Cape Dory 28 repower and prop question

[SVFayaway]

I am moving steadily towards repowering #2. The original Volvo MD2 leaks oil, smokes, and is generally showing its age. It also overheated quite badly this season and though there's no obvious damage my cruising plans require high reliability and I can't be sure something won't crop up in the future. I have acquired a used Yanmar 2GM20F which appears to be in quite good condition. For anyone with a Cape Dory 28 (or 27 or 30) with a Yanmar 2GM20 what kind of prop do you have? I currently have a 14/14 2 blade which works great but I expect the new motor will need a new prop with a different pitch, etc. I can do the math to come up with some numbers but practical experience matters when choosing a prop so I'm interested to hear from anyone who has this motor in their boat. I'm also keen to hear any words of advice on repowering a CD28 generally, especially with regards to modifying the engine bed to accommodate the new motor.

[Rockinar]

Prop choice will depend on engine size and transmission ratio.


I currently have 28 a Universal M18 that has 14HP and a 1:2 transmission ratio. When I inquired with a folding prop builder they told me a folding prop wont fit my boat (correct), but for my setup they recommend a 2 blade 13x10 prop. I dont know what I currently have but Im looking into getting a new prop and would probably just order a fixed 13x10 if I cant find out what I have currently.

[mgphl52]

You may want to contact http://westbynorth.com to learn about the Campbell Sailor prop.
Five years ago I put one on KAYLA and am very pleased with the performance. We used to race KAYLA
in PHRF classes and would leave her in neutral. On some offshore races it was amazing how much
noise we got from the prop spinning! If she was shifted in to reverse (aka: lock the shaft) we would lose
at least a full knot! With the Campbell Sailor, we have not been able to hear the prop spin in neutral and
have no loss of speed when locked in reverse.

[sgbernd]

Ask your installer who he recommends and has had good experiences with. I specified a Michigan Wheel when I repowered and the installer, without telling me, installed an Acme, the smallest model they sell. He told me "That is what we are using and have had good luck with them". Acme makes ski boat props, not sail boat props, and I was not happy. It doesn't even look like a sail boat prop. He told me to use it for a bit and then if I didn't like it and he would change it. I believe he chose it because the local rep provides good support. All said and done, I could not be happier with the ACME. Engine hits red-line, boat speed tops out at 7kts, less vibration, what is there to complain about?

I did have to have the trailing edge ground to reduce the "singing" but the performance is much better than the old MW. The downsides are the fuel consumption is a bit higher than the old MW two blade,which is to be expected from a smaller diameter, steeper pitch and it is thicker which means I need to move the engine if I want to pull the prop, which will make the next cutlass bearing change a bit more painful. With the old 2 blade MW, I could disconnect the coupling and remove the entire shaft.

In my case, local support and a good installer proved the best source of knowledge so I would start there. In this case, he had done several similar full keel boats including another CD28 recently and knew what worked.

Steve

[SVFayaway]

Thanks for the input. I will look at the Campbell prop. What motor do you have in Kayla? I am doing the install myself so I'm relying on the manufacturers to do the math and make recommendations. I do like how much power my MD2 produces, but my biggest concern is fuel consumption since I'll be cruising the boat quite a bit (with any luck.)

[mgphl52]

Thanks for the input. I will look at the Campbell prop. What motor do you have in Kayla? I am doing the install myself so I'm relying on the manufacturers to do the math and make recommendations. I do like how much power my MD2 produces, but my biggest concern is fuel consumption since I'll be cruising the boat quite a bit (with any luck.)

KAYLA still has her original VOLVO MD7A. It's still running strong and I hope it will continue to! We don't do extensive sailing any longer and mostly just day trips on the bay. At least the bay is 30+ miles long!