i have a 350 in my 77 camaro that runs strong but has a crack out side of the block on the driver side about an inch below the head. there is only water leaking out side block . i bought this car like this thinking it was only a freeze plug popped from sitting over the winter time. is it worth trying to weld the crack shut to see if it will hold up? my buddy has the welding equipment capable of doing this. i was just wondering what everyone thinks on this. thanks

I have seen them welded and hold up good. You will want to take and drill a hole at both ends of the crack to prevent it from spreading. Somebody else should chime in on what type of welder to use.

we are gonna use a stick welder with a nichol rod for welding cast. hope fully this will work

You really should preheat it before welding and then control the temperature drop afterward.

Yup! hi-nickel for cast... should be fine if the guy driving the stick is any good. My only concern would be how it got cracked in the first place.... what caused it? Do ya know?

im guessing it froze up during winter. the car was parked for a couple of years. the guy said he thought it just popped a freeze plug. lol i wish. my friend welds at his job on a daily basis. he also said something about heating it up. i hope it works. also are 882 cating heads any good? they are 74 models.

Makes me nervous... I might be inclined to look deeper for more damage. Multiple freezes hard enough to crack it would scare the pooky outta me.

just my 2 cents worth...

i have a 350 in my 77 camaro that runs strong but has a crack out side of the block on the driver side about an inch below the head. there is only water leaking out side block . i bought this car like this thinking it was only a freeze plug popped from sitting over the winter time. is it worth trying to weld the crack shut to see if it will hold up? my buddy has the welding equipment capable of doing this. i was just wondering what everyone thinks on this. thanks

Yes, it can be welded with the proper rod and pre-heating it, while controlling the cool down, but you have another issue.... Since it's an inch away from the head, count on toasting the gasket, and a possiblity of a deviation of the deck surface.

I had a "379" 4bolt 350 that cracked in the same place on both sides about 1 1 1/2 below the deck. It wasnt geting any water in the oil but I yanked it anyway wanting another build anyway.
And boy let me tell you this thing wasnt just cracked on the outside it was split down both sides on the inside and up into and thrue the deck surface how it didnt cross fluids is beyond me but it didnt. Yours may or maynot be this bad. but what the hey weld it up and let her go and see what happends.

Matt

i'm thinking maybe i might start looking for a good short block or a complete big block to put in it. i have to pull it out any way to get to it to weld it so i might just pull the heads and all to use on a 74 vette 350 block i have from a nother long gone project.:rolleyes:

Heck, clean it up good w/ some Brakeclean and slap on a big daub of good old JBWeld!!

And I'd use a lower pressured rad. cap too.

pdq67

yeah heck try the JB worth a shot..if not snatch it out check for the places I talked about if it looks ok every were but you said take it and weld it up and keep it or re-use it. I was really PO with mine when I checked the cylenders they had virtualy no wear maybe half a thousands.

But hey live and learn I took the front bolt out that went into the water jacket lost alot of fluid working on the moroso cheap a$$ alternator bracket days then weeks(wont driving car at all) went by I forgot about the fluid loss then Bam too late!

O well the 6inch rod 383 scat kit and the AFR heads are waiting on the block

Matt

years ago, had a 68 Firebird...350/350...had a cracked block...used jb weld and that radiator/block sealer stuff...eventually put a 455 in it...but motor ran fine without leaking up to that time.

Consult your local machine shop to see if they can stitch pin it. That way you avoid the heat/warpage issues.

tgw's on to something!

I forgot about using them..

Sorry..

My bad..

pdq67

I have a 2-bolt main 350 block that has been vatted and magnafluxed.... new freeze plugs, cam bearings, and honed cylinders... don't know the bore diameter, but I can measure it when I get a chance. Some surface rust from storage for the last 10 yrs, nothing major though.

It is yours if you want to come and get it..... I am located in Stafford, VA. About 30 miles south of Wash, DC. I will go check casting numbers and report back if you want.

what is stitch pinning? never heard of that before

what is stitch pinning? never heard of that before

It's where a hole is drilled out on the crackline, then threaded & a cast plug is inserted. Then another hole is drilled on the crackline, then threaded and a cast plug is inserted.... and so on.... until the entire length of the crack is covered by overlapped drilled & plugged holes.

BTW - 882 heads are decent. They're smog era heads but still can be ported to be respectable.

As far as the block crack.. good luck!

I had a 350 that set outside in the frame for the winter while waiting for a new dog house to replace the wrecked one. Had no raidiator so never thought about the water that might still have been in the block. What a surprise when it started leaking after it was all back together. Thought it was a freeze plug as well only to find out it was cracked all along the top edge of the block. After taking it out and tearing it apart I found it was cracked inside as well. Unless you are really hard up for the cash and you love doing the labor, I'd chuck it. Don't know what your ultimate goal is but if a driver is all you need you should be able to pick up a used engine cheap. Look for one that is still in a car so you can here it run. Try your local paper before you resort to the trading post. I have went to look at someone else heap that read first 200 bucks and was almost paid to just get it out of their yard lol. If your lucky and you get the whole car, you can sometimes sell off the stough you don't need to make back your money. Just can't belive it would be worth your time for what it would proably cost you to get an replacement.

it's official. the block is cracked real bad now that i got it out and looked it over today. lol:screwup: what a waste lol thinking about 454 this time dont know hard to find one cheap and running.:bowtie:

Look in C/K 20 and 30 P/U's and old 'Burbs..

pdq67

Welcome to the dark side... the force is strong;)

Got mine from a burb I retired..

