best prop for i/o

I am looking for the best prop i can get for my i/o, not just for wakeboarding but for everything.

I have a 20 ft crownline with a 5.0L 220 V8
I don't have weight now but i may add some later

anybody

What outdrive do you have? If you have a Volvo, then the Volvo Viper (I think that is the name) is a good prop. Otherwise, I would look at a Mercury High 5 as the best wakeboarding prop. I used to have a 202BR and the owners forum on Crownline.com is very active and helpful. You may want to try there for advice too.

There's a lot more to it than that Erling.

What are you running now?

How is the hole shot?

SS will out perform Aluminum any day.

Again, outdrive? Duoprop or single?

What are your max rpms and how close are you now?

Progressive pitch or regular cupping? Which do you want?

Other factors: Adding weight? drop the pitch again.

Now, that said, with a small V8 and a 20' CL, I'd run around a 19" or so at a mile high. That would probably equate to a 21" at sea level.

With weight, go with a 19"

You'll have to test a few props. Period. Get with a good prop dealer adn they'll let you demo props until you find the right one. You demo deposit should go to a prop purchase. Figure on a couple hundred for a good prop.

SS beats Aluminum any day? Ever tired to prove that one?

I test the same prop back-to-back in SST and Al, no difference.

Having said that I think SST is better IF and ONLY IF the prop manufacture takes advantage of the material and thins out the blades etc.


Matt, I think your question five is the critical one to start with; what is the current WOT rpm and how close is it the rated WOT rpm.

cheers,

yes, After 6 boats and many props. Definite improvement.

I agree with the statement about thinnnig, but to me, that's a no brainer. An SS prop SHOULD automatically be thinner than Alum. Do you know of any SS manufacturers that don't? I'm not flaming, but I want to stay away from them if I need a new prop.

My buddy bought a boat with a volvo penta SX 190 hp(really OMC Cobra). I ended up buy the same boat. When he killed his prop, his marina sold him a SST replacement.

He brought the SST prop to my cottage and we tried it out on my boat. The props were identical... the only way you could tell them apart was the weight.

We ran a couple of tests; time to 20 mph and top speed. There was no difference! I felt bad for my buddy… but there was no difference at all.. maybe Al was a tenth faster hard to say!

After that I decided that unless the prop shape took advantage of the material there was no point. Any argument about being stiffer just doesn't wash with me.

Anyway... your last point was right on... "try a couple of props" Some of my friends race hydroplanes (very seriously) and there is a bit of a black art to props.

Oh and my final comment... most salesmen don't no jack about props....

So and I quote "You'll have to test a few props. Period. Get with a good prop dealer and they'll let you demo props until you find the right one. You demo deposit should go to a prop purchase. Figure on a couple hundred for a good prop."

OK, thanks. I was just wondering if there were some manufacturers using the same die/process to make the steel/aluminum props. I agree, SS should be significantly thinner than Aluminum.

Have fun, foiling and boarding for me tomorrow!

I'll probably get flamed for this but I run a Quicksilver pitch switching prop on my I/O. It's like the equivilent of a 15 pitch to start, and then switchs to a 21 pitch. While I'm boarding, it usually stays at the lower pitch which is nice because the boat is easier to control speed wise there. But when we're just cruising, it switches to the 21, and then we can get a good cruise speed out of it too. Best of both worlds for "my" boat, but you'd have to try it on yours.

Good luck!
Mike

Mike,

What's the cam wear like?

James,

Can you clarify your question? ("What's the cam wear like? ") I'm not sure what you're asking?

Thanks,
Mike

(Message edited by MNWake on August 08, 2003)

i thought aluminum props had to be reshaped after a year or so because they tend to loose their cup where ss wont
erling, what the others said, what outdrive is on it? I dont realy care what the rpms are like at full throttle, for wakeboarding your concerned with time to plane and holding speed. Ive got a 3400 lb 20'monterey with a merc 240 and a 19" highfive. Works great for me, maybe if i added alot more weight all the time id go for a lower pitch but???

thanks for all the advice