Well we finally went to break in my 402 Chevy bbc and we got one hell of a suprise......... camshaft eaten in minutes. After 10 minutes of running above 2 grand there was horrible valve noise. Even though we new what happened... we tried to adjust again but it went to slop in seconds after just cranking it. The cam was a comp cams 280h cam put together with all the recommend components. It couldnt have been the oil because i used their additive and used old style straight 30w non detergent oil. We talked to the machine shop and they suggested that it was just a soft cam and they see that quite frequently with comp. My question is why are they building flat tappet cams that require such high spring pressure and not hardening the cams? The springs required (911-16) are the springs required for a roller set up. Has anyone else had this issue? Would you trust it enough to throw another one in or go to another manufacturer?

Same thing, same cam. Tried it again after grooving the lifter bores, and putting in some old weak stock springs. Second time it worked, changed springs back and ran for 4 years, ~3000 miles a year.

BTW that cam made 463hp/488tq in my 427 all done at 6k with 781 heads. Was a total brute of a street engine.


Went roller, I suggest you do too. Though I don't know if I've gained 25hp by doing so, at least I'm not waiting to hear the ticking....

Did you call Comp Cams when this happed? I'm very suprised that this happended as we've use their 268H cam in a few engines with zero problems.

What oil pump do you have on the engine? Standard volume & pressure? High volume & pressure? Wht oil pan? What oil controling devices: crank scraper? windtage tray? What was the oil pressure while you were running the engine?

How did you initially adjust the lifters (when the engine was on the engine stand or not running) and to what lash? How long after you got the engine running did you re-adjust the lifters? How did you adjust the lifters and to what tightness (1/2 or 3/4 or 1 full turn from zero lash)?

The valves were initially adjusted on the stand. The valves were adjusted by my father so i am not sure to what method. I am sure he did it correctly because he has been turning wrenches for a living and building motors for over 35 years. The oil pump is a high volume pump and the engine had good oil pressure. The oil pump was primed by hand prior to install and then the engine was cranked as well when in the car to insure oil pressure. Oil pressure was over 60 psi while running. The oil pan is a stock type 7 quart.

When we first heard the valve noise we stopped (about ten minutes in) and re adjusted. We then disabled the fuel and ignition and used the started to crank to watch the valve train with the valve covers off. Several went from adjusted to real loose to point where you could spin the rockers just from the turning from the starter. I have built a few engines and my dad has built a lot and have never seen this.

I plan to call comp first thing monday as this happened late friday afternoon.

I put a solid lifter Crane cam in my 70 Z28 last spring and everything went fine.

I put a crane in my 70 Z28 last spring and everything went fine. I would not try another Comp.

It couldnt have been the oil because i used their additive and used old style straight 30w non detergent oil.

If you're talking about COMP's red s**t with the viscosity of vinegar, then that could be (part of) your problem.

That stuff should be called COMP Re-re-re-re-assembly lube, because that's what it will cause.

I hope that you didn't FOD (foreign object damage) the engine out with all the (possible) iron filings from the wiped cam.

Also, I'm not a big fan of high volume high pressure pumps. What usually happens is they pump all the oil to the top of the engine which then starves the oiling system = beaing and (possibly) cam failures. But that's me.

Here's how I adjust a cam from the get go to final adjustment:

1) I follow that the cam mfg. says for initial and final valve spring pressures. MOST cam mfg. say to leave out such & such spring or install such & such valve spring for initial cam break in.

2) For hydraulic flat tappet cams, I put the #1 piston on TDC and adjust the lifters to 1/4 or 1/2 turn maximum by slowly turning the adjusting nut till there is hardly any slack in the valve train, then putting the 1/4 or 1/2 preload on the valve train. I then turn the crank 1/4 turn (90 degrees) and adjust #8. I rotate the engine another 90 for each cylinder (1,8,4,3 6,5. 7, and 2) and go through them again just to double check them. I can use this method because when I degreed the cam in, I mark the harmonic balancer at 90 degree incriments (90, 180, and 270) with a center or auto center punch.

