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CNC props?

Posted: Thu Feb 11, 2016 12:39 pm
by EWRice
My "project" that I picked up last summer needed some major help, but that is a story for another day. One of the issues was the props. The had been butchered (repaired) many times, cut down and welded, etc. Basically, not worth doing anything with them them except hanging on a wall. After talking to my prop guy, and having him look at the boat, he suggested I look into the Acme CNC machined props. I read a review written by a Marinette owner who used them and had all good things to say.

Has anyone here used these props before? I will be trying mine this summer and will post any performance difference I see. I was able to go an inch smaller on the diameter because of the extra blade area. We will see what happens.

Re: CNC props?

Posted: Thu Feb 11, 2016 2:57 pm
by jmonday
What material? you should see an improvement if the same material is used.

Re: CNC props?

Posted: Thu Feb 11, 2016 5:04 pm
by EWRice
They are listed as Nibral, which is like bronze but softer, more springy, and easily welded and repaired. These are the same type of props you see on newer ski boats and high speed cruisers. My boat easily hits 33mph (gps) @ around 3900 rpm, and cruises good at about 21 mph @ between 2700 and 2900 rpm. They tell me that my mid and high end speed should improve because of less slippage and slower blade tip speed.

Makes sense. If you set the old prop on top of the new, you can see a lot of brass from the new prop in the air space between the blades on the old one.

Re: CNC props?

Posted: Thu Feb 11, 2016 7:49 pm
by javalin390
Interesting. What's the size? How many blades do they have?

Re: CNC props?

Posted: Thu Feb 11, 2016 8:32 pm
by EWRice
13x9 with a .080 cup and 3 blades. These were tested on a 32 marinette (don't remember the year) and out performed the 14" 3 blade that was factory. I don't remember the pitch of the old props. They are now my spares and are in the boat. I want to say 14x11.

Re: CNC props?

Posted: Fri Feb 12, 2016 7:33 am
by Tranquilo
I need to know more... My prop is too big and ebay is elusive