Prop Choice

Turd Ferguson · #1 05-27-2008, 08:20 PM

Hey guys..I'm trying to pick out a prop

Here's what I got:

Of course a V
And for now I'm running an old Erude 85 (under powered I know); until I come across some money it'll have to stay.

I put a 17 on there and It's gotta enough torque to jump up
on plane instantly, The top speed however is low. Do you
think it could handle a 19 or more?

THEFERMANATOR · #2 05-27-2008, 08:43 PM

NO, I had a 115HP on my V-20 and was running a 15 stainless. You may actually be bogging it down to much, what are your WOT RPM's? Try finding a set of 140 carbs and a bubble back exhaust, or even better a blown 135 or 140 and swap the parts over to up your HP a bit to compensate some.

spareparts · #3 05-28-2008, 06:52 AM

get an accurate tach, in dash tachs are notorious for being inaccurate, borrow or buy a shop tach, check the max rpms at WOT, then go from there. That motor should be turning around 5500(right, Ferm?)

THEFERMANATOR · #4 05-28-2008, 10:09 AM

4500-5500 is the WOT RPM range, but beings you are underpowered I would prop it to hit the top end with just you in it. MAybe even hit 5600 with just you in it. Whatever you do though, DON'T HOLD IT AT 5750 RPM'S! This can result in an exploding flywheel

. OMC had an issue with the balance in the cross-flow engines, this is why 5500 was the max rated RPM for any of them. The pistons were so heavy that at 5750 they create a whipping motion and could tear the flywheels hub out. Quite a few cross-flow guy's on there bass boats have turned there flywheel's into frisbees trying to twist them up. It won't happen instantly, but it is a possibilty. So why take a chance.

Turd Ferguson · #5 05-28-2008, 03:18 PM

Thanks guys...Right now I'm still putting this thing together so I don't have a tach hooked up, I'll let you know as soon as I do, I can just say that It sound like it was spooled up pretty good