Folding Prop - Gori 3 Blade

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Armin
Posts: 19
Joined: Wed Nov 02, 2005 5:40 pm
Location: Toms River NJ - Riverbank Marina

Folding Prop - Gori 3 Blade

Post by Armin »

Does any C350 owner have experience with the Gori 3 Blade prop under sail? How much of a speed change can one expect under sail vs a standard three blades 15 x 9 at 10- 15 k? I am interested in actual results -- not the spec sheet info, which I have. Also, any problems with cavitation? How would you rate the "overdrive" feature?

Thank you in advance.

Armin
Whitehook
Posts: 24
Joined: Wed Nov 02, 2005 5:53 am
Location: Keyport, New Jersey

Folding Prop - Gori 3 Blade

Post by Whitehook »

Hi Armin,

I have acquired the Gori folding three blade prop over the winter but haven't yet had the boat in the water. I am also interested in some real world experience. Hopefully there is another C350 out there that can comment, otherwise I will let you know later this spring.

Greg Klocek
s/v Whitehook
Chanticleer
Posts: 7
Joined: Mon Jan 16, 2006 12:42 am
Location: Tuscumbia, AL

Gori Prop

Post by Chanticleer »

Greg,
I was wondering if you could give me the specs on the gori prop you purchased. I'm thinking of changing out my stock prop for the gori as well. Did you order from AB Marine? Thanks.
Alex
PS Hopefully, I should have chanticleer out of Mobile early next month. I don't want to risk leaving her through another hurricane season.
Alex Pingree
Chanticleer
#318
Whitehook
Posts: 24
Joined: Wed Nov 02, 2005 5:53 am
Location: Keyport, New Jersey

Post by Whitehook »

Hi Alex,

Yes, I did get the Gori from AB Marine and they were very helpful. It is a three blade and the size is 16.5X11 but It hasn't been in the water yet so I can't give much of a report at this time.

Greg
s/v Whitehook #199
Armin
Posts: 19
Joined: Wed Nov 02, 2005 5:40 pm
Location: Toms River NJ - Riverbank Marina

Post by Armin »

Greg,

I fitted my Gori 3 bladed prop last week. Had to used a "substantial" hub puller to get the old prop off. The Gori instructions were fine other than the fact that they did not give a direction of view when indicating the direction in which to turn the rear sleeve. I found it to be a two person job. I'll do hope that my cavitation problem will have been solvled by fitting this prop, although I purchased it primarily to reduce drag under sail.

Armin
Armin
Posts: 19
Joined: Wed Nov 02, 2005 5:40 pm
Location: Toms River NJ - Riverbank Marina

Post by Armin »

Gerg,

Have you had a chance to try out your new Gori prop? I had my boat out for the first time after having installed my new prop. It is a 16.5 x 9 three blade. The performance was great -- no cavitation and outstanding control while backing. My only concern is that the max rpm was only 2,500 in standard mode and 2,100 in overdrive. Please let me know what you find with your prop. I am concerned that the prop that AB Marine selected for my engine is too large.

Armin
Whitehook
Posts: 24
Joined: Wed Nov 02, 2005 5:53 am
Location: Keyport, New Jersey

Post by Whitehook »

Armin,

I have installed the prop but will not splash the boat in until the end of the month. Business travel and a trip to the BVIs means that I will get a late start this year. I will be interested to hear of your discussions with AB Marine.

Greg
Armin
Posts: 19
Joined: Wed Nov 02, 2005 5:40 pm
Location: Toms River NJ - Riverbank Marina

Post by Armin »

Greg,

I will keep you advised. Give me a call in the event of questions.

Armin
Armin
Posts: 19
Joined: Wed Nov 02, 2005 5:40 pm
Location: Toms River NJ - Riverbank Marina

Post by Armin »

Greg,

At the request of AB Marine, I ran some sea trials with the Gori three blade 16.5 x 9 propeller last Sunday. To be sure I was getting a good tach reading I used a non contact hand held tach to validate the rpm reading on my instrument panel. I was pleased to note that the panel mounted tach is accurate. The max engine speed at full throttel with the prop in standard forward was 2,550 and the indicated boat speed was 7.4 knots. With the propeller in overdrive, the max engine speed was limited to 2,100 rpm. The boat speed was also 7.4 knots.

In discussions with Hanson, the Universal rep. for our area, I was advised that it would not be good to run our M35 with a "wheel" which was too large, since it would cause the engine to labor with the possible results of excessive carbon build up and valve damage.

AB Marine has been very responsive, so I hope that they will have a recommendation before you are scheduled to splash your boat. I am very pleased with the performance under sail. I would guess that the boat under sail is 8 to 12% faster.

Armin
Hans Grasman

"wheel" ??

Post by Hans Grasman »

Armin
Can you elaborate on this? I assume the "wheel" is the prop right?
That speed is great! I have the new Michigan Sail Prop installed and I still do the same speed about 6.5 with 2700 rpm in flat seas. But NO CAVITATION in rough seas and heavy winds on the nose. I am happy with the new prop.


Hans
Belcourt #165
Armin
Posts: 19
Joined: Wed Nov 02, 2005 5:40 pm
Location: Toms River NJ - Riverbank Marina

Gori Propeller

Post by Armin »

Hans,

W.r.t. your question, yes "too large a wheel" means "too large of a propeller." Because of the cavitation problem I have had since purchasing my boat, hull# 207, and because I hoped to get somewhat better performance under sail, I purchased a Gori 3 blade propeller from AB Marine last February at the boat show. The propeller which was recommended by AB Marine was a 16.5 x 9 R. The propeller is a great bit of engineering and completely solved the cavitation issue, however, the propeller is somewhat too large for the boat since the maximum rpm achievable with a wide open throttle (WOT) is 2,550 in the standard forward position and 2,100 in the overdrive position. Since the Westerbeke M35B is rated at 3,000 rpm, the propeller pitch or size must be adjusted to permit the engine to reach its WOT rated rpm. Running the engine at a lower speed with WOT places a greater load on the engine.

