hwsiii

[carolynrose]

Well I finally got out today. Ran the boat with the original 391536 prop. If you remember I had mentioned that this prop was pretty chipped up, so I ground off the edges and sanded them some.
Into the wind and against the tide:
1400 rpms - 5.3 mph
2000 rpms - 7.7 mph
3000 rpms - 9.3 mph
3500 rpms - 12 mph
3700 rpms - 17 mph
4500 rpms - 21.5 mph
With the wind and tide
4000 rpms - 19.5 mph
4600 rpms - 25 mph
Slowly falls off plane below 3700 rpms and 16 mph.
I was unable to try the Vortex 15.25 x 15 because the new hub kit washer would not slide all the way down the prop shaft.
Dave

 

[hwsiii]

Re: hwsiii

Dave, ask the prop shop to put a 1" theoretical cup on the trailing edge of the prop. This will help hold the stern up more and hopefully will increase the speed a couple of MPH.


H

 

[carolynrose]

Re: hwsiii

My two concerns with this prop are. In my repair manual it lists WOT as 4200-4400 rpm and I'm hitting 4600, and I know it might go another 100 if I kept it full throttle longer. It steers like crap at docking speeds. The 4-blade you had me try steered great but just wouldn't let me reach WOT specs.
Is it possible to find another prop that would get me into the rpm comfort zone a couple hundred rpm lower and maybe have a little more blade for low speed steering.
Or am I just looking for too much. Dave

 

[hwsiii]

Re: hwsiii

Dave, you are not asking for too much, the problem is the 13" pitch we need for your boat. If we changed one of the gears in your lower unit we could then use a 15" pitch stern lifting prop.
By putting cup in that prop like I was talking about it will lower the RPM and increase the low end speed some, but you really could use the extra surface area of a 4 blade prop.


H

 

[carolynrose]

Re: hwsiii

I'll get it cupped and see how it works. I guess it's just the nature of the beast that I'm dealing with. Now if we could only convince a prop manufacturer to build that 13" pitch 4 blade.
Just for curiosity I've been looking at the 16" x 13" and 16" x 14" ( I think they're Black Max). Is that too much blade to swing or not the right idea?

 

[hwsiii]

Re: hwsiii

If they are black Max's the should be regressive pitched and the larger diameter helps and they should only have about a 5 degree rake so they are theoretically better than what we have, but give me a couple more days.


H

 

[carolynrose]

Re: hwsiii

OK, thanks, Dave

 

[carolynrose]

Re: hwsiii

I was just doing a little bit of research. The propeller is a QA2004X Quicksilver Black Diamond 16 x 13 and it is also listed on the iboats propeller site for my application.
When I was researching this it was listed on another prop site as an identical prop to the Mercury Black Max of the same size. Dave

 

[carolynrose]

Re: hwsiii

Any luck yet? Dave

 

[hwsiii]

Re: hwsiii

Dave, I am sorry, I have been playing phone tag all week with a gentleman to see about changing the pitch on your 4 blade prop with no luck yet. I have never had a prop shop say they couldn't change the pitch of a prop by 1" before, if they have the right pitch block for it.


H

 

[carolynrose]

Re: hwsiii

I just got back from trying the Vortex 15.25 x 15 (992002). Here are the results.
1400 rpms - 5 mph
3000 rpms - 7.2 mph
3500 rpms - 9.8 mph
4000 rpms - 11.7 mph
4500 rpms - 12.9 mph
Could not get the boat on plane against or with the tide. This prop obviously is not going to work for me. The unusual thing was that there was so much turbulance at the back of the boat you'd swear we were running a prop with a diameter of 8 feet. Unbelivable.

So far our best results have been with the original 391536 15.5 x 13.
4000 rpms - 20mph
4600 rpms - 25 mph

Quicksilver Black Diamond AQ2004 16 x 13
Solas Amita 2511-155-13 15.5 x 13
Michigan Match 011016 15.5 x 13
Propco JR213SP 15.75 x 13

Would you recommend one of the above or Options (other than above)
Definately need the best stern lifting prop

 

[hwsiii]

Re: hwsiii

Dave I need to know what town you live in and which prop shop you brought the Solas Amita to.


H

 

[carolynrose]

Re: hwsiii

The prop you sent me to have repitched was the Volvo QL 4 - blade 14.75 x 15 (41102331). I live in Medford, NJ. I took the prop to South Jersey Marine Outlet in Maple Shade NJ. They told me that the prop blades were too thick to re-pitch.

The 391536 I figured I would just find the best replacement for because it is so nicked up. So far this is the one that worked the best out of the four I have tried. Dave

 

[hwsiii]

Re: hwsiii

I am sorry Dave, I tried to use the Solas but I ouldn't find one for your motor, I just have a good many threads going and it is hard to remember everything about each one. I am going to make some calls today and see what I can find out, hopefully I will have something by this afternoon.


H

 

[carolynrose]

Re: hwsiii

While we are dealing with this 4 blade prop adventure. I realize this may take some time to do. I would like to optimize what I've got now.

Keeping in mind I would like the prop with the most stern lift, which of the following props would you consider to be the best match to replace my 391536 OEM 15.5 x 13

Solas Amita 2511-155-13 15.5 x 13
Quicksilver Black Diamond QA 2004X 16 x 13
Michigan Match 011016 15.5 x 13

 

[hwsiii]

Re: hwsiii

Dave, Atlantis Propellers in Mount Laurel says he can take 2" of pitch out of that prop for us with no problems. He also said they had done plenty of these props and they actually use a prop scanning computerized machine to verify that it is right.

Atlantis Propeller Inc.
111 Gaither Drive
Mt. Laurel, NJ, 08054
Contact: Tom Slager
Toll Free: 866 349 7767
Ph: 856 231 0106



H

 

[carolynrose]

Re: hwsiii

Thanks, I'll give him a call tomorrow. Dave

 

[carolynrose]

Re: hwsiii

Well, here it is three weeks later. Got the prop re-pitched by Atlantis Propellers, that only took a week. But since then the weather has been crappy. Got out Saturday only to have the fog roll in and had to come back 4miles at 5 mph with only the GPS as our eyes, pretty scary. I got some partial results for you and hope to get a full test this week.

1000rpms - 3.6 mph, good docking control with the 4 blade
1500rpms - 5.0 mph, good through the no wake areas without the usual ton of wander
3500rpms - 15 mph and up on plane easily
4000rpms - 20.5 mph
4400rpms - 22.6 mph

The prop helped the slow speed docking and helped keep down the wander at slow speed (we spent a great deal of time at that speed coming badk in)
The boat came up on plane easily and smoothly and held it easily even through the ups and downs of the swells. Very happy with the prop. Hopefully we can get some more running time this week. I'll keep you posted. Thanks again, Dave

 

[hwsiii]

Re: hwsiii

I am very glad it is working better Dave, and I am happy it helped with some of the problems.


H

 

[carolynrose]

Re: hwsiii

It's been several weeks since I posted because its been several weeks of bad weather. Finally got out yesterday and the weather was perfect. Got to really shake the boat out. With 1-2ft seas and about 10mph wind got 27mph on the way in at 4400rpm.

What's amazing about this is the boat handles great at slow speeds and is on plane at 15mph and around 3500-3600. I thought we would lose a little top end with the 4 blade but we actually picked up a couple. I believe we could almost hit 30 on a flat calm day.

Thanks again for all your help. You definetly have the prop voo-doo.
Dave