Shaft size for a CAL 2-27

[ric sheridan]

Question. What shaft size should I be looking for to replace a standard two bladed prop on regular Atomic in a 1973 CAL 2-27? Are all Atomic shafts a standard size.

I ask because I ran across this prop for sale:


Sailboat prop.
12" long with 3/4" shaft
These ID numbers are printed on it:
RH12DX11P

Yay or Nay?

[scratchee]

I have a 2-27 with a three-bladed prop and a 1" shaft. Can you just measure what size shaft is on the boat now?

[ric sheridan]

I have a two bladed prop and it is in the water. If the shaft is 1" then does that mean the the section where the prop fits on is also 1" or does it get bigger? My shaft at the engine is 1" but the other end is the question. Did you replace your prop or did it come with three blades? Because I was assuming mine was stock with just two. Thanks for your response.

[Dave Neptune]

ric, yes it is a 1" shaft.

There are adaptors for going to a larger shaft that slip on under the prop. I have used them on many applications and the work just fine. Most are made of plastic.

I have seen anything from a 1/2" to a 1 1/4" shaft attached to an A-4.

Dave Neptune

[Dave Neptune]

ric, your prop is a 12" diameter X 11" pitch. That is a lot of prop for a direct drive which most were in the smaller boats.
I had an E-35MKII with a direct drive and ran the Indigo which was if I remember correctly was 10" dia X 7 1/4" pitch. I could cruise at up to 2500 RPM's which gave me more power than the 1700 RPM's with the old prop.

Dave Neptune