Cavitation plate height vs wot rpm

[reiddo1]

Re: Cavitation plate height vs wot rpm

A further update: Am now getting easily 5000 rpm with optimum trim at wot and 62 km per hour with my gps. If I trim out to the maximum the prop will ventilate, but at a trim level where I get max hull speed and max rpm, there are no operating issues at all unless I make a hard turn. I am satisfied with these results.

 

[bob johnson]

Re: Cavitation plate height vs wot rpm

A further update: Am now getting easily 5000 rpm with optimum trim at wot and 62 km per hour with my gps. If I trim out to the maximum the prop will ventilate, but at a trim level where I get max hull speed and max rpm, there are no operating issues at all unless I make a hard turn. I am satisfied with these results.

I d turn that motor at least another 500 rpm....that's 2" less pitch....... you probably wont lose that much speed ....maybe 3-4 mph........but your hole shot will be better and your motor wont carbon up as fast....just my opinion bob

 

[emdsapmgr]

Re: Cavitation plate height vs wot rpm

Agree with Bob. You'll be happier with a lower pitch that will get the engine closer to 5500. The engine will also be happier...

 

[reiddo1]

Re: Cavitation plate height vs wot rpm

I d turn that motor at least another 500 rpm....that's 2" less pitch....... you probably wont lose that much speed ....maybe 3-4 mph........but your hole shot will be better and your motor wont carbon up as fast....just my opinion bob

Thanks for your comment, but if I keep operating as is where my cruise is a say 4000 rpm, how will a prop with less pitch prevent a faster carbon build up? Seems to me I would be better off using Carbon Guard or Seafoam intermittently and running the current prop if indeed it gives greater speed than a lower pitch prop. If what I have just stated is true, my fuel consumption would be also lower with my current prop. What do you think?

 

[bob johnson]

Re: Cavitation plate height vs wot rpm

Thanks for your comment, but if I keep operating as is where my cruise is a say 4000 rpm, how will a prop with less pitch prevent a faster carbon build up? Seems to me I would be better off using Carbon Guard or Seafoam intermittently and running the current prop if indeed it gives greater speed than a lower pitch prop. If what I have just stated is true, my fuel consumption would be also lower with my current prop. What do you think?

what do I think?.....:joyous:I think you should turn it so WOT is 500 more rpms!! id use seafoam and carbon guard now and then ANYWAY.

 

[emdsapmgr]

Re: Cavitation plate height vs wot rpm

Running the engine with to high a pitch prop causes lugging (low top end rpm's.) Carbon buildup is aggravated by lugging the engine. Get the right pitch prop and you'll reduce the possiblity of carbon buildup around the ringsets and piston skirts. If you optimize your setup by getting a prop which will let the engine rev to the top of the "normal" rpm range, (5500) that's ideal. That prop will afford the best performance and the best fuel economy throughout the entire rpm range. If you cruise at 4000 rpm's that prop will get you better fuel economy and performance than the one you're running.