail you feel all of the pain.

Al Weyman
01-06-2010, 11:22:24 AM
I have just built and ran up the engine in my 2nd race car the 3rd Gen Camaro and oddly enough I have used this same pump in both (already built both) one of these 55HV's. Anyhow on my engine in the 2nd gen I am using a standard filter arrangement and no oil cooler on the 3rd gen I am using a remote filter and an oil cooler and same 10/40 fully synthetic oil. Engines similar specs both with the high pressure high volume pump and the one with the cooler shows a straight 15 to 20 psi pressure drop. Not critical and still runs at 50psi hot at 1000rpm and 65 when revved a little but the engine without the cooler shows about 65psi and 80 revving so just goes to show if running a cooler and/or remote filter you may need the high pressure, high volume unit. BTW I may have said this before but like the 2nd gen engine when I ran the oil pressure up with the fully synthetic oil I found a significant difference on the strain on the drill than with the 20/50 mineral based Valvoline I was using so recon worth a couple of BHP or so running the synthetic. :-)

Skip Fix
01-06-2010, 08:40:16 PM
"We all hope you don't have to show them thier first."

Why I haven't ordered a HV55A yet either:)

I need a good pump with a 5/8 pickup for the Stefs pan I've got for it. Mellings Select with the anticavitation grooves only has a 3/4.

troutman
01-06-2010, 11:00:37 PM
78LT383 you are correct on GM's pumps being Melling. I finally found an old thick style pump from Summit that should work w/ my application.

Al Weyman
01-07-2010, 03:47:11 AM
"We all hope you don't have to show them thier first."

Why I haven't ordered a HV55A yet either:)

I need a good pump with a 5/8 pickup for the Stefs pan I've got for it. Mellings Select with the anticavitation grooves only has a 3/4.
Can't you modify the pickup, I did that when I used one of those pumps it worked fine.

f-body
02-27-2010, 09:06:59 AM
Ok so what pump am I spupost to use. I might be rebuilding the pump in my 4.3 and dont want to get a new light weight casting. Yeah its stock but I have friend two engines in the past 6 months and want the good oil pump.

jtscollect
02-27-2010, 09:33:46 AM
Good Morning:

Now, you all have me worried.

We are getting ready to upgrade our Oil, Fuel and Water Pumps.

We are looking at the JEGS catalog an the following Melling Oil Pumps and didn't now if they were related to the M55 series that everyone is talking about.

So far, these are the oil pumps that I'm looking at:

Melling 10552 SB-Chevy Oil Pump 10 more volume than OE SB-Chevy Oil Pumps Item# 689-10552 Only $64.99
Melling 10555 SB-Chevy Oil Pump 25 more volume than OE SB-Chevy Oil Pumps Item# 689-10555 Only $64.99
Moroso 22101 Racing Oil Pump Small-block Chevy Standard Volume Chevy Small-Block Item# 710-22101 Only $71.99
JEGS 23501 Oil Pump SB-Chevy Street/Strip/Race Item# 555-23501 Only $34.99

I need recommendations on other quality oil pumps; need standard pressure, but more volume (10-25%).

Please let me know.

I just did a rebuild in the past 18 months and don't want to have to rebuild again due to El Crapo parts!

Thanks.

Jim T
Red Bomber

yobin67
02-28-2010, 02:55:41 PM
I got the 10552 for my new engine.I had Kevco make me a custom pickup to fit my pan.The pickup is 3/4",and bolts on as well as presses in.

http://i553.photobucket.com/albums/jj363/yobin67/oilpumppickup.jpg

mudtrux
02-28-2010, 03:40:43 PM
I've got a theory that when people install there pickups, the pump is bolted to the block. When you hammer on the pickup the narrow part of the body takes the hammer/stress and may weaken it???

When I did mine I laid the pump on the bench with the hole up and used a install tool

Other thoughts?

Al Weyman
02-28-2010, 04:46:17 PM
To be honest I really fail to see a company like Melling could possible continue to knock out a defective pump and like the last poster I also suspect something else is going down here like interference with the pick up and pan. I have oneof these pumps in each of my race engines and hope I am not made to eat my words but they seem OK thus far.

yobin67
02-28-2010, 06:51:20 PM
I installed mine in a vise,using 2 short studs to keep the flange lined up where it belonged.

