More Performance Possible?

[hwsiii]

Re: More Performance Possible?

Dave, exatly which make and model of the Solas prop are you running right now.


H

 

[carolynrose]

Re: More Performance Possible?

I just got back from the boat and was ready to post when I saw your question. We are currently running an Apollo MWC993052 14 3/8 x 15 SS Prop, I had mistakenly called it a Solas in an earlier post.

Now the good stuff. I have been at training recently so have not been able to go boating since I last posted. Today we went down and I changed the prop in the water, no problem. I could not believe the amount of growth from the recent non use!

On the way out through the canal we faced the wind at 10 - 15mph against the tide.
2500 rpms - 9 mph
3000 rpms - 11.5 mph
3400 rpms - 14.5 mph came up on plane
3700 rpms - 19.3 maxxed out and trimmed
Went out to a bumpy bay and road around and fished. The good news is the boat did not dig in or struggle to get on plane. It's kind of hard to describe but the boat road very level and steady with the transistion to plane very smooth, nice for a change. Kinda like a smooth push.
On the way back in with the wind from behind about the same with the tide.
3950 rpms - 23.5 mph trimmed as best I could get.
All the crew agreed that the boat road more level and smoothly. In the roughness of the bay it held its speed much better, there wasn't that constant adjustment of the throttle needed. This prop seems to make the boat struggle a lot less. What do you recommend to do with the pitch to tweak it out, we really like the low to moderate performance.

 

[carolynrose]

Re: More Performance Possible?

Forgot to mention that we changed the prop to the Volvo QL you recommended. Dave

 

[hwsiii]

Re: More Performance Possible?

Dave, the problem now is just what I had said before, we need the prop repitched to 13". That will bring it up to the correct RPM and make it feel and run better than it does now. The performance will be enhanced, but the bottom needs to be perfectly clean NO GROWTH. You barely have the horsepower for the boat certainly not for any extra drag of any kind.
But, we need to know that the shop that repitches it has the correct pitch block so the prop will have the same blade geometry when they do it.

The only thing I can come up with is to buy a Volvo Penta 15 x15 QL 4 blade and if it lowers the RPM too much have it repitched to a 13" pitch, that is it.

H

 

[carolynrose]

Re: More Performance Possible?

OK, just double checking with you on the pitch. Now I need to find a reputable prop shop. I've already spoken to the marina about a haul out and clean off.

You were dead on about the 4-blade lift on the stern, it is amazing how much higher it lifted at all speeds. The thing that really bugs me is the amount of money I've spent on props that were "meant for the boat". When I looked at the online stores selling props for my "needs" most of the props started at 15 pitch and went higher. How come nobody seems to be selling the 13 pitch props that boats of this size and power seem to need? It's not like there aren't that many of this combo around.

Thanks for your help and I'll keep you informed when I get it re-pitched.

By the way I used to fish off the old Pascagoula Bridge when I was stationed in Biloxi in the early 70s.

 

[hwsiii]

Re: More Performance Possible?

Dave, I run an apollo ss on my flats boat, and most people would consider that the wrong prop. But with the setup I have with my boat it is great. For your particular boat with very limited horsepower it would be real hard to pick a prop that would be worse.
When you get the QL repitched to a 13" pitch you will not need to increase the size of your trim tabs, it will help to make them a little bigger but quite frankly not enough to make it worthwhile to do, in my opinion.
When I was a kid I fished it many times myself Dave.


H