OMC gaskets?

[Cut n' Jump]

I just tore down a '89 model 350 Chevrolet..er omc in need of a valve job. Will standard fel-pro gaskets be fine? Reason is the gaskets on there are very strange looking to this auto mechanic. I am afraid of long term corrosion affecting the fel-pros. Also the leaky intake valves on 5 and 8 cyls. seems odd. Any ideas on the reason for intake valves leaking? I'm sure it isn't carbon. I haven't removed the heads yet since I ran out of time today- so I don't know if they are bent burned or whatever.

 

[Boomyal]

Re: OMC gaskets?

Marine head gaskets have a stainless sealing rings to resist corrosion. Unless you are running a closed cooling system, with ethyene glycol, I'd run what ya brung. Another issue may be the thickness of the gaskets. Marine gaskets (may) be thicker. That would affect compression ratio.<br /><br />As to your leaking intake valves ????? bent or carbon would be the only thing I can think of. Er, a, wait. Could be erosion. If you had a leaking head gasket, the valve seats could have become eroded.

 

[Boatist]

Re: OMC gaskets?

Valve at the back of the engine are the first to go when have a leaky exhaust manifold because thay are the lowest. usually exhaust 7 and 8 valves.

 

[Bondo]

Re: OMC gaskets?

I am afraid of long term corrosion affecting the fel-pros.

Fel-Pro makes some of the Best Gaskets.......<br />Just ask your Parts Guy to look up Marine #s.....<br />

Any ideas on the reason for intake valves leaking?

Rust..........................

 

[Cut n' Jump]

Re: OMC gaskets?

Yeah, I got marine felpros at double what automotive ones cost. 5 intake valves bent badly enough to not be grindable. One was actually 'tuliped' and tried to pull through the seat. I couldn't get any stainless valves till wednesday so 8 regular sealed power valves went in. I'm wondering if the stellite exhaust seats were factory equipment on this engine???? Impressive sodium filled 3/8 stem exhaust valves were very grindable This engine is like brand new and it beats me how the intake valves all got bent. The power steering cooler was leaking water pretty bad so maybe it overheated, although the valve seals were still soft.

 

[vinney]

Re: OMC gaskets?

Seen that many times on OMC cobra's sometimes 350 Mag. engine. If the timing is up 10 to 12 degree's it will tulip the valves. Heat and a little extra timing will definitely tulip valves. Check base timing and the check total timing at 3000 RPM's.

 

[Cut n' Jump]

Re: OMC gaskets?

Turns out the timing was set 'by ear'. Book says 3* but initial was 24* ! It revved out of the water much better way advanced. I marked the distributer and put it back in the exact spot. The total timing at 3k rpm is 24* with the 3* initial. I'm thinking it should be bumped to 28* total, but won't do it unless someone says it's ok.

 

[Fishermark]

Re: OMC gaskets?

It's probably too late if you have already ordered a complete FelPro marine gasket set. All you really need are the marine head gastets and brass freeze plugs. You can buy a cheaper automotive gasket set and simply buy the individual marine items mentioned above for usually cheaper than buying the "Marine" set. Found that out the hard way myself!