high five prop on 3.0l

[micsol]

I have a 97 175 with the 3.0l and alpha 1 gen 2 outdrive 2.0ratio. the boat came with a 17p prop (Im not sure of the diameter). right now the boat does really well pulling a tube or wakeboarder. but the top end sucks. My question is what kind of compromise can I get going to something like a highfive prop with something in the neighborhood of a 19 pitch. or is this not worth the cost.

 

[eavega]

Re: high five prop on 3.0l

First question is, what is your WOT RPM with a normal load? If the motor is running well within your recommended RPM, then switching to a higher pitched prop is not going to do you any good and may cause you to lug the engine. If, however, you have speed to spare, then a higher pitch will get you that top end you are looking for.



Rgds

 

[steelespike]

Re: high five prop on 3.0l

I think he may have meant" rpm to spare".What is the present rpm at wot all trimmed up?

 

[micsol]

Re: high five prop on 3.0l

I think he may have meant" rpm to spare".What is the present rpm at wot all trimmed up?

right now i am currently pushing the top of the WOT rpm range.

 

[aerobat]

Re: high five prop on 3.0l

right now i am currently pushing the top of the WOT rpm range.

in this case do not touch anything because with a 19 pitch high five you will loose performance - top speed as well.

 

[eavega]

Re: high five prop on 3.0l

I think he may have meant" rpm to spare".?

Yup. I meant engine speed i.e. RPM.

-E

 

[steelespike]

Re: high five prop on 3.0l

Is the 175 a boat model or hp?
Are you guessing your rpm? Your could be risking your motors health.
Actually if you are lightly loaded with a healthy motor you should be over revving.
I agree, no high five.If your at the top of your rpm range A 19 might still pull reasonably well and give ypou a tick more speed.
Sometimes Smart Tabs carefully applied will give you excellent hole shot yet if lightly applied give good speed.

 

[micsol]

Re: high five prop on 3.0l

Is the 175 a boat model or hp?
Are you guessing your rpm? Your could be risking your motors health.
Actually if you are lightly loaded with a healthy motor you should be over revving.
I agree, no high five.If your at the top of your rpm range A 19 might still pull reasonably well and give ypou a tick more speed.
Sometimes Smart Tabs carefully applied will give you excellent hole shot yet if lightly applied give good speed.

175 is the boat model. Rpms are based off the boats tach. At 6400ft in elevation. I've never seen it rev higher but I've alway got a couple people in it

 

[tpenfield]

Re: high five prop on 3.0l

A 3.0L with a high five . . . just doesn't seem right.


Maybe a 4-blade instead :noidea:

 

[Jdeagro]

Re: high five prop on 3.0l

Unless the boat is used for pulling skiers, tubes, or wake boards constantly, I am not a fan of four and five bladed props for a few reasons.
One, the low end performance (acceleration) may improve but is near certain that the top end will suffer. In addition the boat will be more prone to have a torque list at cruising speeds.The most common way to increase top end is to increase the pitch (ie: move from a 17" to 19") but stay with the three blade. The flip side of this is that the boat performance will suffer during acceleration, especially under a load.

Supreme Mariner, suggested that the use of our trim tabs may give you more top speed. Three things will help you achieve your goal of more top speed and maintain the towing performance. One, use Smart Tabs to improve acceleration with minimal bow rise. Time to plane will be cut nearly in half. Two, move from the 17" prop to a 19" three blade. Three; MAKE SURE YOU TRIM OUT so that the prop is perpendicular to the water surface when at speed. Currently you may incur porpoising when you trim out, but when properly adjusted the Smart Tabs will eliminate the porpoising when you trim out more.

The better trim angle, increased prop pitch, and smoother ride should give you another 3 MPH or more. Fuel economy will improve as well since the engine turns fewer rev's per mile with the 19" prop and less up hill struggles during acceleration.