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Originally Posted by wpearch
just pick up 2 14.5x19 one ss one alum used 95.oo for the pair
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Did you take a look in prop survey posts a few threads down?
The main thing is you do not want to lug the motor, otherwise it will die a premature death. Try to prop it to run 5300-5500RPM's WOT. More RPM's are O.K, as long as you don't run it at those higher RPM's. WOT below 5100 is lugging. It will perform best at all RPM's, and have the longest trouble free life, when it is properly setup at WOT RPM's.
With a 19 pitch on that motor, in our V's, you will be pushing things close to lugging. For that motor on a V, a 17 pitch is best all around, followed closely by a 15 pitch as second best choice, and last choice would be a 19 pitch.
SS will usually give you a couple hundred more RPM's than alum, (in most cases), but other things like cupping factor in that can change all that.
Here, an OMC 15x17 SST II runs 5300 to 5400 RPM WOT, at around 43MPH.
EDIT: Just confirmed numbers, and my mistake. I used earlier years. For 1991, 5700 - 6000RPM is desired WOT. You will be lugging that motor by using a 19" pitch. Might need to go with a 15" to get the RPM's up there. Wait until you get motor and test it yourself. If it then runs less than 5500RPM, you should re-prop. I think the general rule is 2" smaller pitch change equals 400 RPM WOT increase?.?
Here is a good read on some prop tests:
http://continuouswave.com/whaler/ref...rWDSingle.html