NYH1
03-01-2010, 01:08:00 AM
Below is my complete oil system right down to the pan bolts, minus the Amsoil oil and oil filter that I'm going to use. From what I just read in this post, I think I'm ok with the oil pump I picked. I didn't know anything about this Melling oil pump issue!


I choose this pump for three reasons. 1- My machinist recommended that I use it. 2- It was highly recommended by a member on a another forum who has given me A LOT of really good information. Everything he's ever told me has been true, he's never steered me wrong. 3- I knew I didn't "REALLY" need a higher volume and/or pressure oil pump but I liked the approximate 10% over stock volume output, so it seemed like a good compromise.

Pump (http://www.summitracing.com/parts/MEL-10552/)
Pick up (http://www.summitracing.com/parts/MEL-12558/)
Pan (http://www.summitracing.com/parts/MOR-20170/)
Rear baffle (http://www.summitracing.com/parts/MOR-23000/)
One piece gasket (http://www.summitracing.com/parts/FPP-1880/)
Pump stud (http://www.summitracing.com/parts/ARP-230-7004/)
Pan bolts (http://www.summitracing.com/parts/ARP-234-1801/)

ahale2772
03-18-2010, 05:03:01 PM
any one know if sealed power usees the same casting as the bad pumps? i have a z2244143 pump in my motor right now its a high volumn std pressure

BlueCamaro
03-18-2010, 10:45:29 PM
is it just t he m55 that is bad?

Is this pump good to go? http://www.summitracing.com/parts/MEL-M77HV/

Al Weyman
03-19-2010, 08:22:24 AM
Surely this is sorted now, the company would go under in no time if it wasnt!

ahale2772
03-21-2010, 10:03:46 PM
that sealed power pump was bad replaced it with a m-select

crakarjax
03-30-2010, 12:38:23 AM
How do you know? I notice the picture of it says M55HV right on it, at least on the RockAuto site.

tater_79
03-30-2010, 08:54:21 PM
So I finally found my receipts from Summit. My pump was purchased Jan 2005, so it looks like I'll be getting a select pump on order. The good thing is that I'll be pulling my tranny for a re-build and I'll go ahead and pull the motor and change the pump at the same time.

Even though the pump was purchased 5 years ago, I just got this motor together about 9 months ago. I have about 400 miles on it total. This really sucks!!

Al Weyman
04-04-2010, 02:39:09 AM
Just got back form the track with my 3rd gen and had to pull out of the race as I have a low oil pressure issue during qualifing. The pressure steadly dropped to around 20 psi so i pulled up. Now hot or cold, ticking over or revved the pressure is a rock steady 20 psi without fluctuation almost like a pressure release valve is stuck, could I be another Melling 55HV victim?

mudtrux
04-04-2010, 04:24:44 AM
I think it breaks off so you have 0 oil psi, so no

Al Weyman
04-04-2010, 10:12:39 AM
Yes you are probably right, I was wondering it the pressure relief valve had stuck to be honest, wishful thinking probably!

81z377ci
05-08-2010, 01:49:00 PM
After reading this thread yesterday morning I went to work and immediately grabbed an M55 and a M55HV. The M55 looked to be the new casting but the HV was much more stout. Six years and four months since they changed the casting and I still have an M55HV with the old casting? We sell a lot of these pumps.

Did Melling maybe change the casting back by now? For how many I sell I doubt we'd still have a mess of the old castings at the warehouse. My system refers to the M55A as a "performance use" pump. I ordered one in to take a look at it, I'll let you guys know how it looks.

Al Weyman
05-10-2010, 03:31:16 AM
I must say I have a Melling 55HV on the bench at the moment and some older model pumps and it certainly looks stout enough to me compared with the old one, I bought this one about a year ago and think I will put it back in the engine. On the engine in my 2nd gen I have the same pump and have just done a hard 20 minute road race at Silverstone this weekend and it came of the track with 60 psi on 5/40 fully synthetic oil so seems to be performing well.

