I am also worried about the exhaust system. It could be reverting a small amount. The clean pistons and chambers are a clue as is the valve seat dropping and valves tuliping. Those engines really need longer risers on the exhaust.

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I used to have GIL exhaust but the risers cracked and I was gettin g water in the cylinders. When I buiotnthe engines I figured I should use a new exhaust to avoid reversion but didn't want to spend a fortune. I'm going to check the manifolds out and maybe invest in new risers.

For 598 Ci engines, u should get some stainless marine high tourge III nothing small will actually really be ok for high CI engines !!!!!:party-smiley-004:

598??? Woww I read in a rebuild spec sheet based on the bore and stroke I should be around 515ci (4.530 bore 4.00 stroke)

Am I missing a factor here?

Can I get away with the gill manifolds and these? http://www.cpperformance.com/p-13413...imensions.aspx

[QUOTE=CafeRacerPTY;3292023]598??? Woww I read in a rebuild spec sheet based on the bore and stroke I should be around 515ci (4.530 bore 4.00 stroke)

Am I missing a factor here?


Sorry, i was reading an other members post that had 598's and mixed it all up.lol

Gil are just outdated IMO and actually not to god. Its a small upgrade from stock.

I would not use those, they are also the short ones ( hight wise ) if anything u need the higher ones.

But that being said u can find good deals in the classifieds on used SM manifolds .


http://www.offshoreonly.com/classifi...o26868-en.html

PatriYacht,

"-6 size hoses should be added to the intakes to connect the rear water ports to the front water crossover. This helps prevent steam pockets from forming at the back of the cylinder heads and creating hot spots."

CAN you please elaborate on this and show some pics?

Thanks,
Cliff

What he means is run a hose form the rear water jacket of your heads to the front to make sure the water can circulate and not just stop back in the head.

u can see it on this engine ...

http://www.offshoreonly.com/classifi...o28545-en.html

Thanks for the pictures. I didn't have any handy. You don't have to use braided hose, it's low pressure water there. I just used brass push on fittings and rubber hose.