Re: lost comprsion on a cylinder or two any ideas 2000 454 mag
 

Did you use thread sealer on the head bolts?

Re: lost comprsion on a cylinder or two any ideas 2000 454 mag
 

no, I never heard of it

Re: lost comprsion on a cylinder or two any ideas 2000 454 mag
 

The head bolts thread right into the water jackets. Must use a thread sealer.

Re: lost comprsion on a cylinder or two any ideas 2000 454 mag
 

Ok thanks for the info, I also think a problem may have been trying to get out by the 4rth and could'nt find marine gasckets, and used auto gaskets, mabye they are a different thickness??

Re: lost comprsion on a cylinder or two any ideas 2000 454 mag
 

I've used automotive gaskets with no problems. You may want to presurize your coolant system to determine exactly where your problem may be. Could even be your intake gaskets. Go with the easy stuff 1st.

Re: lost comprsion on a cylinder or two any ideas 2000 454 mag
 

I assumed the intake, but I am gonna tear it back down and replace all gaskets with the mercruiser parts and use the thread sealer on the head bolts and go from there

Re: lost comprsion on a cylinder or two any ideas 2000 454 mag
 

Would'nt hurt to run a thread chaser thru the head bolt threads. If your head bolts have questionable threads, replace them. ARP makes an excellant thread sealer.
When you install your intake, get rid of the rubber valley gaskets! Place the maifold on the block to gauge the amount of silicon you'll need.
Check the mating surfaces on your inteake and heads on each of the four corners. May not hurt to dab a bit of aviation sealer on that as well.
GOOD LUCK>

Re: lost comprsion on a cylinder or two any ideas 2000 454 mag
 

Thanks, still waiting on gaskets