Ever see a blown H.G. look like this? (pic)

[Pablo]

noticed some coolant in the oil so I pulled the heads. Drivers side gasket looks brand new, passenger side is what you see above. I'm not sure what to make of it, the fire ring seems fine and it doesn't look like combustion gases were making it past there. The plugs, pistons, and cyl heads in those cyl's don't look like they saw any serious detonation either.

Any thoughts on what caused this?

The last (and only) hg that I've blown looked like the standard blown out fire ring. Though I'm 99% certain this is the problem, theres even a little doubt that this is where my coolant came from. I'm wondering if when I lifted the heads up the gasket tore and dropped off crumbs of the gasket that I didn't notice.

Does it look like a blown HG to you?

 

[Ed Valvo]

Head lifted. Fire ring is still there however gasket material is blown out leaving the metal core. Mine did this. Car was drivable, just could not go into boost without the coolant bottle bubbling up.

 

[ttypewe4jim]

What brand gasket are they? I cant really tell from the picture...

 

[Pablo]

felpro, should have gone cometic....lesson learned

 

[ttypewe4jim]

felpro, should have gone cometic....lesson learned

Thats what I figured it was... I wouldnt blame the tune to much yet... I know recently alot of people have had trouble with the felpro gaskets blowing way to easly Pauly pacecarta has made some post on it over on tbs.com. Cometics are the way to go though if you can get them to seal

 

[BEATAV8]

try cometics but check the flatness of the deck and heads with a straight edge and a feeler gauge first. Gotta be flat for a steel shim gasket to work properly. If a .002" feeler will fit under the straight edge anywhere then some machining will be required.

 

[forcedfedv6]

felpro, should have gone cometic....lesson learned

Pablo I told you so, but you Did Not listen. LMAO, I had the same thing happen to me, not once but twice, been there done that with felpro gaskets., I have cometics now and after a few passes heads lifted to where you could hear the exhaust compression coming out of both cylinders 3 and 4 but because i had cometics all i did was retorque, if this would have been felpro gaskets, a headgaskets replacement would have been in order, just make sure that after your cometic install, you retorque the heads to torque values, I found out that my heads studs streched so much that I must have been running about 60psi on the heads bolts causing the cylinder pressure to leak at about 15psi, like I mentioned above, I just retorqued and problem was solved..

 

[ttypewe4jim]

Pablo I told you so, but you Did Not listen. LMAO, I had the same thing happen to me, not once but twice, been there done that with felpro gaskets., I have cometics now and after a few passes heads lifted to where you could hear the exhaust compression coming out of both cylinders 3 and 4 but because i had cometics all i did was retorque, if this would have been felpro gaskets, a headgaskets replacement would have been in order, just make sure that after your cometic install, you retorque the heads to torque values, I found out that my heads studs streched so much that I must have been running about 60psi on the heads bolts causing the cylinder pressure to leak at about 15psi, like I mentioned above, I just retorqued and problem was solved..

You are lifting the heads at 15psi? Ive never seen that before... what did you do replace the studs? or jsut torque them more?

 

[norbs]

Those gaskets look like they are for a N/A motor, normal stuff. On a stock block go with the RJC stainless shim gasket set or cometics. I;m suprised you got 15 psi out of them....

 

[bison]

Those gaskets look like they are for a N/A motor, normal stuff. On a stock block go with the RJC stainless shim gasket set or cometics. I;m suprised you got 15 psi out of them....

They are fel pro 9441. ive gone 123-124 on them no problem back in the late 90's

 

[Pablo]

Pablo I told you so, but you Did Not listen. LMAO, I had the same thing happen to me, not once but twice, been there done that with felpro gaskets., I have cometics now and after a few passes heads lifted to where you could hear the exhaust compression coming out of both cylinders 3 and 4 but because i had cometics all i did was retorque, if this would have been felpro gaskets, a headgaskets replacement would have been in order, just make sure that after your cometic install, you retorque the heads to torque values, I found out that my heads studs streched so much that I must have been running about 60psi on the heads bolts causing the cylinder pressure to leak at about 15psi, like I mentioned above, I just retorqued and problem was solved..

Haha :biggrin: yeah, you got me. I did say that I sometimes need to learn the hard way though.

What are you torquing your head studs to?
I was gonna try to throw the cometics on there with some copper spray to avoid having the block deck machined for them, have you done that?

 

[Super6]

my fel-pro 9441 done the samething...just too much cylinder pressure. i sprayed copper coat on some cometics and have not look back. my short block has never been out of the car and i have no leaks at all with the cometics.......Bob

 

[twin 93 svt]

seen plenty times

 

[turbofrank]

Pablo have you checked tork wrench calibration ?

 

[forcedfedv6]

You are lifting the heads at 15psi? Ive never seen that before... what did you do replace the studs? or jsut torque them more?

No the boost was set at 21 psi, but after it started making noise it would not go past 15 psi before the heads started leaking compression out the sides on cylinder 3 and 4, I retorqued and it fixed the problem.

 

[forcedfedv6]

Haha :biggrin: yeah, you got me. I did say that I sometimes need to learn the hard way though.

What are you torquing your head studs to?
I was gonna try to throw the cometics on there with some copper spray to avoid having the block deck machined for them, have you done that?

Pablo throw on the cometics, just make sure the surface of the block and heads are smooth at least .50 finish, throw some copper spray on the gaskets and torque them to 80psi, after a few runs and heat cycles, go back and retorque to 85psi and ur done, dont forget to throw in at least 3 GM sealing tablets to make sure you wont have any leaks and run water at 1st then change up to antifreeze after the retorque., I am running 21psi and constant beating up on the car and so far so good no leaks or heads lifting. good luck.