Had our 292 (.060" over 283) stitch pinned on both sides of the block by the pan rail. The machine shop that did it first hyro (filled the bare block with blockoff plates on everything) with waterpressure tested it to 25 psi to find all the leaks plus magnifluxed it to double check. They then pin stitched all the cracks and re-hydro pressure tested it. It cost $250 including honing the cylinders.

http://i114.photobucket.com/albums/n260/Cardinal_03/87%20S10%20Drag%20Truck/SparkplugwiresPS.jpg

my friends dad has a 454 bored 30 over he just took out of his chevy dually. he put a 350 in its place because he hated only getting 7 miles to the gallon. lol
i am trying to talk him into selling it to me to put in my 350's place plenty of torque to make it haul ass lol :happy: :smokin:

Clean it up with a wire brush and brake cleaner, and then JB weld it.

We did this as a temporary repair to the freeze cracked 350 (same place - an inch below the deck) in my friends 78' z28 and its still holding strong. He is building another motor but driving it until this one gives up. Its been on there for 3 years now.

Just interesting trivia; they're not really even "freeze plugs" but "core plugs". They're used to support the green sand core that forms the block cooling passages (which you probably knew anyway) and to remove the sand after the casting process is complete.

Since the plugs are concaved, they tend to to grip tighter when there is pressure behind them rather than release. GM didn't realy expect them to come loose when water freezes, but it's certainly nice if/when they do- but they don't usually release. I sure wish I could remember where I read this.

yea if they would have popped out i would have a good 010 block:whine:

Just interesting trivia; they're not really even "freeze plugs" but "core plugs". They're used to support the green sand core that forms the block cooling passages (which you probably knew anyway) and to remove the sand after the casting process is complete.

Since the plugs are concaved, they tend to to grip tighter when there is pressure behind them rather than release. GM didn't realy expect them to come loose when water freezes, but it's certainly nice if/when they do- but they don't usually release. I sure wish I could remember where I read this.


Sorry, but you have been misinformed. I work at the GM foundry in Ohio.

The jacket core is suspended by the joint face core with screws. The freeze plug holes are actually called welch plug holes. The "welch plug" was invented by the Welch brothers motor car company, which was eventually bought out by GM. Today, welch plugs are used for many things, not just for a water barrier. But they were not engineered for core package assembly, nor is the water jacket core a "green sand" core. "Green sand" is a special process, not just a composition for a water jacket. Juast like "precision sand." We use the typical clean beach sand to form the core, then dipped in a special baume' to seal the core and to help prevent burn in sand as well as veining. Some baume' is tan, some blue.

Although the plug holes are helpful during shot blasting to allow the steel shot to run out of the water passages faster, they aren't of any major benefit for sand shakeout. We use huge shaker oscillators that bounce the block severely, and bangs out all of the residual sand. Today, we achieve the same shakeout result with 90% of the blocks not having any welch plug holes.

D-max and the 4.3 is the only one with welch holes as of now, as well as the 3.8 (#793) block & (#134 & 781)head. The 60 degree V6 lost the welch plug hole about 4 years ago, when the 089 and 253 block numbers merged to the 641 block. The 089 and 253 blocks only had one welch plug hole on the right side. Proving again that the water jacket core is suspended by the joint face since there is no welch plug hole on the left side of those blocks.

The revised 2007 4.3 (#234) has an extra welch plug hole at the bottom of the jacket area. Once again, this is not a fastening area for cores, it is a functional area for freeze plugs. The old 4.3 (#090M) is being phased out right now.

I will see if I can get permission to take photos of the core packages to show you that the welch plug holes have nothing to do with core assembly.

OK, it's not the first time I've had bad information. Thank you for posting and setting me/us straight! Can't believe everything you read I guess...

Any idea if this was true back when the smallblock was designed back in the 50's? Just curious...

I'd love to see your pictures!

OK, it's not the first time I've had bad information. Thank you for posting and setting me/us straight! Can't believe everything you read I guess...

Any idea if this was true back when the smallblock was designed back in the 50's? Just curious...

I'd love to see your pictures!

The welch plug holes were always for block preservation. It allows freeze protection as well as flexibility. (which is why serious racers tap these holes and insert steel plugs into them... to tighten the block against flexibility)

In the meantime, I will show you these photos.. You will see how thin-walled the castings are nowadays, just to save weight for EPA/CAFE standards.

http://members.aol.com/justbugg/bbcast.jpg
BIG BLOCK


http://members.aol.com/justbugg/sbcast.jpg
4.3 BLOCK (look at the thin wall cylinders)


http://members.aol.com/justbugg/headcast.jpg
4.3 HEAD

I've built too many small block Chevy's to try to count but I do remember the different eras of blocks and how they changed.

265/283/327 blocks: harder than a prostitues heart. Cylinder head area of the block was thicker than 5/8".

307/350/400 blocks: not as hard and barely 1/2" thick on the cylinder head area.

Later 350/262/267/305 blocks: soft as a baby's hinnie and barely 7/16" thick. HAVE to sonic the block to IF it can be bored.