During the sea trials I ran last weekend in 1/2 foot seas the boat reached 6.4 knots at 1,800 in overdrive and 2,100 in standard forward. Speed under sail improved by 8 to 12 percent.

Best Regards,

Armin
"MakeWay" Hull #207
DuncanMcMillan
Posts: 49
Joined: Mon Mar 20, 2006 9:44 pm
Location: Nanaimo, BC

Re: Folding Prop - Gori 3 Blade

Post by DuncanMcMillan »

It's been a few years since the Gori 3 blades were installed. Can anyone provide any feedback on the prop or any impact on the engine? Any recommended max rpm?eed
Duncan #248
Para Handy
Ray Edwards
Posts: 18
Joined: Fri Jul 21, 2006 8:05 am

Re: Folding Prop - Gori 3 Blade

Post by Ray Edwards »

This has been an interesting exchange of comments concerning using the folding Gori prop as the answer to our prop (cavition) issues. I to had the 15x9 standard prop on my C350 (hull #293) with a severe cavitation issue anytime over 1800 rpm's with a head sea. I changed to the current 14x10 prop recommended, cavitation problem solved but boat speed dropped considerably epecially frustating was when bucking a current or tide. Had lots of other things to make my C350 comfortable to spend boat $$$ on so lived with the speed issue.
After much research over the past couple of years finally decided to ask Santa for help in replacing the now standard 14x10, know this blog has been about the Gori folding but now I'll throw a curve and bring up another prop ---- the Martec (Autostream) self feathering prop.
It is a stainless steel feathering prop, very very well built, size based on their specs for our power plant is a 16x9 with claims of using this on several 350's with great results, have asked for them to put me in contact with current users now waiting for their reponse. Might add their 3 blade folding version specs is a 15x9 because of blade and housing shape,(same size as our orginal) explanation was their blade shape is different and housing moves the blades further aft helping with water flow.
Investment has been made (Nothing is to good for the yacht "Maria") ordered at the Annapolis boat show already received but can't install until spring launch but will look good under the tree.
Anybody out there with a MARTEC or know anyone with one ----- Martec is telling me they guarantee satifaction as they are confident in this being the right fix but can't help being skeptical until proven under fire.

Ray Edwards
C350 #293
"Maria"
djones
Posts: 36
Joined: Tue Jan 22, 2008 7:03 pm
Location: Oak Island / Southport, NC

Re: Folding Prop - Gori 3 Blade

Post by djones »

We elected to put a Martec 2 blade folder on our project boat C350 #13 "Onatop"

Here is the exact type:
"Mark III Elliptic 16x12" RH two-blade folding prop for one inch shaft"

I can just reach a maximum of 3100 RPM, measured with an optical tach on the crankshaft pulley. The boat speed is very good under power with minimum drag under sail. The 2 blade isn't as smooth as the 3 blade props would be, but I was going for efficiency. I'm quite happy with this prop, and can outrun most boats under power in my neck of the woods.

One thing to get used to...this prop is simply two blades pivoting on a single cross-shaft. There is a very noticable "clunk" as the blades snap open. There is a balance between having the idle low enough to minimize the "clunk", but not so low as to get a lot of low-idle chatter out of the engine. Reverse is OK, with the normal port prop walks that most all RH props have.

Thanks,
Don Jones, C350 "Onatop", Oak Island/Southport, NC
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wcconway
Posts: 130
Joined: Sun Nov 11, 2007 1:39 pm
Location: Pensacola, Florida

Re: Folding Prop - Gori 3 Blade

Post by wcconway »

Trying to decide on a feathering or folding prop for installation this year. Any die hard opinions on which style and brand??
Wally & Coco Conway
, #467
Pensacola, Florida
leigh weiss
Posts: 208
Joined: Mon Mar 05, 2012 7:32 pm

Re: Folding Prop - Gori 3 Blade

Post by leigh weiss »

Wally and Connie,
IMHO I went with the KIWI feathering prop. It allowed me to "fine tune" the pitch to get WOT max rpm of 3050.
They have a new blade design and I upgraded. This gave me about .25-.50 knot improvement in speed. A simple change out of the blades. This can be done in the water, so I keep spare blades on hand. Until now I have not had to use them. I have pix of the install if you would like to see them.
Leigh and Donna Weiss
Brisa #155
Georgetown, MD. USA
dedgell
Posts: 39
Joined: Sun Jan 10, 2016 4:01 pm

Re: Folding Prop - Gori 3 Blade

Post by dedgell »

Wally and Connie,

I spent the winter researching folding and feathering props. I ended up with a VariProfile prop, which is a feathering design. Check out my detailed posts about my research and decision making process in the hull / prop / rudder forum (my post is titled VarioProfile Prop, which is actually a mis-spelling).

Had I decided to go with a folding prop, the Gori was at the top of my list. I chose a feathering style for its ability to fine tune the pitch and better backing performance. I'm glad I did.

No matter which prop you decide upon, my advice is to upgrade to either a folding or feathering prop. I am very happy with the performance of my boat after changing the prop. I'm most surprised about how much better the boat sails, particularly in light wind. More speed under power and better backing performance are icing on the cake.

Good luck with your prop search,

David Edgell
S/v Blue Wing
C350 #442
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