Toroidal propellers: gas burn reduction potential?

[ship happens]

I wanna know how it connects. They have their own hub type? How much for hub? The interest is here on my end

I would love to see this in action and compare / contrast. I'll throw down 3 props with this one on a boat that I know very well just to see what happens

 

[pescador]

I heard Yamaha is going to start offering it as an option on their motors,

 

[Birdsnest]

 

[carpeweekend]

If you look on Boattest.com, they have done numerous tests with various types of boats and the performance results are pretty astounding. Obviously, a pretty expensive fix if you hit a log versus a conventional prop. Would also like to know how well they perform in clearing weeds and kelp as is so prevalent in our waters. Despite the higher cost they would seem to be a worthwhile investment given the gas savings and ability to get to and cruise on plane at lower rpms.

Seems like they are much quieter than conventional props too. Would love to own this patent.

 

[Birdsnest]

These props at that price will need an anti-theft system.

 

[ship happens]

I'm going to phone them on Monday. I'm willing to do a boat test on this.

 

[Birdsnest]

I'm going to phone them on Monday. I'm willing to do a boat test on this.

Keep us posted!

 

[mikep]

Not really that expensive...most of the mercury enertia props are 1k + these days. Fuel is expensive. 10% on savings on 15k worth of fuel pays it off....

 

[spring fever]

Not really that expensive...most of the mercury enertia props are 1k + these days. Fuel is expensive. 10% on savings on 15k worth of fuel pays it off....

I don't think people are questioning 1500 so much as their web page which is 5000. One of our guys mentioned 1500

 

[wolf]

Whats the "true" price on these? if its 15K you would never recoup that price in fuel saving.

 

[Sharphooks]

From the guy who built my boat:

QUOTE

I know two guys with twin 300 Yamahas on their boats with those props. They love them. They get everything they advertised as far as fuel economy and noise reduction. One guy bought 4 props to get the right size figured out.

UNQUOTE

That last part worries me. That’s an expensive dialing-in process!

Promo material makes it sound like they just match pitch and diameter of existing prop but I’m sure it’s not so easy

And how do they hold up in the forest? I went through places near Hardy last summer where there was more wood then water—-those toroidal flukes look dainty like ballet slippers....one good hit and you’re in for prop wobble and leaky seal??? Sharrow says they back up their workmanship but that and fifty cents gets you a cup of crappy coffee if you’re out on the water with a busted fluke

 

[ship happens]

My understanding of fuel use reduction has to do with rpm at cruising speed. Let's just say 4000 rpm. That's a pretty average running speed for any modern outboard on a salt water application. Most the time the cruising speed when propped right is anywhere between 26 and 32 mph based on boat size, power yadi yadi ya.. Boats propped right for their intended hull speed , with correct engine height, generally don't have much prop slip while on plane. Especially when running a 4 blade. Most salt water application do for our environment. So that being said, my question and or theory is this. Does this prop allow you to move up a pitch? So that your cruising rpm is down by a considerable amount? Enough to gain a noticeable fuel economy? The pitch might actually work like a variable pitch prop in a way.

If the answer is mostly yes it reduces your rpm at cruising speed, then your putting your engine in a lower power curve. Outboards are usually rated their HP at 5 grand. With each engine class in its vintage has its own technologies throughout the years and are all a bit different on a dyno graph.. is that a good thing? Very interesting and I wanna try one

 

[Bill 310]

With the lower price,they can add in a replacement insurance coverage.

At $1500 /each ( if that was the price) purchasers would likely consider an additional $500 per prop insurance policy with an annual fee of $250/prop renewal rate.

It would be nice if their marketing department would come up with a fuel saving calculator that you could put in your own numbers

 

[CBsqrd]

Real world tests from actual users on thehulltruth.com have been far less glowing than the company’s marketing or boattest.com (which is really should be considered marketing by the company).

A couple people have posted that they saw a small increase in mpg at idle, but no improvement at any higher rpm’s when installed on their own boat.

If their claimed improvements were real, you’d would see lots of commercial users getting on board without having to market. Much easier segment of the industry to break into if you have a new and expensive product that truly delivers marginal gains. Some what skeptical that they are starting off by targeting recreation users.

 

[Sharphooks]

For what it’s worth I heard from a boat builder this afternoon that two of his guys with twin F300’s stepped up and got the results Sharrow claims, although one of them had to try multiple props to get the better fuel burn —-he didn’t say if Sharrow provides different pitches/diameters so a prospective user can dial in the top performance Or who pays for the trial and error

He also mentioned Sharrow is coming to his facility in the next few months to prop an F425—-5K downpayment to show up, 15K for the prop....I almost spat out my coffee on the 15K part of that

So to prop a Merc 600 it’s ....take out a second mortgage on the house of cash-in your daughter’s college education fund? Ha ha

I considered a pair for my DF300’s but I don’t want to be the lead goose in the “V”—- need to see more numbers and most of all, I’d like a report on durability of those dainty looking flukes in PNW waters

 

[BC Coast Pilot]

My understanding of fuel use reduction has to do with rpm at cruising speed. Let's just say 4000 rpm. That's a pretty average running speed for any modern outboard on a salt water application. Most the time the cruising speed when propped right is anywhere between 26 and 32 mph based on boat size, power yadi yadi ya.. Boats propped right for their intended hull speed , with correct engine height, generally don't have much prop slip while on plane. Especially when running a 4 blade. Most salt water application do for our environment. So that being said, my question and or theory is this. Does this prop allow you to move up a pitch? So that your cruising rpm is down by a considerable amount? Enough to gain a noticeable fuel economy? The pitch might actually work like a variable pitch prop in a way.

If the answer is mostly yes it reduces your rpm at cruising speed, then your putting your engine in a lower power curve. Outboards are usually rated their HP at 5 grand. With each engine class in its vintage has its own technologies throughout the years and are all a bit different on a dyno graph.. is that a good thing? Very interesting and I wanna try one

Some type of prop calculator is in order I think, I use rhe merc one and it's pretty good, I run Eco Enertia now but have rev 4"s and mirage plus also. That being said when I switched to Eco Enertia it was very close. Wouldnt want to buy 2 sets

 

[seabeyond]

Some type of prop calculator is in order I think, I use rhe merc one and it's pretty good, I run Eco Enertia now but have rev 4"s and mirage plus also. That being said when I switched to Eco Enertia it was very close. Wouldnt want to buy 2 sets

I run a set of the eco enertia props too. Been happy with my set. What's the review on those versus the rev 4s. Did the rev props do anything better?

 

[BC Coast Pilot]

I run a set of the eco enertia props too. Been happy with my set. What's the review on those versus the rev 4s. Did the rev props do anything better?

More Stern lift and a better top end with a rev 4 but a higher fuel burn. I mostly run the Eco because of the economy which is 30% over a Mirage

 

[ship happens]

There's most definetly alot of good props right now. It's hard to compare apples to oranges unless you go down the rabbit hole on one specific boat for actual comparisons. It's really tough to compare. As of right now my best prop is the cyclone 4 blade. But there's many props I haven't put up against that one. It's all fun

 

[Brando]

Interesting design for sure, feel like many boats are propped incorrectly and don’t even know it. Hard to believe there is that much improvement to be had but with todays fuel prices anything helps.