3) Immeniatley after starting the engine and getting it tuned (timing done), I re-adjust all of the lifters to 1/2 turn. The proceedure that I use is one that I learned from the OLD Motors manual and my 64 Chevy II Helm manual: with the engine at idle, slowly back the adjuster nut off till the rocker arm starts to click. SLOWLY tighten the rocker arm nut till it JUST stops ticking. STOP and wait ten seconds for it to stablize. SLOWLY adjust the rocker arm nut 1/4 turn. STOP and wait ten seconds for it to stablize. SLOWLY adjust the rocker arm nut another 1/4 turn for a total of 1/2 turn.

I use my Adjust-A-Cover to do this as it never makes a mess and it makes accessing the rocker arms to adjust them a breeze. Search this web site to see how to get one.

According to Jeg's, the 911-16 springs are:

Seat load: 122lbs @1.900"
Open load: 309lbs @1.400"
Coil bind: 1.200"
Rate: 373lbs/in

And the Magnum 280H is rated to 6000 RPM, 122lbs of seat load makes break-in difficult and 309lbs is excessive nose load in my opinion. Unless you are putting it in a boat and holding it at 6000 RPM all day, I would use a different spring.

If you want to run a heavy spring like the one they recommend, break in the engine with a set of lighter springs, then change over to the 911s.

Man, that stinks. I feel for you. The 911's are pretty mild springs... the small block equivalent uses 109lbs on the seat. Long story, short, that low spring force shouldn't create enough pressure to wipe out a lobe. Sounds like a bad core... or Comp is working overtime to promote their cam-nitriding option. Or the oil just stunk. Many of the newer formulations are inadequate for flat tappets.

If you're dead set on the 280H (a nice cam IMO), try a quart of ZDDP and the remainder in Shell Rotella T3 (triple protection). Having Comp provide you with a nitrided cam would be smart extra insurance too. Quite frankly, Shell is the only company I trust to get it right with oil anymore.

If all else fails, go Crower. Never had 30 seconds of trouble with any of their products in 25 years.

Man, that stinks. I feel for you. The 911's are pretty mild springs... the small block equivalent uses 109lbs on the seat. Long story, short, that low spring force shouldn't create enough pressure to wipe out a lobe. Sounds like a bad core... or Comp is working overtime to promote their cam-nitriding option. Or the oil just stunk. Many of the newer formulations are inadequate for flat tappets.

If you're dead set on the 280H (a nice cam IMO), try a quart of ZDDP and the remainder in Shell Rotella T3 (triple protection). Having Comp provide you with a nitrided cam would be smart extra insurance too. Quite frankly, Shell is the only company I trust to get it right with oil anymore.

If all else fails, go Crower. Never had 30 seconds of trouble with any of their products in 25 years.
I too am glad I went w/Crower

I prefer to use Isky and Crower cams for a high-performance engine. I've used Comp Cams, Edelbrock, and Crane (when they were still in business) with decent success too.

As for installing a cam, once I have it degreed in, I coat all of the lifters and cam lobes with Isky cam lube which is molybdenum sulfide. I swear by it as I've never lost a cam due it going round on me.

I prefer to use Isky and Crower cams for a high-performance engine. I've used Comp Cams, Edelbrock, and Crane (when they were still in business) with decent success too.

As for installing a cam, once I have it degreed in, I coat all of the lifters and cam lobes with Isky cam lube which is molybdenum sulfide. I swear by it as I've never lost a cam due it going round on me.

Definitely. My buddies used to harass me for not using 'the recommended lube' from Comp, et al. Bah. Moly-D all the way. I'd rather have way too much lubricity for break-in, than too little. Without the moly and zinc compounds, a flat tappet is doomed.

According to Jeg's, the 911-16 springs are:

Seat load: 122lbs @1.900"
Open load: 309lbs @1.400"
Coil bind: 1.200"
Rate: 373lbs/in

And the Magnum 280H is rated to 6000 RPM, 122lbs of seat load makes break-in difficult and 309lbs is excessive nose load in my opinion. Unless you are putting it in a boat and holding it at 6000 RPM all day, I would use a different spring.

If you want to run a heavy spring like the one they recommend, break in the engine with a set of lighter springs, then change over to the 911s.


See that is what i was wondering. I chose the comp magnum 280h and by dumb luck found out it was the same cam that was in my dads 427. He just rebuilt it and the springs that he had on it weren't much stronger than stock. That cam is from the 80s but should there be that much of a difference in the springs? I do have a brand new set of springs that rate at about 90 lbs of seat load.

Sounds like someone should start selling 1.2 break in rockers. Make'em cheap and start making a killing. My circle track buds sware by these.

