wiskebound
Cadet
- Joined
- Jul 14, 2010
- Messages
- 9
question on size, pitch and blades...
I have a 1996 caravelle interceptor, 23' with a 5.7 merc and an alphaone outdrive. I assume its about 220 hp and I just insitalled a 4 BBL intake and a 600 cfm 4 BBL carb so it may be a little more. Currently running a 14.5 X 19P aluminum prop. Everything is good so far. i am wanting to purchase a spare prop and im looking for some info to see if i should or could purchase a different size prop, so my questions are:
1)RPM's: At WOT it runs about 4800 to 5000 rpms, around 45 mph depending on trim. im being told that i should keep the rpm's around 4200 to 4500? what is best rpm range i should be in?
2)Pitch: With my hole shot being great now with the new carb(even with a tube), can i go up in pitch for a little better top end? maybe a 20 or 21 pitch?
Right now i can cruise at about 20 mph with out comming off plane, will a change in pitch change this?
3)Diameter: How much effects does the diameter have. I have about 3/4" clearance, would going to a 15" diameter make any changes? what changes might be see with a larger diameter?
4)Blades: 3 or 4 blade? Reading the info on the site, it says to decrease pitch around 2 inches when you go from a 3 to 4 blade prop and that the top speed will also decrease? Is this because you need the decreased pitch to turm the prop with the extra blade in-turn decreasing top end? (more drag requiring less pitch to turn in the water with the same amount of hp?)
Im thinking in the direction of a 4 blade but i really think i need some opinions from people that have ran both...
As usual, im wanting the best of all worlds!! I should realize by now that its imposible.
Thanks for any and all input!!!!!!
I have a 1996 caravelle interceptor, 23' with a 5.7 merc and an alphaone outdrive. I assume its about 220 hp and I just insitalled a 4 BBL intake and a 600 cfm 4 BBL carb so it may be a little more. Currently running a 14.5 X 19P aluminum prop. Everything is good so far. i am wanting to purchase a spare prop and im looking for some info to see if i should or could purchase a different size prop, so my questions are:
1)RPM's: At WOT it runs about 4800 to 5000 rpms, around 45 mph depending on trim. im being told that i should keep the rpm's around 4200 to 4500? what is best rpm range i should be in?
2)Pitch: With my hole shot being great now with the new carb(even with a tube), can i go up in pitch for a little better top end? maybe a 20 or 21 pitch?
Right now i can cruise at about 20 mph with out comming off plane, will a change in pitch change this?
3)Diameter: How much effects does the diameter have. I have about 3/4" clearance, would going to a 15" diameter make any changes? what changes might be see with a larger diameter?
4)Blades: 3 or 4 blade? Reading the info on the site, it says to decrease pitch around 2 inches when you go from a 3 to 4 blade prop and that the top speed will also decrease? Is this because you need the decreased pitch to turm the prop with the extra blade in-turn decreasing top end? (more drag requiring less pitch to turn in the water with the same amount of hp?)
Im thinking in the direction of a 4 blade but i really think i need some opinions from people that have ran both...
As usual, im wanting the best of all worlds!! I should realize by now that its imposible.
Thanks for any and all input!!!!!!