Cracked Blocked

I've been chasing a blown head gaskets for a while now. I'd change it out only to have it blow again after a few runs.

I put my car in a speed-shop to have both gaskets replaced. Found out that my block was cracked - in two places - between the water jacket and head bolt on #'s 2 and 3 cylinders.

FWIW, I've used studs since the motor was built (302 b/s to 347).

I guess I over-torqued the heads at some time. The mechanic who found the problem noticed it when he was "block-sanding" the face. I probably would've never noticed it (along with possibly 3 paid mechanics who didn't see the cracks).

As, "time is of the essence", I'm looking at a 302 roller block to throw in and shoot the nitrous to it. I'll work on finding a forged block in the meantime.

Snot happens.

 

Good find...

...RFF...:Handshake

 

Wow, you did that from Singapore?

 

A man of my misfortune has few limitations.

 

Well, if you were closer I'd give you a 93 roller short block.

 

I'm closer than he is come on down!!

Sad to see that Rick... but now you know.

 

Sorry to hear this. Good time to bring up for others, studs get finger tight installed in block, assemble, then torque nut to spec.

How did the rest of engine look on wear or you waiting on new block to tear down?

 

sorry to hear that....good job by your mechanic!

 

So, how much over-torque did it take to crack this?

Are we talking 2-5 ft/lbs, or more like 20-30?

 

He hasn't gone into the engine yet, but I'll keep this thread updated with findings.

FWIW, the car would run/rev without definitive tale-tale sounds. Water was seeping out between the head and block though.

 

How does one help prevent it? Is this why people use "block filler"? I'm just asking cause I don't know...

 

Thanks, D. I've spotted a low-mileage 302 roller block for $350. I'll throw it in there and add a touch of spray for the fun factor.

I'm also looking into a R block (assuming all the forged rotating assembly is in good shape).

 

Dunno, Scott. Normally, I torqued them to 100 ft lbs. I do recall going to 110 once - but that was after a gasket had already blown at 100 ft lbs of torque (correct sequence of torquing, lubricant, etc).

I can't pinpoint exactly when this might've occurred. It's kinda moot now.

 

Glad you found it. I've got to tear mine down this week and try to find my problem. I guess I'll fire the engine builder.

 

Block Filler is a great topic to bring up during a Jackstand Racing event.

Like Main Stud Girldles, some gearheads say . Some say . Me? I say .

But, yes, the idea of the filler is to help strengthen the block.