Rpm question

[water wiggle]

Okay here is the skinny 1988 Blue water 19' open bow 5.7 260hp alpha one. Specs for this motor are 4400-4800 wot. I just put a 19p aluminum 3 blade solas on and I am turning 4500 at 49.6 on the gps. Great hole shot and I am happy with the top end .Am I okay, or should I go down to a 17p to get the rpms closer to the top end of the range(4800) wot? Thanks

 

[steelespike]

Re: Rpm question

I'm sure no expert but it sure seems to me that a 260 in a 19ft would run something like a 23 pitch and 50+ mph.If the blue water is really heavy deep V maybe a little slow but I think the pitch would be in the 20S.You may want to check compression,tune up,good prop,clean bottom.
In my opinion the motor will be happier in the lower end of the rpm band.
However if you run heavy loads and have difficulty staying within rpm band you may want to drop to the 17.To me a rediculess number with that combination.

 

[water wiggle]

Re: Rpm question

I could be wrong on the hp rating but it is a 5.7 with a 4bbl carb. It is possable it is the 210hp The boat is a very deep v and heavy. I took a bad 17p off when I bought it and replaced it with a 19p. Like I said I am happy with the top end I was just curious if I would be better off runnig in the higher end of the rpm band. Prop is new, bottom is clean and motor runs fine. I do not carry alot of weight, 35 gallons of fuel and 2 people, Thanks

 

[steelespike]

Re: Rpm question

NADA says 230 hp 2350 lbs. I still think it would normally run a prop in the 20s.but if your happy with your setup and can run within rpm band your ok.
but I think you have some sort of problem.

 

[Scorpion 210 LTD]

Re: Rpm question

Okay here is the skinny 1988 Blue water 19' open bow 5.7 260hp alpha one. Specs for this motor are 4400-4800 wot. I just put a 19p aluminum 3 blade solas on and I am turning 4500 at 49.6 on the gps. Great hole shot and I am happy with the top end .Am I okay, or should I go down to a 17p to get the rpms closer to the top end of the range(4800) wot? Thanks

You are right in the RPM range and the 19P should give you a better holeshot for water sports. If you are looking for top end, you can go into the 20s otherwise enjoy your boating.

 

[a70eliminator]

Re: Rpm question

Just for comparison, I have a 20' open bow with a 5.8 similar in HP to yours and the boat also runs about 4400 RPM's at 49 MPH, I replaced the 3 blade aluminum 19 prop for and 18 pitch stainless just to keep the motor happy with boat fully loaded fuel people and gear and couldn't be happier, She jumps up on plane when fully loaded, but with just me I have to be carefull WOT will pass the redline but thats ok I don't have a problem with that, I don't think it's a bad thing. I would rather have more throttle control than just jam it foward and go.