Not sure if they still sell the Auto-prop but, at the time(about 2 years ago), they were the US/North American rep for Gori.
Never had a fixed prop but could the noise be from cavitation? Charlie Nelson Water Phantom Sent from my iPad > On Jan 14, 2014, at 5:21 PM, "dwight" <[email protected]> wrote: > > Charlie > > My Auto prop came from AB Marine…Do they still sell Autoprop and if so would > you be able to check the price for an H5 now. > > Any fixed blade prop will create more drag than a folding or feathering prop. > Most of us don’t like drag on our sailboats, I think a large percentage of > sailors want to go faster under sail and that means a folding or feathering > prop on our secondary means of propulsion, the engine. I noticed that when I > replaced a 2 blade Martec folding prop with a fixed two blade for the new > owner when I sold the boat that not only did she lose speed (more than ½ kt > under some conditions) but the fixed 2 blade prop also created an annoying > noise when under sail, sort of destroyed the tranquility sometimes but I > could always tell it was there, the boat just felt and sounded a lot > different dragging it along. He wanted the prop changed because he was a > beginning sailor and he wanted more control under engine power (while docking > especially) and I had the right fixed 2 blade prop for the system which might > have been from factory build so he made the Martec his spare. > > From: CnC-List [mailto:[email protected]] On Behalf Of > [email protected] > Sent: January 14, 2014 5:53 PM > To: [email protected] > Subject: Re: Stus-List folding prop for C&C 40 > > I strongly support what Bill and Andy said about a possible different prop. > > One other important consideration for a two bladed prop is the amount of space > between the prop tip and the hull. Most 2 bladed props will be larger in > diameter > than a 3 blade to make up for the lack of surface area in the blades for > equivalent thrust. > Depending on the prop rpm and pitch, there needs to be a certain minimum > space or the > prop may produce cavitation or otherwise interfere with the hull. > > As you will soon find out, from this list or a vendor, a prop change is > hardly as straightforward > as pulling the old and installing a different one. > > When I re-propped my 36 (from 3 blade Maxprop to 2 blade folding Gori), I had > to replace the transmission to get the reduction needed > for good overall efficiency between the motor rpm, the tranny reduction and > the prop pitch. When these are matched, it should be possible to > achieve your theoretical hull-speed at or near your engine maximum RPM, at > least in flat water and with an engine which is appropriate for > your displacement. > > I found Goeff at AB Marine (a Kiwi) to be an excellent source of information > on all of the above. > > Charlie Nelson > Water Phantom > C&C 36 XL/kcb > > > _______________________________________________ > This List is provided by the C&C Photo Album > http://www.cncphotoalbum.com > [email protected]
_______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com [email protected]
