Speed Question?
 

I have a friend that has a 21 foot Raven powerboat. I think that the V is between 21 - 24 degree. It has a brand new 350 roller motor (approx 325 hp.). Currently he is running a 3 blade 20 p mercury mirage on an Alpha drive at 4500 max rpm's . The manufactor of the motor said he should be running 5000 to 5250. Here's the problem, on a good day the boat might brake 53. Obviously, our first concern is getting the r's up to 5200. What prop should we try. I know we have to go down a bit on the pitch but 17 sounds a little small for the boat. Any recomendations would be great.

P.S. I already tried to get him to buy a Baja.....No dice.

With that kind of HP I would think he should be spinning that 20 much faster, might need to look somewhere else..My 0.2 cents

I'm questioning the claims of the engine builder. With 325hp and a 21' deep-vee boat, he should be hauling-ass and spinning that prop a lot faster. Something doesn't seem right. My first guess for a 21' boat with a fairly powerful small block(325hp), a 25P prop would be closer.

I agree Baja Daze. There is definatly somthing else going on. I think I would be questioning the builder. Need for Speed, has he ever had it on a dyno??? If not it might not be a bad idea.

That boat should run 70 with a 25 something is wrong with the picture

Whatever you come up with, I have a 19p Mirage Plus that I need to sell. Less than 10 hours, perfect condition. $275.00.

Let me know

[email protected]

If you have less power than the dyno guy is saying, you may need to try a 19p.

Good luck.

20 PITCH MIRAGE
 

ARE YOU SURE IT IS NOT A 21 PITCH MIRAGE AS THEY MERC does not build a 20 pitch Mirage prop, or has someone re worked the prop? also, if it is a stock 21 pitch buy allen 4's 19 mirage and have it labbed or repitch the prop you now have to a19 and lab it/my 2 cents/can't say on the motor/ but there are are alot of members that can guide you the right direction. good luck /let me know if we can help on the prop

.Darin