Head gasket failure pics

vette427sbc

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I blew a head gasket during a track day a few months ago, and finally got around to pulling the head. This is the drivers side head. Why did this happen? Car ran at 195* water temps all day (temp sensor in pass head) and at times 240* oil temps.

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Warped head? Stretched head bolts? Wrong torque/retorque value? Bad/wrong head gasket? Pick one.
 
Sure looks like the head lifted on the middle 2 bores or was not torqued down properly. What torque sequence was used? I hope a spiral pattern from inside out??
 
I no expert, but I look at that, and yet again, those two center/top holes and are too close to the bore, and the bolts forced the sealing ring into the cylinder, opening it up to the water, thing that gets ME is.....even IF there is enough room, almost has to be, I would think, unless someone bored the living shit outta that block.....

but just for giggles, lets say the block is ok....so then the rong gaskets were used....those elongated holes in the gasket....I never seen THAT before....

something is FISHY.....:clobbered:
 
Sure looks like the head lifted on the middle 2 bores or was not torqued down properly. What torque sequence was used? I hope a spiral pattern from inside out??

Yep... Torqued as per AFR says IIRC it was start at 40 and work up to 65 ft lbs

Looks like the heads never got torqued properly also is the deck drilled in the center for the use of the 1003 gasket.

This apply to 350 blocks as well
http://www.chevyhiperformance.com/techarticles/90678_small_block_400_cooling_tricks/index.html

Who's heads are those??????????????????

AFR 180 heads, Felpro .039 gasket with the proper valve pockets. For all I know the deck is not drilled.


The car ran perfect for over a year before this happened... Although that track day was the hardest Ive ever pushed the motor.
 
Sure looks like the head lifted on the middle 2 bores or was not torqued down properly. What torque sequence was used? I hope a spiral pattern from inside out??

Yep... Torqued as per AFR says IIRC it was start at 40 and work up to 65 ft lbs

Looks like the heads never got torqued properly also is the deck drilled in the center for the use of the 1003 gasket.

This apply to 350 blocks as well
http://www.chevyhiperformance.com/techarticles/90678_small_block_400_cooling_tricks/index.html

Who's heads are those??????????????????

AFR 180 heads, Felpro .039 gasket with the proper valve pockets. For all I know the deck is not drilled.


The car ran perfect for over a year before this happened... Although that track day was the hardest Ive ever pushed the motor.

Looks to me like your combustion pressures (possibility of a little detonation with those mountains) caused some head lift and everything went south from there. could be a number of combined causes.

At the very least I would go back with ARP studs with molyd lube and some good gaskets, assuming everything else is up to snuff.
 
Have the heads checked for straightness, looks like it's warped

Were the heads installed on a fresh engine? If not, were the holes in the deck cleaned for accurate tq spec? I torque mine to 70 with arp bolts and moly on the shaft and washer, sealer on threads. Never had a failure even with temps up to 240.

Sent from my GT-I9000 using Tapatalk
 
Its hard to believe the head would warp that bad if not overheated. It's like there was almost no clamping force left on those middle cylinders. I suspect head bolt failure. Or they viberated their way loose. Did they break loose easy on the center cylinders? What kind of head bolts? I wouldn't reuse them.

You better bust off the other side. I bet it's creeping too.
 
Have the heads checked for straightness, looks like it's warped

Were the heads installed on a fresh engine? If not, were the holes in the deck cleaned for accurate tq spec? I torque mine to 70 with arp bolts and moly on the shaft and washer, sealer on threads. Never had a failure even with temps up to 240.

Sent from my GT-I9000 using Tapatalk

Yeah I had the shortblock done before I put the heads on. Not sure if the holes were cleaned...

Its hard to believe the head would warp that bad if not overheated. It's like there was almost no clamping force left on those middle cylinders. I suspect head bolt failure. Or they viberated their way loose. Did they break loose easy on the center cylinders? What kind of head bolts? I wouldn't reuse them.

You better bust off the other side. I bet it's creeping too.

Thats what Im thinking as well... I cheaped out and re-used the head bolts so maybe they did fail. I took the bolts out with an impact gun so I wouldnt have noticed if some were loose or not. Would have been nice to know though. The other side is coming off tomorrow night to make sure its not on its way out too.

Anyone have head studs on their vette? Can you still remove a head with the motor in the car?
 
I pulled the other head off last night... Same deal. Didnt leak, but it looks like it was on its way. Ill chalk this one up to installer error. I must have messed the torquing sequence up somehow. I did put this motor together at midnight right before my first ever trackday last year so I probably rushed it. :push:

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New head bolts, gaskets and a few more goodies on the way.

Was the block decked ???

Ill have to check the spec sheet to see if it was done during the rebuild. I dont think it was though.
 
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