Attn: CD27 owners with 3 blade props

[R. Meigel]

Would appreciate hearing from CD27 owners with 3 blade props:

(1) What kind of prop do you have - make, size, pitch?
(2) What engine horsepower do you have?



RLMeigel@aol.com

[Paul Grecay]

Props are a difficult problem to get a straight answer on because of all the variables. I agonized for a long time when I switched to a 3-blade on my CD 28. Finally I bought a three blade michigan wheel prop for twenty dollars at a used equipment place in annapolis (they happened to have one that fit and "seemed right". My engine is a 24 HP volvo penta with a 1 inch shaft. The prop is 14" diameter (Left Handed) and had a pitch of 6 (i.e. moves through 6 inches of waterfor every revolution...actually, this is only a theoretical assumption...if the prop were drilling through a thick colloidal semisolid, it would make six inches...in fact this doesn't occur in water but that is how pitch is measured). This prop worked well, but to be sure, I contacted Michigan Wheel...they can fax you a questionnaire to fill in (draft, type of boat, beam, loa, engine...etc. etc.) and they will run the numbers and make a prop reccomendation. As it turned out, they reccommended a prop of the same pitch but with slightly smaller diamter (they suggest 15% clearance around the edge...all CD's of 27 and 28 feet however, seem to have 14" props). They reccomended 6 pitch, but I found that my engine was capable of exceeding max reccomended rpm...meaning that I had "power to spare". So I had the prop repitched to 10 and now I have lots of push...it is comforting to throttle up and see that big prop wash propel me forward or backward....esspecially welcome for stopping the boat. Naturally, there is an upper limit of boat speed and more pitch does nothing for that...but in heavy sea, the extra power is used to overcome the tendency to be blown down.

Bottom line...contact Michigan Wheel...they will reccomend a good three blade prop...try it for a season and if you have engine power going unused, pitch the prop up. I am very happy with three blades...it is true that there is a slight loss in sailing speed, but there is a big gain in safety and manuverability in currents and crowded harbors. Besides is I wanted speed, I wouldn't have a sailboat...and if I wanted a speedy sailboat, I wouldn't have my trusty cape dory. Hope this helps.

Paul

Tradewind
Lewes, Delaware



rfurman@dmv.com