Gori propeller

[saverio]

I bought a Catalina sailing boat 350mkII model on September 2008. I decided to substitute the original propeller with a Gori propeller (model 16,5"x 12" x 3RH) on March 2011. The result was a disaster with this propeller, in fact the engine a Yanmar (model 2YM15/3YM20/3YM30) was not any more able to provide more than 2,600.00 rpm and in case of serious weather and sea conditions an adeguate power.
Gori is saying that they have supplied in the U.S.A market a lot of propellers and their several experiences with the same Catalina sailing boat, have confirmed that the propeller supplied to me is the right model.
I will appreciate any possible help in order to let me have the real experience made by some owner of a Catalina 350mkII with a Gori propeller.
Saverio Micci

[wolfe10]

Have a different prop, a 15X10 three blade Flex-O-Fold. We are a little over-propped with that.

Can't imagine a 16.5X12 three blade on a 350 unless you dropped in a 50 HP engine.

Brett

[BillBerner]

Brett -
How do you find the performance of the Flexofold with a headwind and on coming seas.
My 3 blade from Catalina stinks in those conditions.

Bill Berner
2003 C350 #66

[wolfe10]

Bill,

No prop will ovecome boat shape/engine size. Our last boat (Crealock 37') had much finer entry, max of 10'10" beam and a 50 HP Yanmar. It was less susceptible to speed reduction into a head sea. NOT a fair comparison.

The best you can do is have a prop that is properly size/pitch/number of blades and work with the HP you have.

As I said, we are a little overpitched (can't get to governed RPM), but get good boatspeed (right at hull speed at WOT), calm water and comfortably (no smoke) cruise at 6.5 knots.

Would like to try the same diameter and brand prop with a little less pitch. But that means all new blades-- NOT inexpensive.

Brett

[yodagwb]

Bill-
I have the same issue with my Catalina 14/10 and 15/9 props. From what research I have been able to do it would appear the bulk of the problem is due to the props lack of distance to the dead wood of the hull in conjunction with the weight of the boat and loading of the prop. When the heavily loaded prop deals with the disturbed water behind the deadwood cavitation ensues, of which my prop has the etching signs. In switching to a feathering or folding prop most people seem to have gotten better performance. The design of these props seem to move the blades further aft of the deadwood buy 1 to 2".

I am in need of a cutlass replacement. I intend to cut out the current drive shaft, remove the cutlass, slide the new drive shaft back in place around the rudder and then install the new cutlass around the shaft. I intend to have the machine shop cut the new shaft 1" longer than the current shaft. I also intend to add a flexofold prop which shifts the blades further aft. This should increase the distance between the deadwood and the blades by close to 3". I need to do some additional measurements as I am hoping to have enough vertical room to use a 16" prop and a reduced pitch of possible 8 degrees to off set the increased prop size.

[CloseQuarters]

I purchased and installed the 15x9 Flex-o-fold prop this spring. All seems good. Max rpm in forward is approx 250 less then max rpm in neutral. There is a bit of a "clunk" at low rpm or when you put into gear but I think I'll get used to that. Forward and reverse performance appears to be good. Looking forward to the head wind trial!
Wayne