It doesn't surprise me and I don't believe it's isolated to Comp Cams at all or that it's the lube used on the cam.

I think it's an across the board issue with the metal used or the heat treat of the cam/lifters.

We no longer build BBC's with flat tappet cams at my shop.

It doesn't surprise me and I don't believe it's isolated to Comp Cams at all or that it's the lube used on the cam.

I think it's an across the board issue with the metal used or the heat treat of the cam/lifters.

We no longer build BBC's with flat tappet cams at my shop.

I broke-in my cam with my springs that had 43,000 mi and rocker arms that had over 100,000 mi. Then changed the oil/filter and refilled with JG BR oil again for a few hundred miles before I swapped the springs. Then a couple months later I swapped in Comp roller tip rockers.
When and if this engine lets go then I'm going full roller and saying good-bye to ZDDP forever.

We no longer build BBC's with flat tappet cams at my shop.

I take it the break-in nightmares have gotten old and you'd rather not deal with angry customers.

I take it the break-in nightmares have gotten old and you'd rather not deal with angry customers.

The failure rate is simply too high, why start with something that is a 50% or greater risk of failure.
3 flat tappet failures in BBC's in a year with everything done properly, 2 of those three being very mild old school grinds, one being a moderately aggressive older design. In other words all proven reliable lobes.
All this is after 20 years of engine building, being ASE master tech and engine machinist, aware of the current oil problems, and taking proper precautions.

Something has changed with either the:
Cam cores or material
lifter material

I check the lifter machining pretty closely, the cams taper I don't have a good way to really accurately check but when you have multiple lobe failures it's likely not poor machining of one lobe due to worn grinder, etc.

We're getting shyt materials is my theory but at this point it doesn't matter, all BBC's get a roller, and we will probably replace most SBC applications with an LSx engine.

The failure rate is simply too high, why start with something that is a 50% or greater risk of failure.


Don't rollers fail too? It would seem that you have a chance of failure with either type of cam if the product has no QC.

2 things, buy a moroso valve spring pressure tester, for use on assembled engines, and see what you real on YOUR engines seat pressure is at full open, I bet it's way to high! Second check you valve spring coil bind clearance at max lift .050 or more is good, in the YOUR situation you described it will be one or the other or both, from what you described that cam was loosing material instantly on fire up, heck I've witnessed em cranked w no oil and not wipe that fast!

Comp even tells it's customers to use Cranes 99002-1 assembly lube.

Don't rollers fail too? It would seem that you have a chance of failure with either type of cam if the product has no QC.

True, but probably less since everyone is going roller these days and you don't need to sit in the driveway for 30 min reving between 2000-3000 rpm. You just prime, start and go for a drive with any shelf oil.

See that is what i was wondering. I chose the comp magnum 280h and by dumb luck found out it was the same cam that was in my dads 427. He just rebuilt it and the springs that he had on it weren't much stronger than stock. That cam is from the 80s but should there be that much of a difference in the springs? I do have a brand new set of springs that rate at about 90 lbs of seat load.

90 lbs of seat load is fine for a cam like the 280H in a street driven engine. Hydraulic flat tappets don't like lots of seat load, mechanical flat tappet will tolerate the higher load much better.

90 lbs of seat load and somewhere around 270 lbs of nose load will work just fine with this cam and help it live longer. Like Jake said, the best bet is to go roller, especially since we are stuck with motor oils that don't have ZDDP unless you add it or run a diesel oil, and the sensitivity to factors like lifter crown radius and lobe taper.

Most roller cams also seem to "require" godzilla spring loads that really aren't necessary for most applications.

Here is an update. I called Comp today and spent a good amount of time trying to see what they would be willing to do. It wasn't much and seemed like a hassle that really wasn't worth going through the trouble to get a cam that will most likely fail again. They blamed the oil and bbcs in general and even said that they are getting the hardened cams back.


So I have decided to look into another cam. At this point I can't afford a roller set up. The machine shop recommended Erson cams but I cant find anything online and im not sure if they are still in business or who owns them.

I think i have decided to go with Crower. Any one know of a Crower cam that would be comparable to the Comp 280H Magnum for a BBC?

You might want to re-think it a bit.

There is nothing wrong with Crower, Isky, Bullet, Erson, Elgin, etc, etc.

