Leaking head gasket


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By carl - 17 Years Ago
I filled the engine up with coolent the othey day and i had a leak on the drivers side head.the engine has had a valve job, heads milled .025.when i assembled the engine i torqued them once to #75 .after the leak showed up i retorqued to #90 it slowed down but still leaked some.i took the heads off and checked for flatness and they are ok.i miked the gasket as the hoosier man suggested.the fire ring was .o52 and the outer part of the gasket is .045.so it looks like the ring isnt compressing enough.the head bolts arnt bottoming out and the guide pins have enough clearance,also the two long bolts are in the outer holes.i talked to john murmmert about the gaskets and he said they havent had a problem with best gaskets.he will probably replace them but i am a little leary about trying them again.has anyone else had this problem ,i have thought about using fel pro gaskets.any advice would be greatly appreciated  Carl   ohio 
By 55Birdman - 17 Years Ago
Fel-Pro is the way to go . I haven't had that problem but if they leaked once I dont use that brand gaskets again. Just one of the quirks I have .
By Ted - 17 Years Ago
Are you sure it’s the head gaskets leaking?.  The early heads do not have blind holes at the threaded holes for the intake manifold studs and are known to seep at those particular threads if sealer is not used on them.  It’s such a small seep that it can look like a head gasket leak by the time it works its way to the back and down.
By carl - 17 Years Ago
Yes i used sealer on those threads on the intake.my concern is the difference in the thickness of fire ring and the outer part of the gasket..006 seems like a lot .the engine has never been started yet so the leak showed up with no pressure on the system   Carl
By Ted - 17 Years Ago
I find where the fire rings tend to uncompress slightly when the head gaskets are loosened so I'm not sure that you can consider the uncompressed thickness a valid value.  I've come across leakage issues with both brands of gaskets but the Best Gaskets appear to be more robust than the FelPro when it comes to detonation.  Are you using grade eight bolts?  The original early bolts are notorious for stretching.
By Ted - 17 Years Ago
I'll also suggest that you torque the heads in three steps and be sure that you torque starting in the middle and working outwards in a spiral pattern.
By speedpro56 - 17 Years Ago
Carl, Like Ted said if the bolts are the old ones, go buy new grade 8s then start in the middle and work your way out to the outer edge. Start out with 40 lbs work your way completely thru, then 65 lbs thru, then 75 thru, and I go up to 80 lds on the last pass and that should do it. I'm using Best Gaskets and there doing great, actually sealed mine better than fel-pro.
By carl - 17 Years Ago
Yes i did use the old orig. bolts,  so i guess the best thing is to buy new grade 8 like you suggest.i said that i torqued them to 75# once but i did go through the sequence like the service manual says.murmmert is sending me some new gaskets and he suggested using copper sealant.i think the reason is i told him that the heads were milled with a rotory cutter and they are not completly smooth.i also bought fel pro gaskets so i will compare them with the best gaskets.  thanks for the advice.  Carl
By suede57ford - 17 Years Ago
Felpro's can hang into the cylinder of a 312 after compressed on a 312 +30. This causes the folded steel ring to melt if abused.  Every motor I have pulled apart with Felpro's had some sign's of places that were ethier melted or detirorated and would eventually or already had caused a water leak.  I used victors a bunch and they were a better a more durable gasket than the Felpro's. 

The latest versions of the Best brand head gaskets were big enough diameter even after compressing them and had no signs of deterioration around the water holes as the Felpro's always seemed to. 

I use ARP studs which allows me to torque them much higher than stock.  I have increased the torque by 15+ pounds and have not had any head gasket failures lately. 

I will use the overtorqued ARP's and Best Gaskets in the next one I do.

By carl - 17 Years Ago
ok i am going to use new grade 8 bolts,i want to drive the car not tear it down again.i tryed to find grade 8 bolts locally but cant so i guess murmmert is who to get them from.  Carl