Merc 2.5EE block vs FF top rpm

[coffeeguy]

Realistically how much HP and top end rpm(allowing for good pistons but not porting) is the EE giving up vs an FF block? I am aware of the exhaust chest differences. It would be on a fairly light boat. The EE has the 7 petal front ,abit of compression(under 145psi) and the efi is a brucatto to get around the rev limiter.

[Merc 2.5]

Kinda tuff question , as for max rpm, my guess is stock,merc set max rpm @wot round 5800 but I'd say both same, I dont know much bout ee block , maybe look up stock sleeve for ee motor and for ff motor and compare the #s?? I do know the ff sleeves is same part# for promax , so I'd be interested in knowing your findings unless sumone has experimented with this ?

[coffeeguy]

The difference in the sleeves(using a promax sleeve for comparison) appear to be the bleed off ports. Port shapes are the same,using plastersine . Port heights I have not measured yet.

[patchesII]

Big difference between these two blocks is the chest. For normal boaters I doubt you’d see much difference. When racing I doubt you’d get the EE over 8500. The FF can spin to near 10000

[coffeeguy]

I would like 7000-7500, wether that is possible with out chest work I do not know.
Our rules do not allow any block,piston or rod work so I have to work with unmodified parts.
With efi would I be better to stay with the 7 petal front or go with a 5 petal?
The EE did come with a 7 petalwhich I have

[Merc 2.5]

Anything over 7k for a long time is gonna put a beating on the stock side pinned pistons and plastic cage bearings

[coffeeguy]

I will be using metal caged bearing. Still deciding on a piston.

[mach351]

I spin my EE’s up to 7600.....at that point you can really feel them start to struggle.

[TEXAS20225]

i have two 200 blocks Mr Perry both setting untouched after return from machine shop, he put 6 new sleeves in each block ee and ff the top end on consumer style motors would be very close to each other however the ee blocks have shown me they are a lot more aggressive on hole shot on heavier bass boats ive built several of each one from him. when i got a guy with a champion or ranger or skeeter i would give him a ee block and efi , most of them loved the hole shot they were not up on the ff blocks chest difference not to much diff on porting

[friendbroker]

question on 225 promax I don't know if it's EE or FF I found either NN or ZZ on the block depends how you read it ? but it's not painted black I'm looking to overhaul the engine as preventetive maintenace many sites sell an overhaul kit pistons bearings gaskets etc approx 1200$ for the kit for a 2.5 Merc are the pistons form these kits a match for a promax block ?

[Merc 2.5]

PM block is nn, the machine shop guy will tell u what size or sizes u need , promarine or wsm best choices. Jay Smith can hook u up also

[coffeeguy]

I am in Canada. Its a whole different ball game.

[Varmint]

I am in Canada. Its a whole different ball game.

Call dave scott@ aim marine inc. Full merc dealer with a machine shop,,he uses wsm usually on my motors,613 831 1246, my last complete wsm kit with steel caged bearings,went into my 2003 200efi and came back at 140psi

[Varmint]

I am in Canada. Its a whole different ball game.

Call dave scott@ aim marine inc. Full merc dealer with a machine shop,,he uses wsm usually on my motors,613 831 1246, my last complete wsm kit with steel caged bearings,went into my 2003 200efi and came back at 140psi. I have a 99 FF sitting at his shop now needs a sleeve

[friendbroker]

[QUOTE=Varmint;3120195]Call dave scott@ aim marine inc. Full merc dealer with a machine shop,,he uses wsm usually on my motors,613 831 1246, my last complete wsm kit with steel caged bearings,went into my 2003 200efi and came back at 140psi. I have a 99 FF sitting at his shop now needs a sleeve[/QUOTE

I'll follow up after I take it appart it still pushes 140 to 145 all 6 holes so I expect things to be in good order inside just want fresh parts in it to make it last Thank you