Motor Guru's
 

Hi all,
We are in the process of freshening my modified ProCharged 454 Mag. Upon diasassembly inspection about the only real issue after4 years and about 180 hours (some hard) is that the Cometic head gasgets failed between the cylinders all of them. We made so many drive changes (1.50 to 1.35 to B-Max 1.30) and prop changes we knew that it fell off a bit but could not put a finger on the exact cause (I guess we now know why). It still ran hard up to 86 MPH in a 280 Velocity at tear down. What are your thoughts of O-ringing it, using the Cometics again, we will be using the Edelbrock aluminum marine heads this year?

I've never heard of a Cometic acting that way. Almost seems as if the head was lifting up. Ever retorque the heads?

The cometic head gasket is a great gasket the Felpro MLS has a better sealing ring design I run the MLS in everything performance we build you shouldn't need to oring the block . We've taken all of our racing engines that had orings and removed them using exclusively the MLS and havent had a problem from our outlaw and pro import engine making 65 lbs of boost to the 1000-1200 marine poker run engines . If you get the tune up right with the fuel press timing and boost and O2 dead on you will not have any issues. Check and make sure the exhaust valves are sealing correctly and the guides have the correct clearance because they wear severely in that application. Hope this helps SIncerely Laz Mesa
P.S. Use a good quality exhaust valve
www.mesabalancing.com

Are you using head studs ?? If not that will help with the head lifting problem. Also have deck and heads checked for straightness.

r,
The other thing to look at is the surface finish on the heads and block. The MLS gaskets require a much smoother and flatter finish than composition type gaskets. Not all surfacing equipment is capable of doing the correct job.

Also, were the heads retorqued at any time. I have been waiting about an hour after torquing the heads initially, then going back and loosening one bolt at a time and immediately retorquing it to the full torque. A lot of guys just put a torque wrench on the bolt or stud and pull on it to "retorque" but 99% of the time this does absolutely nothing due to the fact that the amount of torque needed to just get the bolt or nut moving again (breakaway torque) is much more than the final torque desired.

We have been using the MLS gaskets, both Cometic and Fel Pro and really have had no failures that I am aware of.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

They are studed but no we did not re torque

Everything else looked great. The springs are tired but valves, etc,. are like new. We had a problem with the FelPro which led us to Cometic this motor was 4 years on the build with close to 200 hours.

Smitty, Everything was true and yes it was studded.

I would kill to get that much time out of a procharged engine! I actually got close to that this time around.

Oil changes at the first sign of consumption usually about 7 hours. Cheep insurance. 50W Valvoline racing oil and no thermostat we use the crossover. Water temps never get over 110. I would not have gotten any more time then I did. I new it had to be freshened.