Offshoreonly.com

Offshoreonly.com (https://www.offshoreonly.com/forums/)
-   General Q & A (https://www.offshoreonly.com/forums/general-q-20/)
-   -   Building a 572 with m3 procharger (https://www.offshoreonly.com/forums/general-q/380172-building-572-m3-procharger.html)

KAAMA 08-09-2023 08:05 PM


Originally Posted by green lightning (Post 4876098)
....nobody told me my engine set-up looked like ****.

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

Roo1113 08-09-2023 08:05 PM


Originally Posted by articfriends (Post 4876058)
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


To be honest and I don't even know if it's possible but been told if I do it right should be around 1000 hp... and yes I agree if it's not there I aint gonna a be mad or upset or any of that... want good reliable power and torque . Which I get you have to be careful or you'll blow drives and all that... but im after making good all around hp and torque is where im trying to focus on... and yeah I was trying to keep it to where I would spin 5500 or maybe 6000 but don't want it to have to live there... honestly trying to set it up so my midrange around the 3000 mark i can cruise with ease not turning alot of rpm but can also get out of the hole... now I'm not saying I wanna punch it out of the hole but if I'm loaded with adults I want it to have enough s*** to pull it self and to be happy

Twin O/B Sonic 08-09-2023 08:13 PM

Great thread, great reading!

Tartilla 08-09-2023 08:35 PM


Originally Posted by Roo1113 (Post 4876160)
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...

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.

KAAMA 08-09-2023 08:37 PM


Originally Posted by articfriends (Post 4876058)
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

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

Roo1113 08-09-2023 08:40 PM


Originally Posted by Tartilla (Post 4876168)
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.

Yeah I over build things for sure... never gonna be trying to do 100 in the boat or anything but like to know its all there if you wanted it...

articfriends 08-10-2023 05:41 AM


Originally Posted by KAAMA (Post 4876169)
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

Yes, I made 1115 on kill with my afr 315s on a 540. They were modded however professionally focusing on exhaust flow by Rick Lapouttre a local expert head porter.

green lightning 08-10-2023 07:50 AM


Originally Posted by KAAMA (Post 4876162)
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

Nice, With all the comments you are making and the critiquing you are doing you must have some serious engines yourself

GPM 08-10-2023 02:19 PM


Originally Posted by Roo1113 (Post 4876160)
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...

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.

Roo1113 08-10-2023 04:49 PM


Originally Posted by GPM (Post 4876228)
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.

yeah I have full hydraulic steering but am running the 1.50 gear in drive...
and how come you say to build with the 4.5 crank and not the 4.250.. I was gonna use the standard deck height block and not tall deck... was trying to stay away from buying new exhaust as exhaust isn't but a couple years old


All times are GMT -5. The time now is 07:50 AM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.