They are ALL getting cores from the same suppliers, so if the metal is an issue or the heat treat is an issue, it will affect all of them.
Changing brands is not a magical fix.

Comp isn't my favorite brand for camshafts but they aren't necessarily responsible for the root cause of the failure.

There are only a couple of core suppliers and they supply the entire industry.

So good luck with your BBC flat-tappet trials and tribulations.

Alright, if you're staying flat-tappet, and going Crower, there are a few things to note. Their off-the-shelf cams are typically split pattern (different intake/exhaust durations, lifts), so there's no directly comparable cam to the 280H.

For a healthy, medium lopey idle and good power in a 402 BBC use Crower #01205. It's 220/232@0.050" and .529/.527 lift with the 1.7:1 rockers. The 280H is a full 10 degrees bigger on the intake... but don't be fooled by the comparison. The Crower is ground on a 108 LCA vs. Comp's 110, and achieves slightly greater intake lift with that smaller 220 intake duration. That, along with the slightly longer exhaust duration will net you the same or better power band than the 280H and slightly better low-end driveability.

Use their 'Cam Saver' lifters. They have a tiny flat milled down the length of each lifter that allows a measured amount of oil down onto the lobes for extra protection.

Crower's break-in procedure is NOT the norm, so follow it closely. If you have any doubts, call their tech guys and they'll talk you through:

1) no oil galley restrictors
2) break-in with low-tension break-in springs, 225#-250# max. OPEN force
-not seat force-
3) run engine for 35-45 minutes, varying RPM between 2000 and 3000.
4) recommend using Crower Engine Oil Supplement (EOS) #86084 or equivalent. If you're curious what those 'equivalents' are, call and ask. Not the time to get shy. :)

5) use only 10w-30 for break-in. cold flow is critical and thicker oils will not flow well cold.
6) do NOT use synthetics during break-in

The cam will come with an installation booklet that describes all of this in detail.

And like Jake said... none of the above is a magical fix. It is just the best set of procedures Crower has developed. I am building a small block with a Crower flat solid in the near future so I'll be following the same procedure with my own hard-earned $$$ just like you.

I'll say a few prayers for the both of us. :)

For a healthy, medium lopey idle and good power in a 402 BBC use Crower #01205. It's 220/232@0.050" and .529/.527 lift with the 1.7:1 rockers. The 280H is a full 10 degrees bigger on the intake... but don't be fooled by the comparison. The Crower is ground on a 108 LCA vs. Comp's 110, and achieves slightly greater intake lift with that smaller 220 intake duration. That, along with the slightly longer exhaust duration will net you the same or better power band than the 280H and slightly better low-end driveability.




I was looking at the #01205. I was also looking at the #01101. What do you think of that cam? I am thinking about that one because it requires much less spring pressure. That one requires 80/90 lbs of seat load and only 275lbs open. My thinking is that it may be safer in the long run as far as durability because of the smaller amount of pressure. Thoughts?

*Update*

After speaking with Crower, I have figured out the next plan of attack. I am going to go with with Cam 01101 278H.

Hear are the specs.
Intake Duration: 278 Intake Lift: .515
Exhaust Duration: 284 Exhaust Lift: .530

Lobe seperation: 112


The people at Crower were really helpful. They said I can use lighter stock type springs, the motor just cant be held at high RPMs for long period of time. Which I believe CAMDOC said here.

This is a case where I have to build it the way I am going to drive it. The car has a 700r4 transmission and I am convinced that lowering the spring pressure will not only help prevent issues on break in but help the cam as far as durability goes.

*Update*

After speaking with Crower, I have figured out the next plan of attack. I am going to go with with Cam 01101 278H.

Hear are the specs.
Intake Duration: 278 Intake Lift: .515
Exhaust Duration: 284 Exhaust Lift: .530

Lobe seperation: 112


The people at Crower were really helpful. They said I can use lighter stock type springs, the motor just cant be held at high RPMs for long period of time. Which I believe CAMDOC said here.

This is a case where I have to build it the way I am going to drive it. The car has a 700r4 transmission and I am convinced that lowering the spring pressure will not only help prevent issues on break in but help the cam as far as durability goes.

That's a nice cam. You'll enjoy it. What did the tech say about the break-in procedure? The open pressure for the springs on that cam should be between 275 and 285 pounds. According to their own catalog, that's too much for break-in. If he didn't mention it. Call and ask.