kwb

I'm in the process of doing a valve job on my Merc 900sc's and was thinking of porting and polishing the heads while it's apart.

Would I gain more HP by puting on a set of Big Chief heads rather than porting mine? I realize I'd have to also replace my intake manifold.

What are the cost of the Big Chief heads and the Intake (Indy?)?

Thanks!

JimV

iTrader: (1)

You will have a butt load of money changing to the big chief heads. You will have to change you pistons. The big Chief's require shaft mount rockers. You will also need to change the valve covers. Your heads ported should flow close to the big chief's up to .650 lift. Good luck PS I know a guy that can port your heads.

kwb

Thanks Jim - that makes the decision easier.....

I'll probably just port what I have and save the $$ for next season when I may do a re-build.

What about the cam in the 900sc, should i keep the stock cam?

I am replacing all of the valves plus valve job etc....

Thanks

Ken

rpm

Port the heads, go to a hyd. roller cam and can you say 950+ legit HP instead of 850. You need to match the cam to the heads though.

Rod

kwb

I am running nearly 10lbs of boost now at wot.

I would like to keep the solid lifters even though they require more maintenance. I can turn higher rpm and don't have to worry about floating valves?

rpm

The cam is a custom grind. Std 900SC shortblock is 8.0:1 we went to 8.2:1 CR and ended up at 8 psi. Lift was in the .610 range and if I remember correctly duration in the 236/242 range on 114 centerline.

Rod

Back4More

Rod...Is that 935lbs of TQ i see there!?!?!

Audiofn

Kenny what about Extruded Hone? Has anyone tried this on a boat? I know people that have had it done on cars and it was a HUGE increas. MUCH better then the old style honing. They can get were the normal grinder can not. They also put the intake and heads on there and get on all the insides of your intake runners

Jon

rpm

Marc, 956@ 4400.

Rod

rpm

You can reach me at 920-236-4220.

Rod