rjewell1988

Hey guys just finishing up a 540 build for my Powerquest 270 Laser, originally a 502 boat. Motor should be making about 675 hp with a 741 cam which says its good up to 6000 rpm so shooting for 5800ish. It orignally had a Quicksilver 21p 3 blade. What would be a good start prop wise to move up to. I know im going to have to try a few to get it dialed in just right. Thanks

Rookie

iTrader: (4)

A 21 3 blade...
You need to spin more RPM's and with more RPM's comes speed.

rjewell1988

But wouldn't I be over powered and just soon the prop out being almost double the horsepower then the stock 502?

dereknkathy

you might not be at the hp figure you are hoping-expecting. always start with the paid-for prop. get several different speeds at rpm's. see how easily it goes up to your target WOT rpm. what rpm did the 502 turn that prop to? if it wants to keep revving, don't let it. you haven't spent enough on your valve train to do 7000.

Mr Maine

A 741 cam in a 540 may only make power to 5k, whats heads are on it? Did you dyno it?

edit: I was thinking of the 731 cam which is smaller.

bbladesprops

Start with a prop you or someone else has in the 21-25 pitch range keeping R's where you want them (if it over revs). This info will point you in the right direction.
We have a test program at BBLADES if you wish to try some props.

BBlades Propellers | BBLADES Propeller Test Program

Brett

rjewell1988

I have canfield 315 heads. I was hoping to get to 5800 rpm or so cam says its good for 6000...... but in reality who knows. Its hitting the dyno tomorrow to get true numbers and a tune then in the boat it goes. And ill look into the prop program thanks