cylinder pressure and gaskets/fasteners???

Posted By: psycho_440

cylinder pressure and gaskets/fasteners??? - 09/07/09 02:11 PM

all references i have ever read about head bolts, and gaskets use compression ratio as a guideline...but what about actual cylinder pressure??? now running arp bolts, felpro permatorque blue gaskets with 12.5 comp ratio. cranking cylinder pressure is around 220psi.dist is locked @ 37*. just burnt a gasket between #3 an #5. plan to go to a mls gasket with a set of studs, but just thought i would try to get some opinions. and it took alot of runs for the gasket to finally fail. any help would be great thanx!

Posted By: JohnRR

Re: cylinder pressure and gaskets/fasteners??? - 09/07/09 02:21 PM

Which gasket ? a race gasket or the 8519 ? I had an 8519 fail at 12.2, should have used something better

. Also alum heads or iron ? If alum I'd be using studs , especially with that compression.

Run a thread chaser in the block holes before installing the studs , hopefully ythe block didn't get damaged , a failure in that small area can burn thru the deck after the gasket fails.

Posted By: therocks

Re: cylinder pressure and gaskets/fasteners??? - 09/07/09 02:27 PM

I run 12.5 domes in the 440.It had the 09 felpros with the iron heads.Now it has their Marine gaskets with the aluminum heads and ARP bolts.No problems ever and the first set wan on for 8 years and the new set 2 years and its street driven.Rocky

Posted By: JohnRR

Re: cylinder pressure and gaskets/fasteners??? - 09/07/09 02:32 PM

Quote:

I run 12.5 domes in the 440.It had the 09 felpros with the iron heads.Now it has their Marine gaskets with the aluminum heads and ARP bolts.No problems ever and the first set wan on for 8 years and the new set 2 years and its street driven.Rocky

You obviously aren't making enough HP for the bolts to be a concern.

Posted By: psycho_440

Re: cylinder pressure and gaskets/fasteners??? - 09/07/09 02:36 PM

Quote:

Which gasket ? a race gasket or the 8519 ? I had an 8519 fail at 12.2, should have used something better . Also alum heads or iron ? If alum I'd be using studs , especially with that compression.

Run a thread chaser in the block holes before installing the studs , hopefully ythe block didn't get damaged , a failure in that small area can burn thru the deck after the gasket fails.

running the race gasket (.039) with iron heads. and it has taken prob 50 or 60 passes for these to fail. yes hopefully the block is not hurt. but we will check all that out.

Posted By: therocks

Re: cylinder pressure and gaskets/fasteners??? - 09/07/09 03:33 PM

I guess 550 isnt enough to worry about.But it runs and drives.Rocky