Cal 29 prop size

[Waltthesalt]

I’m repowering from the original A-4 to a Beta 16. This requires a prop replacement as the diesel that turns at about ½ the A-4 rpm. Can I use a 12 in dia. prop?

I’ve assumed a 12” prop is the standard installation for these boats. The measured clearance to the hull from the shaft CL is 6 ¾” MWC and Gerr’s Propeller Handbook want a blade tip clearance of at least 15% the prop diameter. That would mean an 11” diameter prop or less.

Is anyone out there having any problems with a 12” prop on their Cal 29?

[SeahorseUSA]

I will find out since I just purchased a FlexOFold 12x7RH folding 2 blade prop. Looks like it will be ok since the folding prop hub takes the blades about a inch further aft of the end of the prop shaft.

I have been using a 10.5 inch 3blade fixed prop for the past 3 years and has been very powerful with the old Atomic 4 engine with the 1:1 drive. A real drag though since I race.

I have a question. Do you know or could you point me to someone who knows the Outside diameter or the Cutless Bearing?

Thanks
Chris
Cal 29-1 - 1971
Lake Erie Sailing

[Waltthesalt]

Google Cal 29 at richard anderson's page under cal 209 ; http://www.richardanderson.net/ he has the design diagram for the cal 29 strut with the specifications. Hope that helps. When I pull my boat i can get a measurement but that wold be not for a few months.

[tommays]

12 X 8 is the original prop size and plenty of room

What you need will be a bit of voodoo as my 12 X 7 flex-o-fold is MUCH bigger than the 12 x 8 sailor

And the gearing has funny effects as the 12 X 7 flex-o-fold is a tiny bit big in forward But with the very small A4 reverse gear reduction is prefect and i think i do more knots in reverse