Originally Posted by green lightning

....nobody told me my engine set-up looked like ****.

Originally Posted by articfriends

All depends on your HP goals. A M-3 gets "small" quick on a 572 if your trying to make real HP, if your talking low hp like 700,800, 900, it will be plenty fine. A 572 should make 700 on its own though. All this talk about intake runner "head CC's" between the 335s AFRs and 357s, keep in mind AFR uses the SAME EXHAUST PORT in the 315, 335 and 357. To best of my knowledge the 357 exhaust port will flow exactly same as the 335, ZERO exhaust flow advantage. As far as the Intake, you can force feed air thru a mediocre port and the 335 is far from mediocre. Im not ambitious enough to go look it up this morning but if you research the various AFR heads, you will see as they get bigger and bigger they actually flow LESS at the lifts most marine engines use so do your research there. Alot of boater guys forget the majority of boat engines DONT turn the rpms to come close to using alot of these "big" intakes, heads, huge cams etc.
As far as prochargers vs accel tq, vs boost, yeah sure, put one on something and pulley it to make 3 or 4 lbs of boost on top end, of course your not going to see a bunch of mid range gain. alot of guys whove never owned either a whipple or procharger ramble on about this debate. My M-3 was pulled up to make 12 lbs on my everyday tune, Id have to go back and look at my dyno sheets but I made over a 1000 ft lbs of peak tq and over 800 by 3000, enough to shear off billet vert shafts and props hafts jumping on plane. Smitty

Originally Posted by Roo1113

Oh its going in a smaller boat... its in a baja h2x.... I know over kill and some with think im dumb but it's what I want... its a fun smaller boat with my 509 and procharged set up... so be even more fun with the bigger stuff in it...

Originally Posted by articfriends

My M-3 was pulled up to make 12 lbs on my everyday tune, Id have to go back and look at my dyno sheets but I made over a 1000 ft lbs of peak tq and over 800 by 3000, enough to shear off billet vert shafts and props hafts jumping on plane. Smitty

Originally Posted by Tartilla

My Dad built a Glen-L Scamper boat...only 15' long. Put a wJ Jacuzzi jet into it in 1969. He had to wait a year to get it...they were on backorder. The Uniflite Vietnam patrol boats used the Jacuzzi.

He originally put a pinched out 283 engine into it. Then in 1975, got the BBC bug and put an LS5 that he warmed over with a Racer Brown Cam. Never went faster....but the upgrades he made were heavy. But he enjoyed it...

I think most folks have a genuine concern for safety...but if you're not in the driver's seat...it's hard to judge.

I tend to 'err on the more adventurous end of things, but I try to temper that with a healthy risk vs reward.

Originally Posted by KAAMA

And if I remember correctly, I think that was with a set of AFR 315cc Cnc ported heads on either your 509" or 540" engine---it was about 20 years ago so it's hard to remember all the details. Those little AFR 315cc heads made a total of 1115hp with your Pro Charger

Originally Posted by KAAMA

Well, they probably didn't want to hurt your feelings---(only kidding)...If you like it then that's all that matters. I believe every person is proud of his own stuff and I meant no offense, brother. Anyway, it sounds like a runner---glad you have enjoyed it all these years

Originally Posted by Roo1113

Oh its going in a smaller boat... its in a baja h2x.... I know over kill and some with think im dumb but it's what I want... its a fun smaller boat with my 509 and procharged set up... so be even more fun with the bigger stuff in it...

Originally Posted by GPM

I was just curious, I ran a M4 and M5 Procharged 598 in a 26 DCB, definitely need full hydraulic steering. I didn't have trouble pulling out with 1.35 gears and a 32 pitch prop. The 572 will make a major difference, build it with a 4.5 crank.