Aluminum to S. Steel

[Unkydave]

On my 19' Chapparal OMC 190 hp V-8 Cobra I am using a 14.25 x 17 aluminum 3 blade prop. QUESTION: Under acceleration do aluminum prop blades flex "flatter" thereby reducing pitch such as when pulling up a skier? When switching to a stainless prop [stronger blades that don't flex?], should I go down 1" in pitch? Stainless props come in even pitches and aluminum props in odd pitches so going to a 16" pitch S.S. would be a 1" reduction. I'm thinking of a 14.0 x 16" 4 blade Solas stainless. My boat weighs about 3300 lbs. with passengers and gear, plus pulling up one or two skiers. Any thoughts appreciated. Thanks, Dave.

 

[rndn]

Re: Aluminum to S. Steel

Yes, aluminum blades do flex mush more than a SS will flex. Most people do reduce by 1" the pitch to compensate as long as you are currently getting the maximum suggested rpm's at wide open throttle (WOT).

 

[steelespike]

Re: Aluminum to S. Steel

Not an expert::
It would depend on what your present rpm and speed are.
I've read where stainless raised rpm and speed and lowered rpm and raised speed.A stainless can lift, improving speed ,there is usually less slip which can load the motor more but also improve speed,it can combat ventilation improving setup and thus speed.If I was going stainless I wopuld try to find someone that will exchange props so I can select the best one for my application.Today I would start with the same pitch.
The experts may be along to explain the technical improvements of stainless props.