Gori props

[Kia Orana]

Does any body have experience with gori props.
We are considering add a new gori prop last quote costing approx $7000
But we would save on 1000 nautical m trip 1/3 tank of fuel ( approx 400 l ) and add extra 2 knots speed on sailing plus no wear on prop shaft while sailing.
We have steel Roberts 44 sloop powered by 120 h p Yanmar.

Cheers Mark

[valhalla360]

I think you are hearing a lot of hype. I seriously doubt you will get significantly better fuel economy while motoring (certainly not 1/3 less fuel used). Fixed props are the best option while motoring.

Most folks talk about gaining 0.5-1.0kts with folding props.

[jaybird1111]

Catamaran, two engines, two-blade folding Gori props. Very pleased with the products. At least a knot faster under sail, maybe more, when folded. Have good thrust both forward and reverse under power.

Boat came with Gori, and if they ever need replacing, they'll be replaced with Gori.

[valhalla360]

Don't get me wrong. I don't think they are bad just that the numbers quoted in the original post seem wildly optimistic.

[leftbrainstuff]

The fuel savings under power seem far fetched. We have a maxprop and see 0.5 knot or more improvement in boat speed undernsail when feathered. Lots of bite in reverse too compared to a fixed prop.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[senormechanico]

I've had fixed, then Max Prop on a previous boat.
Obvious improvement.
On my current boat which came with a Gori 2 blade, I replaced it with a Varifold 2 blade.
I took careful speed/rpm tests in flat water, no wind no current before and after the change and got the same cruising speed at 15% less rpm. Max throttle rpm is the same right at the peak recommended by the engine manual.

[valhalla360]

Originally Posted by senormechanico

I took careful speed/rpm tests in flat water, no wind no current before and after the change and got the same cruising speed at 15% less rpm. l.

If you are running a higher pitch, the RPM may go down a bit but that doesn't mean you are buring less fuel if the engine is running at a higher torque.

[senormechanico]

True, but there's less vibration and almost 1 knot higher top speed as well.

Both tests were with smooth clean bottom.

[Zanshin]

I had a Gori propeller on my Jeanneau 49DS and loved the system. If I wanted to motorsail or motor in settled conditions I'd get the prop into "overdrive" mode and run at much lower engine revs for the same speed. This really gives enormous fuel savings when motorsailing.

The downside is that it is possible to overheat the engine when in overdrive. I did this once by mistake when I was trying to get to Falmouth Harbour in Antigua before dark. I decided to install what all trucks have - an engine gas exhaust temperature gauge. This would let me run the Gori in overdrive mode and use the exhaust gas temperature to get the perfect load factor. I had the system spec'd out from VDO but then ended up selling the boat. I still have my page about the Gori at https://www.sv-zanshin.com/zanshini/zanshinigori.php

My next boat already had a folding propeller system, otherwise I would have immediately gotten another Gori.