More RPM vs. 4 Blade Prop

[mtnlkstriton]

I have a 225 Optimax Pro XS on a Triton 19 X2. The optimal RPM range is 5500 to 6000. The best I've been able to get under the right conditions is 5600. I was thinking about trying a 4 blade Trophy Plus Prop with a 21" pitch. I am currently running a 23" Tempest Plus. Would trying the 21" 4 blade do some good, or would I be wasting my time (and money)? Also, the elevation of my home lake is 6200' (loss of HP for high elevation, I know).

thnx

 

[Philster]

Re: More RPM vs. 4 Blade Prop

Did you mention how many blades your current prop is?

Without that info, no one can make a suggestion.

 

[180shabah]

Re: More RPM vs. 4 Blade Prop

If you are currently running a 4 blade, then the 21" should get you just about where you want to be. If your current prop is a three blade, thenthe new prop, will probably put you in the 57-5800 range.

Of course this is all just speculation - we need to know exactly what prop you have now.

 

[mtnlkstriton]

Re: More RPM vs. 4 Blade Prop

Sorry, the Mercury Tempest Plus is a 3 blade prop. The prop is ported with the removable plugs and am currently running it with one port open. Two open, it is more difficult to get on plane with passengers and with all ports open, getting on plane is near impossible. My thought on the 21" 4 blade was to have the extra blade in the water to keep the rpm's from getting too high, tight turns, rough water, and running a 4 blade with the same pitch would reduce overall rpm from what I'm getting now with the 23" 3 blade.

thanks in advance for your input...

 

[Dhadley]

Re: More RPM vs. 4 Blade Prop

OK, the Tempest and Trophy have different traits. The Tempest is more of a bow lifter and the Trophy is more of a stern lifter. Most Tritons that we've been involved with benifit more from props with bow lift.

That being said, there are 4 blade props with bow lift. Is that what you're looking for?

 

[mtnlkstriton]

Re: More RPM vs. 4 Blade Prop

My boat has plenty of bow lift. How much stern lift are we talking about? 1 or 2 inches? This would could cause more of the running surface to be in contact with the water creating more drag and less top end speed, correct?

I was looking for a way to increase engine RPM by downsizing the pitch, but not too much which is why I was wanting to try the 4 blade (extra blade to create a little more drag or resistance so not to increase too much rpm). How will this affect overall thrust of the prop?

I do know that similar engines in my area have 4 blade props, but none of them are Triton from what I've seen.