Prop Question

[skyguy59]

If I go from a 12&3/4" 21" pitch uncupped aluminum to a 13&1/4' 20" pitch single cupped stainless prop, what kind of RPM change can I expect? Will the cupped prop have a lower percent of slip than the uncupped prop? <br />TIA<br /><br />Russ In Texas

 

[Dhadley]

Re: Prop Question

Going from an uncupped aluminum to a cupped ss prop should produce a better bite. A cup should reduce slip. A ss prop should flex less. Without knowing the brands of each and what hull you have, its hard to say exactly what you will see.<br /><br />The big advantage of any ss prop over aluminum and cup vs non-cup is that you can run a higher X dimension. That means less drag and then the set up is more efficient.

 

[skyguy59]

Re: Prop Question

The aluminum is stock OMC, I'm not sure what the SS is. I think Rampage, does that sound right?. It would be run on a Glastron Carlson CV 16 with a 100 HP Johnson.<br /><br />Russ In Texas

 

[Dhadley]

Re: Prop Question

A CV 16? A very cool ride!! That boat responds well to set up changes. By all means try the Rampage. If it were mine I'd try a Raker or a Stiletto. With a jackplate I'd look for a Turbo.<br /><br />What year motor?

 

[skyguy59]

Re: Prop Question

Boat, motor and trailer are 1972 as delivered from the Glastron dealer. I'm the third owner. The original delivery order is still readable. The boat is really cherry and doesn't look as if it was ever used much. Everything is original and all of the emblems are present. Gelcoat buffed out and shines like new. It's been a cool project to restore. Now I have to work the last of the bugs out and do the setup thing. Initial test run was limited but I did get 45MPH (GPS) @ 5400 with quite a bit of throttle left. I'm guessing it will go 56 to 5800 at WOT with me solo. I need to run this prop abit more but I shorted a shift switch this afternoon and the ride got cut short.<br />I'm not thrilled about the electric shift but I want to keep it original. Any more suggestions would be most appreciated.<br />TIA<br />Russ In Texas

 

[Dhadley]

Re: Prop Question

Sounds like the set up is pretty good as is. Those old lower units werent the greatest at picking up water at high X dimensions. <br /><br />You'll have a ball with the boat. Humm.. pics would be nice..

 

[skyguy59]

Re: Prop Question

Thanks Dhadley. I have to figure out how to post pics on this forum then I'll get some up.<br /><br />Russ In Texas

 

[walleyehed]

Re: Prop Question

DH, would scoops work on this lower for him, and allow a slight bit more rise???

 

[Dhadley]

Re: Prop Question

It might if he went to a jackplate. The ones from E/J have been discontinued unfortunately. Without a jackplate I've run those same version motors all the way up on those boats with no problem. Even with the old props we had available then.

 

[skyguy59]

Re: Prop Question

Thanks for the input guys. For right now I'm going to stay with the stock setup and see what I can get it to do. My 46 Champ (airplane) is restored to all original because that is how it was delivered from the factory. I was lucky enough to get this rig also as delivered. It's already going to go faster than I want to go on a regular basis anyway. Kind of one of those " a CD player doesn't belong in a 55 Chevy" things.<br /><br />Russ In Texas