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folding prop

steven

Sustaining Member
anyone have experience with a Gori folding propeller ? (Is there a thread on it - I remember there was one on Indigo props.)

and by the way, is the A4 a LH or RH rotation?

thanks

--Steve
 

R.Cade

New Member
Gori

Hello Steve,
I'm quite familiar with the Gori propeller as I work at Rigworks, Inc. here in San Diego and we carry them. All in all, they are awesome propellers. Gori manufactures a 1, 2 and 3 blade prop. The 1 blade design is ideal for minimal drag although the 2 blade design actually reduces drag by 35% when compared to a standard prop. A huge advantage that the 3-blade prop has is it's overdrive function. You can control the pitch and profile by regulating your boat's shift's and throttle control. This gives you same boat speed at lower RPM's. Also vibrates the boat less.To set it in overdrive all you have to do is put the boat in reverse until you start actually going backwards, set it to ahead again and boom there ya go.

Hope this helped,

Riley
 

u079721

Contributing Partner
Hello Steve,
I'm quite familiar with the Gori propeller as I work at Rigworks, Inc. here in San Diego and we carry them. All in all, they are awesome propellers. Gori manufactures a 1, 2 and 3 blade prop. The 1 blade design is ideal for minimal drag although the 2 blade design actually reduces drag by 35% when compared to a standard prop. A huge advantage that the 3-blade prop has is it's overdrive function. You can control the pitch and profile by regulating your boat's shift's and throttle control. This gives you same boat speed at lower RPM's. Also vibrates the boat less.To set it in overdrive all you have to do is put the boat in reverse until you start actually going backwards, set it to ahead again and boom there ya go.

Hope this helped,

Riley

I've heard of two, three, and four blade props - but a one blade prop?
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
No one-blade shown on their site.
http://www.gori-propeller.com/index.asp?ID=86

Trivia: a NA I used to know argued that a one blade prop was theoretically superior because the single blade was always operating in undisturbed water. Balanced by a knob of counterweight, IIRC.
I imagine that the off center torque from that single blade was way too hard on the shaft support system in actual use, however.

Loren
 

toddster

Curator of Broken Parts
Blogs Author
There was a very small one-blade folder on a project boat that I looked at. I was never quite sure if that's what it was supposed to be, because the strut was also broken and there was fishing net wrapped around everything. :rolleyes:
 

windjunkee

Member III
I actually bought one for Voice of Reason and had to return it. It was a great concept but even the smallest 2 blade they made was too big to fit between the cutless bearing and the rudder. I ended up exchanging for a 2 blade feathering max prop.

Jim McCone
Voice of Reason, E-32-2 Hull #134
Redondo Beach, CA
 

Lucky Dog

Member III
In the world of human power water vehicles, one blade props were thought of as the perfect solution for slow rotations. Balance was the problem.
 

Slick470

Member III
I went through a new prop buying exercise this past fall to replace our martec elliptic. I went with a Gori 2-blade folder. I wish I could tell you how well it performs, but it is still sitting in our basement waiting for me to install it. It really is pretty though.
 

toddster

Curator of Broken Parts
Blogs Author
FWIW, I came up with a couple of pics of that one-blade prop that I saw, unfortunately, there are no clear direct shots of it. Looks pretty minimalist and slick. No idea on how well it works though. This was on a Ranger 28.
prop2.jpgprop1.jpg
 

Mort Fligelman

Member III
This is strictly a FWIW piece of trivial nothing....

I have had two blade Martec folders on my last four boats going back to 1970.......YUP...I'M THAT OLD

On my three prior boats I called Walt Beck and he recommended the correct size and he was always spot on.....they worked flawlessly.....on my last boat I spoke to his son Gary and learned of Walt's passing......not a problem as his pick is the proper size for my 35-3 and I am as happy as can be.......

I am sure that the other props will do the job, and maybe a bit better, but I would be hard put to justify the difference in costs.

As I said...FWIW
 

Slick470

Member III
Mort, I've spoken with the Martec guys at several boat shows. They are always friendly and helpful. I agree that their pricing is hard to beat and that the martec prop is simple and effective.

I found in my research that the benefits to a geared folder may outweigh the price difference and that taking advantage of boat show pricing, the difference wasn't that much. As I noted earlier, I haven't installed the new prop yet, so it remains to be seen if I went the right way. My biggest complaint on our Martec was that it is undersized for our boat and the performance suffered because of it.
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
Watched their on line video.... now feeling a bit confused about the "overdrive."
The major reduction in RPM's (for smooth water, one would kinda presume) would also move the engine output way down out of it's peak power curve. Wouldn't it?

:confused:

Loren
 
Last edited:

Mort Fligelman

Member III
Addendum to my post

Mort, I've spoken with the Martec guys at several boat shows. They are always friendly and helpful. I agree that their pricing is hard to beat and that the martec prop is simple and effective.

I found in my research that the benefits to a geared folder may outweigh the price difference and that taking advantage of boat show pricing, the difference wasn't that much. As I noted earlier, I haven't installed the new prop yet, so it remains to be seen if I went the right way. My biggest complaint on our Martec was that it is undersized for our boat and the performance suffered because of it.

Sorry....this should have been mentioned.....

When I spoke to Gary I had advised him that my boats up to that time had always been in fresh water, and other than a bit ot slime and grass there was nothing to impede the blades from opening, but since the new boat was going to be in Florida famous for all kinds of fouling I wondered if the geared prop might not be better....

His advice was to forget the geared prop, as any possible growth in the gears might impede the blades from fully opening......

I felt he deserved a gold star for putting integrity above salesmanship......

Since the boat is now in fresh water this completely vanished from my memory....

As I said before.....FWIW
 

steven

Sustaining Member
Gori is suggesting
11.5" x 8 2 blade folding. I think the original factory prop is 12x7 (?). Is that close enough that I would expect about the same performance (in forward) ?
 
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