prop suggestion?

[jd_1598]

I have a few questions hopefully I can get some info I have a 1989 Wellcraft 192 classic cuddy,4.3 175hp OMC
out drive weight 2550
current prop; no name aluminum 141/4 x 21 serial number 391202.
It takes for about 5 seconds to plane and 20 seconds to top speed of 40 mph by speedometer and a GPS the tach is at 4600 RPM, the RPM range for my set up is 4400-4600. looking for better hole shot and better top speed, more efficient SS prop. New to iboats (this is great forum) and this is my first boat, cruisen, tubing and skiing are on the agenda probable always have 4-5 people on board. I have been looking at the Lexor SS 21p or the Stiletto Advantage II 21p, if you need more info please let me know.
thank in advance.

Jim Moshier

 

[WillyBWright]

Re: prop suggestion?

I'm not sure what the specifcs are for those props. What you need is a sterndrive-specific prop. Those produce stern lift which can help plane back-heavy boats better than those made mostly for outboards. Outboard props are more concerned with bow lift.

 

[jd_1598]

Re: prop suggestion?

WillyBWright,
thanks,that makes sense, but how do you know if it is a sterndrive prop or a outboard prop ?

 

[Silvertip]

Re: prop suggestion?

You might want to consider Smart-Tabs (trim tabs) which are a great benefit on stern heavy boats. The really help hole shot and may provide some speed increase. They definitely help handling and ride. Here's my take on the prop. Since your RPM is very near the upper end of the RPM band already, more pitch (as well as a more efficient prop) will lug it down and make things worse. Less pitch will help hole shot but cost some speed. So I think you are on the right track but I feel a 20P in stainless three blade (if available) might be a better choice. The Stilleto gets good reviews. Before spending money on props and tabs, make sure the engine is in good mechanical condition. (compression) and that it has been properly tuned and operating properly. No prop can compensate for a poorly performing engine. Speedometers are notoriously inaccurate so you may want to borrow a GPS to check actual speed. You might also want to investigate the hull to make sure there is no water soaked foam or trapped water anywhere.

 

[jd_1598]

Re: prop suggestion?

Silvertip,

Sorry I forgot I Installed Smart-tabs at the end of last year and that alone made the boat a lot faster to plane and better at slow speed less plowing. My speeds I should have up dated were with a GPS, and the engine is in very good mechanical shape. I thinking that I'm have more problems with prop slip.

thanks for your help

Jim Moshier

 

[Tail_Gunner]

Re: prop suggestion?

Been there done that on a Wellcraft, but looking at your spec's id say may a 18p Stilleto bay pro 11 Very smooth lot's a midrange punch and hole shot, The 3 blade stilleto will give more speed but not as much lift there not as smooth and probably only 1-2 mph faster. One thing to note Precison will allow you to trade up or down in the LINE of prop's you purchase, so you could try a 20p 4 blade and fade to a 18 or a 20 p 3 blade and again go back to a 19........... anyway's good luck.

PS: you might want to see if your tach is spot on, it may cost a few dollar's but prop's and shipping can be expensive and a 100 or 2 rpm can mean a real difference.

 

[jd_1598]

Re: prop suggestion?

Tail Gunner,

Can I assume you had/have an Wellcraft boat? which model ? Which prop worked for you and why? With the Wellcraft after installing the Smart tabs ...It made a big difference in getting to plane, and I can recommend them. A stilleto bay pro II is a 4 blade prop? How many R's do you lose with a 4 blade over a 3 bladed prop? As I have a 21p prop now and if I go to a 18p my rpm would go up quite a bit. You noted that precision will allow me to trade up and down ...is that even if I purchased the prop here on iboats or from them directly?

thank you
Jim

 

[jd_1598]

Re: prop suggestion?

thanks for your help guys......still looking for some help
Anyone else have some input and or info for an educated guess on which SS prop to use. How do you figure prop slip? Does 40 mph out of a 21p prop at 4600rpm sound about right?


thank you in advance

Jim