CD 28 three blade propeller

[Bill DeCamp]

Want to change my two blade prop to three blade. I need information on which props work the best, 13x13,13x12, 13x9 ? We have the standard Volvo MD7A engine 1.9 to 1 tranny with 1 inch shaft. We have owned our CD28 since 1982 had a 25 prior to that, she still turn heads after all these years!!



tocoiriverrats@aol.com

[Ken Cave]

Take your two bladed prop to a GOOD prop shop so they can make the right pitch and adjustments to make it compatable to the two bladed prop that came with the boat! Mine cost me about $350 (with all the changes) and now the engine purrs like a kitten at l800 RPM and I am cruising at 5.2 knots. The higher the RPM you will notice more noise due to cavitation-but you will go faster if you need to!

Hope this helps

Ken Cave
Cape Dory 28 #227



bcave@whaidbey.net

[Paul Grecay]

If you contact Michigan Wheel, they can fax you a questionairre which will enable them to reccommend a prop. I did that but rather than purchase the prop from them, I found a 3 blade Mich. Wheel prop at Ocean Outfitters in Annapolis for $25. It was a 13" LH prop with a pitch of 10...I discovered after one season that I still had rpm to spare (my cd 28 has a 14 hp Volvo penta MD2B)...so I had the prop pitch increased. I still have rpm to spare, but there is just so far that a prop shop can bend those blades. After alot of VooDoo, I have found that fitting a prop precisely is largely a matter of trial, error and personal preference for power, drag, etc. The prop numbers you mentioned sound right. I can say that the 3 blade prop (despite an increase in drag) is very useful. Esspecially when you are maneuvering in a tight space...it's most useful feature: you can stop the boat really fast when you need to. I haven't noticed any increase in speed (a function of the hull rather than the prop) but I can put more power into forward motion in rough seas...again, a very useful feature.

Paul
cd28 "Peapod"



Pagrecay@aol.com