new prop what do you think

[bigdaddyofhouse]

I just bought a new prop on e-bay my old one is a 15/17 on a omc cobra with a 4.3 engine.The new one prop is a 14 1/4 /19 aluminum.The boat is a 19' cuddy about 3400lbs. I had tryed a 15/17 stainless and all it did was raise my rpms about 800 to 5400 ,just a littel to much I'd say.<br /> Any guessess on the out come?<br /><br /> I'll be letting you know in about a week when it comes in.

 

[milkyway]

Re: new prop what do you think

I expect the 19 pitch to give you a lower rpm than the 17. But do you know what is the desired WOT rpm of your engine?

 

[3 Card]

Re: new prop what do you think

Big Daddy...I think the WOT is 4400-4800 RPM for the 4.3L regardless of OMC or Mercruiser outdrive.<br /><br />Generally speaking the 2 degrees of pitch (19 vs. 17) should probably drop your WOT 300-400 RPMs...<br /><br />The 14X19 will give you good hole shot but kill your top speed some.<br /><br />You could probably run a 14X21 or maybe even a 14X23 within the WOT range (assuming your tach is accurate).

 

[bigdaddyofhouse]

Re: new prop what do you think

I think 3 card is right about the rpm's 4400-4800

 

[Bondo]

Re: new prop what do you think

Originally posted by bigdaddyofhouse:<br /> I think 3 card is right about the rpm's 4400-4800

Ayuh,.....................<br /><br />I Know he's Right........... <br /><br />But,...... Props are measured in Inches,..... Not Degrees.......<br /><br />BTW,... I see a 21" prop in Your Future...........

 

[3 Card]

Re: new prop what do you think

Bondo...Yep I'm a knucklehead...my apologies