prop test

[brianspot]

Just bought a (1992 Celebrity 2000 bowrider)
4.3LX

Had a factory 19" prop quicksilver. Picked up,
handled outstanding. Only problem was I had low rpm vibrations. I went to a prop dealership and showed them my prop. After discussing my
different options I decide to go with an apollo 21"stainless steel.
My factory prop was stainless steel as well but a 19" and a solid hub. (Output from this prop is 45mph-4800rpm. Steering is solid and very responsive in excel ing.)


This new apollo is stainless steel 21" removable hub
(This prop gave me terrible results.. I was interested in more speed. 4200rpm-40mph. And that was with a full load. So I decide to cut the load in half and see how it handled. Same results.
I am returning the prop tomorrow and possibly
going with the Mirage Thunderbolt after researchin.

Any advice?


I want to keep control, handling and hole shot. I was only trying to get more speed. But after testing out this apollo prop I am not knowing what to do.

I don't want to play this prop game.

I've done some looking on line about the prop I am using now and it seams that this prop is not made anymore. But it was with the Mirage line up. So my thinking is if I get the thunderbolt prop with the same pitch as my current prop will it give me the same results? Is there a difference in prop performance from solid hub or removable hub design.

Am I able to get more speed?

Thanks

 

[brianspot]

Re: prop test

Also, my boat weighs 2850 dry.

(And yes, the vibration went away with just replacing the prop)

If buying props is like buying tires for a car I guess the more expensive prop would make a difference.

with the (factory 19" quicksilver ...ss)
-great hole shot
-quick responsiveness
-4800/rpm
-45mph

With the new (apollo 21"..ss)
-ok hole shot. Could tell a difference
-lacked lots of response
-very loose steering.
-4200/rpm
-40mph

I'm just wanting to get more speed. But don't want to loose what the 19" quicksilver offered.

 

[brianspot]

Re: prop test

Rpm threshold for my boat motor are between (4400-4800)

 

[brianspot]

Re: prop test

Also the boat is a bowrider but has a huge Vhull. So it dives into the water.
Very nice ride though.

 

[steelespike]

Re: prop test

Calculator says that with a 1.81 ratio 4800 @ 45 mph produces about 5% slip ,an excellent number.
Do you know your ratio.or at least the hp?

 

[brianspot]

Re: prop test

That 1.81 is my ratio. I have no idea on the HP. Only know that its a 4barrel. It says it has a 262 displacement though. I have had a hell of a time trying to figure that out though. I have pulled the number off the engine and search that too. It just brings me to the merCruiser website.

It is from 1992 so I am guessing that its information is long gone. Best guess would have to be 150-210

Would you have a better idea of how to find that out?

I also agree with your comment about the slippage I found that to be true as well. I was just looking at putting more speed on her. But if I can't go up any higher in pitch because of the lack of hp and the shape of the boat. I will have to live with that. It's a great boat that looks like it came off the show room floor.

Thanks

 

[brianspot]

Re: prop test

When I put on the 21" my slip went up to 14%. I don't know if my boat can't handle a higher pitch prop or if its just the wrong manufacturer prop. If I went to a more expensive prop maybe it world make a difference. At this point I don't want to go back and forth..lol

Though curious what a 17" would do.