Difference between duo prop C and F series

[Crowney]

I have a crownline 266 LTD it has a C series prop on it. My confusion is everyone that has the same outdrive on their 266 ltd runs the F7. Are the splines the same for a C series and F series? I dont want to make an expensive mistake buying a prop that wont fit.

Thanks in advance.

 

[Maclin]

Re: Difference between duo prop C and F series

They are not the same. C series are for (earlier white drives) 280DP, 290DP, DP-A. The F series are for SX and later duoprop drives.



What drive do you have? Actually it is simper than that (unless someone changed the color on your outdrive!), what color is your drive? and what color are the drives on the boats you are comparing to?

 

[Crowney]

Re: Difference between duo prop C and F series

The serial # references it as the DP-D1 outdrive. The gears are 1.78 : 1. The outdrive has been painted. It was a grey color but again not sure if that was the original or not.

Are the splines different as well? I know the F series has the exhaust through the hub of prop. The C series has a solid hub.

 

[Maclin]

Re: Difference between duo prop C and F series

Your drive can only take B series aluminum or C series Stainless steel. Well, ok, the diesels with that drive use A series aluminum.

In the next generation after 280DP/290DP/DP-x drives the whole design is different, for example the F series have thru hub exhaust. Does not matter what the spline count is, you have to have the compatible series props for the drive.

The D series is the aluminum equivalent of the F series stainless steel.

Why are you asking?

 

[Scott Danforth]

Re: Difference between duo prop C and F series

are you sure you have C series props?

 

[Maclin]

Re: Difference between duo prop C and F series

I probably should not have referred to drive color as a qualifier :redface:

The DP-D1 definitely uses A or B or C series props only. The A series is for diesels or big block high torque engines with the 1.78 ratio. B or C series works with the gasoline engines for any ratio, but for diesels the A series is mandatory. The A series has thicker blades and is overall heavier built, and the rear prop is 4 blades instead of 3.

A series is aluminum
B series is aluminum
C series is stainless steel

No other series prop will work on the DP-D1.

 

[Crowney]

Re: Difference between duo prop C and F series



I am almost positive they are C props. A bit of mineral deposits on the props by the numbers but it does look like a c series prop. Pictures are attached.

The old motor was the stock 330hp. Which on a dyno is actually more like 300 hp. My new motor on dyno is 431hp and just over 500 lbs of torgue. I am looking to get as much performance out of the boat as possible. Trying to do as much research before spending coin on a prop.

I really appreciate all the help. Looks like I just need rpm passes to see if I need to go to the C7 prop.