Any prop suggestions

[FlyinZX14]

My boat is an 88 IMP Eleganza. They say it weighs 5600 dry so Im figureing Ill call it an average of ~6500. I built a 454, .030 over. It has a good set of iron heads with large stainless valves and bowl, pocket ported. It has a marine roller cam from comp cams. I estimate the engine should make around 450 - 475 hp. It has a bravo 1 drive...It has a 22 on it now and at 5000 rpm it will run about 58 ~ mph. I am in the process of putting a 177 blower on it. ..

With all that rambling above, can someone make an educated guess of what a good prop would be?

Would a 25 4 blade be out of the question?

Top end would be great but I would love to be able to cruise 50 mph without feeling like Im running it hard. If it would run near 70 top end I would be tickled pink, but with a boat thats near 7000 lbs, Im not sure it'll do it.


Thanks for listening, I appreciate any suggestions, and if anyone has anything I could try, that would be fantastic!

[Griff]

You should gain about 80-100 hp with the blower addition. That will probably put you around 63-65mph. I would plan on moving up 2" in pitch with the same model of prop. If you change to a different model prop, this could change. All props of the same pitch don't spin the same rpm.

[Soul Asset]

I can lend you what I've learned so far with prop selections from trial and error. I have a 454 w/ProCharger that I'm estimating to put out ~425 if all the literature and claims are correct. I have not dyno'd it, but it would be interesting. My boat weighs pretty close to what you listed, too. I had a Bravo 26p 4 blade that worked OK, but it lugged out of the hole and WOT was 4200 at around 58mph. Dropped to 21p Rev 4 4blade, the hole shot was phenomenal, but bounced the rev limiter at 3/4 throttle & 48mph. Tried a Mirage 25p three blade and it spun up like there was nothing there. I actually thought I spun the blade off on the first real stab of the throttle. I even heard the charger's pop-off during the spin-down. Was surprised to still see it attached to the shaft!

I don't think the three blades with that high of a pitch can handle the torque and power your motor will be producing. I'm sticking with the 4 blade, hopefully, I'll get to try a 23 soon. the Rev 4 has ventilation holes that I'm wondering if they were on my original prop, would give me enough slip to get out of the hole better and possilbly bring my WOT numbers to what they are supposed to be.

[FlyinZX14]

Some good info there! Thanks for the input!

[bbladesprops]

I think you will like the Revolution 4 as well.

Just a reminder, we have the complete line of Mercury propellers for testing. We also carry some Yurbos and Hydromotives for tsting.

Brett