Sharrow Prop Manufacturing

[Midnightsun]

Considering they say there is a 50% drop in fuel use,...... well that would indicate to me that the engine is applying far less horsepower at the same prop speed which on the surface seems hard to swallow

Efficiency is coming from the prop just like one can fine tune/resize/change materials on an application for better efficiency resulting in better fuel economy. The Sharrow design implies it is twice as efficient at moving the test boat at certain speeds which I do agree is either hard to swallow or an amazing feat of engineering.

Done by boat test, I do tend to believe their numbers. With all the thousands of smaller Bayliners out there, someone would shout out the BS after paying 5 grand for a prop if it did not deliver close to what boat test claimed. The big question is, can they be repaired/balanced or does one need to cough up another 5 grand after a bad hit? Maybe paying twice the fuel cost may come out cheaper in the end.

[RGrew176]

I do find the results of the various tests interesting. Truth is my new boat with the 115 Yamaha will not be fuel guzzler but any improvement would be acceptable. There is no way I would pay 5K for one of those props but if the price came down to $1000 or less I would at least think about it.

I spoke with the Yamaha people at the Detroit Boat Show in January and they are going to manufacture Sharrow Props for their engines. Still limited to 150 HP and above no decision yet of manufacturing for lesser HP engines.

Like the test video I posted they are now making them out of aluminum too. I would like to think that would result in lower pricing. Just FYI Sharrow Props currently are being manufactured here in Detroit just a stones throw up the road from where I live.

I am keeping an open mind and will continue to observe new test videos and other information that becomes available on Sharrow Propellers.

[Midnightsun]

Like the test video I posted they are now making them out of aluminum too.

I believe the aluminum was the only material they could use at the time when manufacturing was in India and very time consuming. The new machines now allow them to make props from Stainless Steel in the USA at a much quicker rate. The new in house process should reduce the costs.

[bud37]

I wonder if they have a Canadian distributor/supplier set up yet ?

[km1125]

Source of the post

In all the tests I've seen so far, they don't get the best prop for the application and then compare it with a Sharrow, they just replace the stock one with a hand-selected Sharrow and then run the test.

In the last link posted by Rick they test a small Bayliner with stock prop and then a prop widely used by many as it helps performance so yes there is at least this test with a better prop being used. The Sharrow still puts it to shame. Jump to 2:25 on the video. The results are pretty amazing considering it got up to over double the fuel economy at planing speeds which would cut your fuel bills by over half.

It's claims like that which make me think this is more of a scam than reality.

There might really be some benefits, but when you look at the actual video in detail you can also see how they set the trim differently when they're testing the "normal" prop vs how they test the Sharrow. THAT is not a fair test, and I would NOT trust "Boat Test" magazine because they're not being an independent "authority" or they would call them out on things like that.

Is it possible to get 10% improvement? Sure. !5%? Maybe. But if you're buying 100% improvement (which is "cut your fuel bills by over half"), then I also have a bridge you should look at because it's for sale too.

[Cooler]

Boat Test runs multiple articles on Sharrow. Seems like at least every third day. They must have some sort of "interest". The info I read shows results in many areas. I have not seen 50% fuel reduction. I did see some tables show 30% reduction, so I am thinking 20% would be a real stat. That is still pretty good. Lay that over with the noise reduction, elimination of prop slip, and illustrations of how water flows through the inside loop, and that tells me there is less strain on engines. BUT, 5K is still more of a "perceived value" price. With todays manufacturing technologies, it can't cost ten times more to produce. Rick - drive over there and tell them I will volunteer my boat as a test boat. 19 X 19 counter rotating, 1.25" shaft. They have to hurry though, launch is in about 50 days. er

[bud37]

Source of the post Lay that over with the noise reduction, elimination of prop slip

Good discussion.......
Could this prop slip elimination could be the reason for the hp cut off point, I wonder. To get a directly coupled engine to accelerate/rpm up, there needs to be slip vs speed over ground I believe, ( consider what happens to an over propped boat rpm wise )....no slip might require lots of torque. This is what I can't wrap my old brain around....explain the science.....as before the boat weighs X, the force to propel this weight is X, therefore you need, X HP ....which translates to fuel use. There are no free rides when it comes to this as I see it. There may be some optimization though, but.... IMO.

Not saying this is all not possible, looking forward to the reveal...I guess we will all soon see.....

[Midnightsun]

Odd I cannot find any person such as someone on a forum that has tried one and confirms how great it is. Only Sharrow and Boat Test. Sharrow has been around since late 2018 if I read right so someone must have something to write about I would think.

[km1125]

How much prop slip is there in a correctly-matched application?

15-20% is pretty typical. If a Sharrow eliminated ALL of this (which is probably theoretically impossible) then that would result in a 17-25% improvement MAX. If you have much over 20% you likely have a mismatched prop for your application.

Now, if they eliminated a good percentage of slip - let's say half - that's still a pretty impressive improvement. That would be 8-12% percent efficiency gain, which might make it worth it for some folks. If they'd show a "bulletproof" demonstration of that, they'd get a LOT of folks onboard with it.

[Cooler]

I can't remember the prop slip stats, but I do recall being a little surprised. It was not completely eliminated, but significantly reduced to a minimal level. That article was published in Boat Test, so if there is a way to search articles, it could be accessed. It was a few months ago. I will attempt to access the links in my history to see if there is a way to search. er