Difference between outboard & I/O prop?

[df909]

Hey Guys-

My neighbor just gave me a Quicksilver Trophy 22p 4-blade SS prop that he took off his BlackMax 150 outboard. It's in perfect condition without even a scratch and it was free.

I have a 2bl 4.3L Alpha 1 Gen II with a chewed up 3-blade 21p aluminum. I get about 4200-4300 max RPM at WOT & I should be getting 4400-4800 RPM. I was told that having a dinged prop with even a little bend to one blade will reduce the RPM's quite a bit.

My question: what's the difference between an outboard vs. I/O prop? The prop he gave me has holes the size of a nickel at the base of each blade. What're the holes for? Will having a slightly/moderately dinged prop reduce RPM's much? Last, how do you think mine might run with the 22p SS 4-blade?

Thanks very much.

 

[cribber]

Re: Difference between outboard & I/O prop?

The difference is not is a prop suitable for an I/O or outboard, it all depends on WOT RPM, HP, gearing, and weight to name just a few. Taking your 21" pitch 3 blade to a 4 blade SS 22" will likely cause you to lug the motor and drop your WOT RPM below recommended minimum. Give some more details as found here:

http://forums.iboats.com/showthread.php?t=287818

Then the experts can help you out with where you should be with your prop pitch. Good luck!!

 

[Bondo]

Re: Difference between outboard & I/O prop?

Ayuh,... The prop will bolt on,+ run, but as noted, it's the wrong way with the pitch...

 

[df909]

Re: Difference between outboard & I/O prop?

Thanks guys. I kinda figured you were going to say that. I was hopeful that I'd be able to use it since it was freeee.

 

[Fun Times]

Re: Difference between outboard & I/O prop?

Thanks guys. I kinda figured you were going to say that. I was hopeful that I'd be able to use it since it was freeee.

Well if you're in So. Cal and if your rpms are close to where you need them to be but need a little more out of it and you like the way the prop seems to work for how you want to be boating, Then you might be able to get the free prop reworked a little bit to get you're rpms back up by this guy. See this link. He will do a good job for you if needed.
http://www.hillpropellers.com/contact.html