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Prop location!!!

Posted: 11 Feb 2020, 09:10
by Chivs
Ahoy all, some years ago I remember reading where best to locate prop. I believe the consensus back then was to have it about a fist clearance between prop and rudder. I did this and recently posted a video of Torea running on the trailer. Steve Moritz (bit of a prop guru who has done props for Whoopi Goldberg) posted the attached after seeing the video
PS my prop is 120 mm from skeg!

Re: Prop location!!!

Posted: 11 Feb 2020, 10:12
by 4541 Andy
Hi Chivs, I have just shortened the shaft on Torquewood in the quest to lift the nose of the boat and reduce the wetted area of the hull. I only managed to remove 22mm of shaft. 120 mm seems a large distance from Skeg to prop going on the 4 boats I have sitting around here. The man you mention in your post is the same person who has advised me in Torquewoods modifications.
P.S I always thought it was a thumbs width clearance,not a fist!

Re: Prop location!!!

Posted: 11 Feb 2020, 11:16
by Wildwoody1
25 mm shaft diam set gap about 30 mm provided you have enough prop tip to Hull clearance.

Re: Prop location!!!

Posted: 11 Feb 2020, 13:04
by Chivs
Now there’s the problem!!! But what is weird the new skeg is where the old one was and the cav plate is original which dictates rudder location. I currently running a two blade prop with roughly 130 mm blades and a rough measure means I can bring it 40 mm forward before I start chopping holes in the boat?

Re: Prop location!!!

Posted: 11 Feb 2020, 18:58
by Chivs
While I’m on a roll I have messaged Bob Carter re Turbo Fire being Toreas twin, after that I looked up Turbo Fire under readers boats site on web page and there you go!

Re: Prop location!!!

Posted: 12 Feb 2020, 21:34
by screwit
Is the skeg the same shape as the original one Chris?
Some of the older ones swept back more than the new one's.

Re: Prop location!!!

Posted: 13 Feb 2020, 08:48
by Chivs
Hi Ross. Yes mate probably more swept back than original I have been communicating with Bob Carter, it appears it was possibly an old school unknown factor back in the day?? I have attached Bobs last text for info, cheers mate

Re: Prop location!!!

Posted: 14 Feb 2020, 23:06
by Darren
Captain, I am not concerned about prop to rudder, I've seen props miles away from rudders, and the boat still turns on a sixpence. (therein lies the dark art) My concern in your particular case is the support that the skeg provides to the rotating propeller, in my opinion the prop is too far from the skeg. The motivating force for your boat is literally rotating in open water.

Re: Prop location!!!

Posted: 15 Feb 2020, 15:05
by Doc
Usually 1" space back of prop to skeg. Fist width between back of rudder to front of prop. Highest point of prop to hull ,no less than 1 1/2".
Just make sure you have enough space for a prop puller! Is the prop shaft the same taper to the prop, there are two. This could be stopping the prop from being closer to skeg.
Doc.

Re: Prop location!!!

Posted: 18 Feb 2020, 15:10
by Wildwoody1
Moving a Prop position has some effect but my belief has always been that the Rake on the blades controls the angle of Hull attack.
Positive angle to raise the Bow, negative angle to lift the Transom

Wild Woody