3.0 head gasket choices

[tubenewb]

88 mercruiser, using the 88 head with a 75 block..both original GM gaskets when pulled apart or at least they have GM marked on them..
i believe the 75 had a steel shim style while the 88 had a composite with cylinder rings.

Now I thought I read there was a deck height difference in the years , maybe that would be the deciding factor..i know the pushrods were the same length..

Any reason I should use one over the other? I know this shim style from Sierra is like $20 and the comp syle is double or better..
so not sure if its adeck height thing, a gasket thing or a head thing..
Any help would be greatly appreciated.

 

[dubs283]

Re: 3.0 head gasket choices

well, i don't know for sure which gasket will perform better for you but i do know that the casting on the 1975 block is probably going to be better than the casting on the 1988 head

GM has used the same mold for those engines since the 60's and nowadays the castings are so bad that the timing spec is 2 degress ATDC due to head gaskets failing

if i were gonna try this i would use a head gasket that is designed more for the newer (1988) application than the older style

 

[tubenewb]

Re: 3.0 head gasket choices

That sounds like something to consider..I am looking into that and will double check with the machine shop to get his opinion.. I also stumbled onto the Fel-pro 17200 marine gasket..Comparable in price to the Sierra replacement composite.
Thanks for the info, I will keep researching on the gasket failure thing.

 

[tubenewb]

Re: 3.0 head gasket choices and Cam timing gear

Re: 3.0 head gasket choices and Cam timing gear

Finally got on the horn with the machine shop..He highly recomended the Felpro marine gasket wich I believe is the performance oriented perma-torque gasket in the auto world..So I will go with that..
While I was on the phoen I had asked about timing gears and that I had came across the choice of aluminum..
He recomended the aluminum over the fiber gear..He did state that it may be noiser but he felt it would be stonger or less likely to loose a tooth..
figured i'd share the opinion

 

[Fordiesel69]

Re: 3.0 head gasket choices and Cam timing gear

Re: 3.0 head gasket choices and Cam timing gear

May want to go with head studs to make certain HG failure does not occur again.

 

[alilley]

Re: 3.0 head gasket choices and Cam timing gear

Re: 3.0 head gasket choices and Cam timing gear

i just finished rebuilding a 3.0 and used that felpro gasket. got it fired up yesterday (no water time yet still tweaking it a little) and yet to have andy issues. no i have torn three 3.0/181/140 appart and all 3 of them had that thin metal shim style gasket and all three was burned across in between 2 and 3 and i recall readding at least 2 other post in here as well about the same issue with the shim style gasket.......im my book flrpro makes a really nice gasket and you went with the right one.....if it helps the felpro number for the rest of the gaskets will be 17100 that was for a 84 model year

 

[tschmidty]

Re: 3.0 head gasket choices and Cam timing gear

Re: 3.0 head gasket choices and Cam timing gear

I had the steel shim also burned across 2 and 3 (post with pics http://forums.iboats.com/showthread.php?t=449305).

My guess is that all of those steel ones are either older styles, or had been replaced with the wrong one. The Mercruiser manual specifically states 'DO NOT use steel automotive style head gaskets,' which seems pretty clear to me.

 

[tubenewb]

Re: 3.0 head gasket choices and Cam timing gear

Re: 3.0 head gasket choices and Cam timing gear

May want to go with head studs to make certain HG failure does not occur again.

I am hoping I will be OK with the standard bolts and the felpro marine gasket..I havnt experienced the failure myself .But the 75 shim gasket had the break between 2 and 3..all fresh machine work and that gasket should be all good I hope

i just finished rebuilding a 3.0 and used that felpro gasket. got it fired up yesterday (no water time yet still tweaking it a little) and yet to have andy issues. no i have torn three 3.0/181/140 appart and all 3 of them had that thin metal shim style gasket and all three was burned across in between 2 and 3 and i recall readding at least 2 other post in here as well about the same issue with the shim style gasket.......im my book flrpro makes a really nice gasket and you went with the right one.....if it helps the felpro number for the rest of the gaskets will be 17100 that was for a 84 model year

Thanks , good to hear its running well so far..I hope the worst of my problems is tuning a carb and setting the timinmg lol

I had the steel shim also burned across 2 and 3 (post with pics http://forums.iboats.com/showthread.php?t=449305).

My guess is that all of those steel ones are either older styles, or had been replaced with the wrong one. The Mercruiser manual specifically states 'DO NOT use steel automotive style head gaskets,' which seems pretty clear to me.

Ya the one i pulled from the 75 had the same break, seems like enough reason alone to stay away..
Thanks for the input gang