Mike-78 Z-28
09-18-2010, 09:36:50 PM
My friend went to look at a 95 Trans Am with a Vortech.Got over there and the pan was off because of a broken oil pump!

Skip Fix
09-18-2010, 10:54:31 PM
I saw one thread on another forum where they said Meliings has gone back to the old castings

wookie
09-30-2010, 11:25:45 PM
Updates?

bbc nova
10-01-2010, 12:10:27 AM
Thread is 4 years old.

BondoSpecial
10-01-2010, 12:30:10 AM
and still relevant b/c i am buying yet another sbc oil pump soon

Al Weyman
10-01-2010, 03:06:44 AM
I put one in my racing engine over a year and 20 odd races ago and its still going fine. I am confidentt he company would have resolved this long ago.

Happy_Meal
10-17-2010, 01:34:46 PM
If I understand this right, the change in casting involved the thickness of the metal surrounding the mounting bolt, right? Does anybody know what the thickness is of the new casting? I just bought an M55HV and would like to be sure its not going to break if I use it. Mine is approximately 5/16" thick measure outward from the hole. There's no warning sheet in the box about the casting, just a sheet telling you to check the clearances in the pan.

Al Weyman
10-19-2010, 06:14:43 AM
Mine is still going well up to about 30 races now!

Al Weyman
10-19-2010, 06:28:16 AM
And at the end of a 40 minute mini enduro on Sunday it was showing 60 to 70 psi on 5/30 fully synthetic oil without an oil cooler.

rookie
07-06-2011, 01:39:14 AM
I have read here that m55 pumps have returned to the good casting, have you guys seen anything on this.

I have always used m77 on my small blocks with no problems.

muscl car
07-06-2011, 01:45:43 AM
I have read here that m55 pumps have returned to the good casting, have you guys seen anything on this.

I have always used m77 on my small blocks with no problems.

i'm running a M55HV in my motor with no issues 60-65psi cold ,45-50psi warm 1100rpm idle 55-60psi cruise rpm pressure

rookie
07-06-2011, 01:48:02 AM
Forgot to add the link to the info I found.

http://speedtalk.com/forum/viewtopic.php?f=1&t=22465&hilit=+oil+pump+m55+casting

Cardinal
07-06-2011, 08:37:23 AM
I copied and pasted the reply that I got from Melling 01/27/2006. Unfortunatley, you have to read the whole post a couple of time before you can definatley understand which Melling oil pump to use and what one NOT to use in a praticlar motor!



Here's the reply that I got from Melling:

Cardinal,

Thank you for input ,we value our customers opinion.

Melling’s design of GM’s Small Block Chevy oil pump was updated in 2004, see attached bulletin. At that time changes were made to the standard volume, M-55 & M155, and the high volume, M-55HV & M155HV, pumps. The changes improved many aspects of the pumps as compared to the original GM pump. To respond to customers requests one of the areas that improved was the hot idle performance of the pump. Durability was improved by eliminating a possible failure mode as noted in the bulletin. Casting improvements allowed the wall thickness of the housing around the gears to be reduced to reduce weight. Additional support rips were added to the neck area on the high volume pump casting. For stock replacement applications the changes will only increase customer satisfaction with our products.

For performance applications Melling recommends an M-Select oil pump be used, especially in solid motor mount applications. Melling has available a full line of SB Chevy performance oil pumps. Not only does the M-Select line of SB Chevy performance pumps utilize the previous casting design but are available with design features to further increase performance and durability. In addition the M-Select pumps are CNC machined to exacting tolerances and surface finishes. The M-Select line was created to provide engine builders a cheap insurance policy to improve one of the most overlooked critical components in a performance engine build, the oil pump.

Melling is a world class designer and manufacturer of Original Equipment, Replacement, and Performance oil pumps. The changes implemented on the stock replacement GM SB oil pumps improved performance, durability, weight and cost. With the recent dramatic increases in raw material costs these changes have helped to reduce the cost increase that is passed onto our loyal customers.

I have attached the warning sheet (pdf) that is included in each Melling boxed oil pump. Some of our private labeled oil pump customers do not to have the warning sheet included in the packaging.

