I've got a Carver 390 with twin Cummins 315 HP engines and 4 blade 23x28 props. I recently sent in the props for balancing and the prop shop said the specs given for HP, WOT(2800), gear ratio (1.96:1) and expected speed (21 kn) didn't add up. On sea trials we achieved 2750 rpms and a speed of 40 KPH (21+ knt). Prop shop claimed that those props should not be pitched higher than 23, so they didn't do anything to them awaiting clarification on the numbers I provided on the spec sheet. It seems to me that the props were performing as expected per Carver for this hull. My question is to any other 390 owners with same engines and 23" diameter, 4-blade props, what do you have your props pitched at and what speed do you achieve at WOT?
thanks in advance
Joe
Pacific Horizons
propeller sizing
- waybomb
- CYO Moderator

- Posts: 2745
- Joined: February 5th, 2013, 9:24 pm
- Vessel Info: 1995 Boston Whaler Rage15
1987 3697 Carver Mariner
1988 Cougar 46 Kevlar Vee offshore
1969 15' Glasspar / 1967 Johnson Electromatic 85 - Location: Saint Joseph,Mi
- Has thanked: 69 times
- Been thanked: 492 times
Re: propeller sizing
2750 rpm wot with a spec of 2800 indicates a very slight reduction in pitch but certainly not to 23 from 28!
I'd leave them as they are.
I'd leave them as they are.
Thanks
Fred
1969 Glaspar Avalon /1967 Johnson Electromatic 85
1987 Carver Mariner
1988 Cougar Kevlar 46' with triple blown 572 ci
1995 Boston Whaler Rage
Past - 1988 2807, 1989 4207 Aft
Fred
1969 Glaspar Avalon /1967 Johnson Electromatic 85
1987 Carver Mariner
1988 Cougar Kevlar 46' with triple blown 572 ci
1995 Boston Whaler Rage
Past - 1988 2807, 1989 4207 Aft
- nightsky
- Deck Hand

- Posts: 67
- Joined: June 25th, 2016, 10:13 pm
- Vessel Info: '94 Carver 390 cpmy
- Location: Comox, BC
- Has thanked: 6 times
- Been thanked: 16 times
Re: propeller sizing
That is my feeling too, although I have to wonder if the stamp on the prop hub was correct at 28 pitch, and if the prop shop confirmed that my props are indeed pitched at 28. Thanks for your input.