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- - BBC 0.700" wheel, hyd roller lobes. (https://www.offshoreonly.com/forums/general-q/381199-bbc-0-700-wheel-hyd-roller-lobes.html)

Quote:

Originally Posted by getrdunn (Post 4886568)

The smaller runner and 2.3 int valve will create better velocity and air speed. Engine will be happy with right combo. Your CI warrants either single plane or dual but I’d lean towards SP for port consistency etc.

What kind of boat?

Old 26ft cc stinger. Intake manifold is a big question for me right now? I have ms2 efi collecting dust at ny carag, that i could use. Option 1=ms2 efi with single plane intake. Option 2= ms2 efi with modified 502 mpi intake. Option 3= edelbrock rpm dp 7164 with 850cfm rochester q-jet.

https://cimg3.ibsrv.net/gimg/www.off...74ed54f16f.jpg

Quote:

Originally Posted by JaniH (Post 4886550)

4" taller vs stock and dry to transom riser.
https://cimg3.ibsrv.net/gimg/www.off...69fa965f45.jpg
https://cimg4.ibsrv.net/gimg/www.off...c71c357fc1.jpg

Okay, so how do you know it needs less duration split ?

Quote:

Originally Posted by SB (Post 4886586)

Okay, so how do you know it needs less duration split ?

Actually i dont, thats just what i have read from several topics. Have been thinking how the current cam would do, i quess the better heads could shift the peak hp/tq upper in the rpm range by severeal hunred rpms, dont know.

Quote:

Originally Posted by JaniH (Post 4886588)

That’s my point.
So why seek one out ?

Wait.
2.3” intake on 4.25” or 4.310” bore. That gonna work okay ?

Quote:

Originally Posted by SB (Post 4886591)

Wait.
2.3” intake on 4.25” or 4.310” bore. That gonna work okay ?

030 over 502= 4.5" bore, bores are already notched.

Quote:

Originally Posted by JaniH (Post 4886592)

030 over 502= 4.5" bore, bores are already notched.

oh, few. For a hot minute thought you had a 496. (Stroked 454)

Quote:

Originally Posted by JaniH (Post 4886592)

030 over 502= 4.5" bore, bores are already notched.

No not drunk just can’t sleep! Your rod length one more time???

Im kinda surprised your current cam with said duration is peaking 5300/5400. With that said and you plan to stay around the same I’m not so sure I’d change your cam. Heads will be a big improvement… they’ll make your power.

(Comparison) The 236/244 dur cam in 509 was pretty much done at 5500. I definitely would be careful with to much duration on single engine heavy V bottom. (Looks nice btw)

In regards to the split I’d (think) 4 to 6 deg would be about right with those heads. GM heads with chitty exh ports maybe 12 - Just sayin! My worked over promaxx’s like 4 deg split. The ratio btwn int and exh is pretty efficient.

Quote:

Originally Posted by getrdunn (Post 4886620)

Rods are 6.385". The peanut head was the bottle neck in the old combo, 220cc ported/ 2.35sq" intake csa, I/E ratio around 72%. Flotek I/E ratio is atlest 80%, and intake csa is 2.95sq". Anyhow the samll ovals made suprisingly good power, flowing only 280cfm at peak lift, low lift flow was good. Floteks outflows the current heads starting from 0.500" lift.

Suddenly this popped out at facebook marketplace, i had to buy it with gaterman gp1002 roller lifters. comp cams custom marine grind. Have to get the floteks flow tested after seat/valve job and see wich cam suits the best. The new comp has less lift, but with 1.7 crane golds it is right at 0.600".

https://cimg4.ibsrv.net/gimg/www.off...4b5841a044.jpg