Thank You,

George Richmond

Tech.Mrg.

-----Original Message-----
From: Cardinal
Sent: Tuesday, October 17, 2006 12:37 AM
To: technical@melling.com
Subject: New FUBAR Melling HV M55 Pump


For your own sake, I think it would be in your best interest to recall the "new and improved" M55 small block Chevy high performance pumps, or change the part number, and/or put a disclaimer on them that they can fail if used in a high performance motor.

Trust me, you're going to ruin your business if you don't. I belong to three different boards (Gen II Camaro, Gen 1 S10, and a Gen III Camaro) and all three have posts from members warning others about the JUNK Melling oil pumps being put out on the market. More than one member has had problems. One went back to his engine builder who checked all of the pumps on inventory and found all of them had the new thinner casting. Another ordered a Moroso unit and it had the thin casting.

I sincerely hope that this is not a trend with your company. We've seen too many companies like TRW automotive and IBM (PC's) go down the tubes because of mismanagement and reduction in quality and/or performance of their parts. Melling oil pumps have been the benchmark for a top quality product and I sincerely hope that this event is an anomaly and not a trend.

Sincerely,

Cardinal

__________________________________________________ ____________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact the Melling IS&S Group
__________________________________________________ ____________________




M-55 and M155 GM OIL PUMP IMPROVEMENTS FOR 2004

In 2004 Melling Engine Parts will be releasing updated versions of the M-55 and M155 oil pumps. The new M-55 and M155 will have a new look due to a new housing and cover casting. The housing will now have a drilled outlet hole much in the same manner as the original GM pump. As compared to the original GM design the outlet hole has been re-positioned to improve the alignment with the bearing cap to improve oil flow up to the main oil gallery.

The cover design has also experienced a change. The relief valve bore is now machined as a blind hole with a step near the end for the relief valve to seat against. Leakage around the relief valve will be greatly reduced since the valve seats on the end of the valve bore. This will help to improve low rpm performance. This change eliminates the need for the press-fit plug and possible failure mode concerning the press-fit on the plug.

The changes to the relief valve are minor. The end configuration has been changed to match the chamfer on the valve bore. A 90-degree edge has been added to help clean foreign material off the valve bore wall.

The groove pin has been changed from a 3/32” diameter tapered pin to a 1/8” diameter straight pin. This change is to increase the strength of the drill to reduce tool breakage. Pin orientation will no longer be an assembly issue by removing the taper from the pin.

“Quality in all we do”


Melling Engine Parts has an oil pump for almost every application. Whether you need a stock
replacement pump, or one of our M-Select Performance pumps, we build quality into every one.
Special attention to performance and durability has been given to all of the new line of M-Select
Performance oil pumps. Take a look at what the leading manufacturer of oil pumps can do for your
performance lubrication needs. All pumps are tested for pressure and volume and hand turned before being bagged and boxed. The informational charts on the following pages will assist you making the correct choice for the MSelct
oil pump that best suits your needs. In Melling’s continuous drive to improve the quality and customer satisfaction of our products a series of design changes were recently made to the body casting used to manufacture the M-55 and the M155 family of oil pumps. Melling supplies these pumps to the Original Equipment market, as well as the aftermarket. The major design change was a weight reduction in the body casting. The lightening of the casting as and the drilling of the outlet hole resulted in a change in the appearance of the Melling pump. Melling will continue to use the old casting design for the pumps manufactured for our M-Select performance line of products. We highly recommend all performance engine builders choose one of our M-Selct oil pumps.

M-55HV 10550
“Very Important”

Casting Changes to the Small Block Chevy Oil Pumps Location of weight reduction done per General Motors request

rookie
07-06-2011, 12:09:47 PM
This is from 2010, your letter is 2006.

http://speedtalk.com/forum/viewtopic.php?f=1&t=22465&hilit=+oil+pump+m55+casting

BondoSpecial
07-06-2011, 12:21:38 PM
rookie thanks for the update. I had found that even the Summit cheap nodular pumps, which were advertised as having the extra thick neck, did, so I just skipped the M55 altogether.