CD27 Prop Size and Pitch

[Jerry Albright]

My CD27 has a Yanmar YSB8 with a small 2 blade prop. I am considering a 3 blade prop.Can anyone help me with the "PROPER"
or stock size prop this boat was originally equiped with.
The previous owner club raced and I believe he may have replaced the original prop with a smaller one.I would be intrested in finding out the correct size for both the 2 and 3 blade props.
Thanks in advance for any info.

Smooth Sailing
Jerry



nauticalw@aol.com

[Allen Evans]

My CD27 has a Yanmar YSB8 with a small 2 blade prop. I am considering a 3 blade prop.Can anyone help me with the "PROPER"
or stock size prop this boat was originally equiped with.
The previous owner club raced and I believe he may have replaced the original prop with a smaller one.I would be intrested in finding out the correct size for both the 2 and 3 blade props.
Thanks in advance for any info.

Smooth Sailing
Jerry

Jerry,
Be careful about the "proper" or "original equipment" propeller. Cape Dory installed a 15 x 15 3 blade propeller on my CD36, and it overloaded the Perkins 4-108 engine. Using Dave Gerr's Propeller Handbook, I calculated the proper pitch to be about 10 inches instead of 15. My boatyard manager confirmed the 10 inch pitch using a propeller design computer program. I changed propellers and achieved great improvements in performance.

-Allen
CD36 WHISPER



adevans@att.net

[Warren Kaplan]

Jerry,
Previous owner of my 1980 CD27 installed a 12 X 8 3 bladed prop. Its on a 1 inch shaft. Works just fine. Of course that last statement is "relative" when going in reverse. Also, when I had my survey done the surveyor said in was a "right-handed" prop. I'm not so sure he's right about that when I see what kind of "prop walk" I get. I think its left handed. Make sure you know which yours is before installing a new prop.
Warren



Setsail728@aol.com

[Mark Yashinsky]

Prop Walkiing on a full keel boat like a CD can be different than on a fin keel boat. With so much in the way of the water flow (the keel) when in reverse, the boat "COULD" have a tendancy to turn to the left rather than the right. This could also happen SOMETIMES!!! Search the board for other threads about the walking in reverse of CD's, then go out and practice (and go sailing).

[Warren Kaplan]

Prop Walkiing on a full keel boat like a CD can be different than on a fin keel boat. With so much in the way of the water flow (the keel) when in reverse, the boat "COULD" have a tendancy to turn to the left rather than the right. This could also happen SOMETIMES!!! Search the board for other threads about the walking in reverse of CD's, then go out and practice (and go sailing).

Mark,
I figured out what my boat does in forward and reverse a while ago. Now I get in and out of a very tight slip (not much turning radius, boats close behind me, etc) without too much trouble. But the prop walk in both forward and reverse leads me to believe mine is a left handed situation rather than a right handed one. I could be wrong but I don't think so. I'll have to check the prop when the boat is hauled for the winter. In any event..left handed or right handed...nothing has been stopping me from sailing when I have the time (weather permitting).



Setsail728@aol.com

[mark yashinsky]

Did not know your knowledge of the boat and how she handles and why. Many different levels of people on the board and wanted to start off w/ the basics and work up. I apologize. Another idea. You should be able to see the prop shaft from the engine access hatch under the companion steps. While motoring and someone is at the helm or at the dock and the engine at idle and in gear, take a flash light and see which way the shaft is turning. If w/ someone, they can knock the transmission in and out of gear so you can see the direction as the shaft starts and stops. WATCH OUT FOR THE BELTS ON THE FRONT OF THE ENGINE!! That shoudl answer your question w/o waiting for haulout.