Prop question
 

I just put a brand new 454/330 in my 260 Stinger. It's a complete roller motor w/Holley 650, Stainless Marine 4" exhaust and a Bravo 1 outdrive. I understand the RPM range should be in the 4400-4600 range. I have three props 21, 23 & 25 pitch all three blade. What would be the proper prop to use. I think my 260 wieghs approx. 6000 lbs. The boat originally had twin SBC 350/260's in it and I converted it to a single BBC 454/330. Lost about 800 lbs in wieght and 260 Hp. Any help would be greatly appreciated, Thanks

The 3 props I have are: Laser II 48/25P, Laser II 48/21P and a Quicksilver Mirage 48/23P. I hope this helps you help me...

http://www.rbbi.com/folders/prop/propcalc.htm Click on the web site, it's a prop calculator. Hope this helps ya!

Not very good speeds out of the above formula. What can I do to at least get into the 50 mph range. Would it help to get a four blade prop or what. Any help is appreciated.

You will need the blade area of the Mirage propeller. Try that first. Get some base line info and we can offer test propellers determined off the info you supply.
Because this is a major adjustment to the boat, a beginning baseline is the first step. Everything else is speculation.

Let us know, this is a interesting project!

Brett

Brett, Thank you for your time & response. I will be putting SHOWTIME in the water this weekend. I'll put the 23P Mirage on before I head out to get the baseline stats and foward the results to you. Thanks for the advise on where to start. You're right this has been an interesting project to say the least. I ran a thread on my budget restoration project in the classic section, "Stinger 260 Facelift" check it out. Thanks again. Gator

Gator I agree about the blade surface of that Mirage 23P, but I'm thinking with a full roller motor, shouldn't you be more like 4600-4800 rpm range? Just curious. Hope the test goes well

Mac I would like to get those rpm's and may. But I only have about an hour on this motor and want to break it in. I definately don't want to build another engine unless I go bigger and all out. Which I may do over the winter...

Makes sense gator. Easy on the throttle :evilb: and you'll get those rpm's! I think that 23P is the right call.

Here she is running in the boat.

[YOUTUBE]http://www.youtube.com/watch?v=KkzpmKCssv0&feature=g-upl[/YOUTUBE]

Brett, I ran the 23P Mirage today, 42 mph (GPS) @ 4400 rpm's, full fuel (120 Gals.) and 4 adults. Boat ran awesome just has no speed. If I could get 50 mph and I would be happy...