At what compression ratio do you guys start to consider it a 'must' to o-ring the block. Or is it more of a certain power level. Just wondering. Thanks, Scott
I think it depends on how comfortable you are with the compression ratio and rpm that you are turning. One of the Buick weaknesses is the fact that it is a 10 bolt head. This makes for low clamping pressure. That's why the TA stg2 heads add 4 more bolt holes to reduce head gasket leaks. I personally think 11.5:1 and under is ok without o-rings. I could be wrong but I've never seen one fail. Olds engines have that similar problem. I have a friend that has been street running a BB Olds with 12.5:1 for 5yrs without a problem. I went through 2 sets of head gaskets until a friend at an Olds dealer told me to try 350 Olds diesel gaskets. I installed the pair then retorqued while hot and got another 1/2 turn out of the bolts. Never had a problem after that. With the Buick that I'm trying to build now, it will get o-rings. I helped a friend pull an engine down after a blown head gasket had already been replaced and you should have seen the crap in the rings!!!:shock: It made me realize, "do what ya gotta do to keep this from happening to you!"
ratio Scott Been personally racing Buicks for over 30 years and have never O ringed a block,I've always run reasonable compression ratios though,.like 12 to 1 or less.However ,my current combo in great scat is a true 12.2 to 1 w/ stage 2 heads and still no problem without o-rings and over 350 passes and no tear down yet except to check bearings.Just make sure you retorque a couple times after initial fire up and cool down cycles.If your going over 12.5 or using happy juice definately o-ring,I think I'm probably pushing the envelope here a little but you never know untill you try.I did the same thing when using a girdle,untill I reached 600 HP there was no problem /with good assembly of course,then I started experiencing funky main bearing wear on #2and #4 due to block flex,never scattered a motor but had to replace the bearings every 100 runs,went with the girdle and problem solved.Have about 675 HP now and using same bearings as initially installed.Some guys are having real good luck w/o a girdle but pinning the main caps,also,the Poston pan girdle has been used successfully by many guys with over 600 HP.sorry for the rambling I'm off the topic. Hope my 2 cents worth help. gary
Hi Guys, Scott........I'm not saying that it's always needed but I ALWAYS O-ring just for the peace-of-mind it gives. Just as Gary said, re-torque is of the utmost importance! DO NOT for even a minute believe the claim that the Fel-Pro's are a true No Re-torque gasket. Myself, I re-torque three times on the stand then three more (or more) times after the engine has expierenced heat-and-cooling cycles. On the standard/Stage1 engines this is MUCH simpler than the Stage3/4's are because you do not have to remove the headers. The 3/4's are a pain in the butt in that sence BUT ARE WELL WORTH IT IN THE LONG RUN!!! As a side note.....I have used the Fel-Pro's on a Stage3 464ci with 15.47 to 1 comp. ratio with complete success following the proceedure I used above. I have heard claims been made in the past that they SHOULD NOT live with that kind of comp. ratio! My 464ci just didn't know that I guess!!:TU: Hope this helps.........
