1990 OMC Cobra 3.0

[widi59]

I just bought a 1990 OMC 3.0 outdrive with 15 spline prop shaft to use on my 19' cuddy setup with 3.0 engine 140hp. It came with a 14.25"*x 19P prop.
*
With*my original 1987 3.0 outdrive (overall gear ratio 1.71:1),*the WOT*is 4200 rpm with a 13"*x 19P prop.
*
What size prop would I need*to put on the*outdrive I just bought (overall gear ratio 1.86:1) to achieve the*same 4200 rpm at WOT under the same conditions?
*
*
*
*

 

[chiefalen]

Re: Cobra 3.0

17 p maybe: if i remember correctly your wot is 4200-4600 if you fall in that spread your good to go.

 

[widi59]

Re: Cobra 3.0

Would you maybe recommend 14x17p or 14.25x17p?

 

[chiefalen]

Re: Cobra 3.0

what can you get cheap ? Look on ebay always cheap props there, if you had a 13 spline i would sell you one for 35 bucks.

Seriously would not make a big difference.