proper prop for Cape Dory 28 Open Fisherman

Discussions about Cape Dory powerboats and how we use them. Got questions? Have answers? Provide them here.

Moderator: Jim Walsh

Post Reply
jay crumbie
Posts: 3
Joined: Aug 13th, '22, 20:17

proper prop for Cape Dory 28 Open Fisherman

Post by jay crumbie »

Hi Members,
Recently purchased a 1988 CD open fisherman with hardtop. Boat listed at 17 kts and did so on sea trial. Reading specs on boat, I've learned that it is advertised by CD at 23-25 its with Diesel engine of 200 hp. Mine was upgraded with a Volvo Penta KAMD42P with 230 HP.
I'm currently running an 18-20 prop and WOT is a bit over 4100 rpm. Listed WOT for that engine is 3900-4100.
Please, if there are any of you that have experienced a better speed with different props, let me know. I've read that the current sped of 17 is the "normal" accepted speed but am just trying to educate myself as to what YOU are experiencing. If the accepted top is 17kts, I'm fine with that.
I believe my weight is about 8200 pounds with hardtop. Bottom is immaculate! fuel is about 80 gallons. Water is 20 gallons.

So, what are YOU using for a prop and what are your results.
is there a listed performance curve out there?? such as at 1200 rpm I can expect 7kts at 2 gph.
1500 rpm 10kts at 3gph. etc?

have anyone installed trim tabs on this 28 open fisherman? Results? Problems? Type? Cost? Worth it?

Thanks so much for you guidance. The boat (Last Command) is in San Diego. Everyone who sees it loves it! it's a rare boat out here.

Jay Crumbie
Carl Thunberg
Posts: 1308
Joined: Nov 21st, '05, 08:20
Location: CD28 Cruiser "Loon" Poorhouse Cove, ME

Re: proper prop for Cape Dory 28 Open Fisherman

Post by Carl Thunberg »

Welcome to the Board! This is the first post from an Open Fisherman owner. For what it's worth, I have a Michigan 20-16 on my Cruiser. You have a much bigger engine than I do.
Last edited by Carl Thunberg on Oct 11th, '22, 10:34, edited 1 time in total.
CDSOA Commodore - Member No. 725

"The more I expand the island of my knowledge, the more I expand the shoreline of my wonder"
Sir Isaac Newton
jay crumbie
Posts: 3
Joined: Aug 13th, '22, 20:17

Re: proper prop for Cape Dory 28 Open Fisherman

Post by jay crumbie »

Thanks Carl! Appreciate your input.
J
User avatar
gonesail
Posts: 234
Joined: Jun 22nd, '19, 16:39
Location: CD30 MKII FLORIDA

Re: proper prop for Cape Dory 28 Open Fisherman

Post by gonesail »

a guy on cruisers forum said he went from an 18 to 16 pitch in his CD 28 and actually gained hull speed. could not find the original post though.
jay crumbie
Posts: 3
Joined: Aug 13th, '22, 20:17

Re: proper prop for Cape Dory 28 Open Fisherman

Post by jay crumbie »

It was me that went from an 18/20 to 18/16. Appreciate the input.
Post Reply