stainless v.s. aluminum (same prop size)

[quebec#1]

Whats the difference for lets say a 13x19 aluminum prop vs a sst prop of the same size ? Comparing the aluminum 13x19 vs a sst would it be like a 21 aluminum pitch ? Highher rpm"s ?

 

[steelespike]

Re: stainless v.s. aluminum (same prop size)

Speaking very basically the ss prop will have a better grip it may actually lower rpm when replaced in the same demension. Depending on where your at you would lower the pitch with the ss.The ss will resist ventilation as well.The ss is also a little harder on the drive train especially if you run into something.

 

[180shabah]

Re: stainless v.s. aluminum (same prop size)

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[wire2]

Re: stainless v.s. aluminum (same prop size)

Speaking very basically the ss prop will have a better grip it may actually lower rpm when replaced in the same demension. Depending on where your at you would lower the pitch with the ss.The ss will resist ventilation as well.The ss is also a little harder on the drive train especially if you run into something.

I believe a similar ss prop will yield more rpm than aluminum. The blades are considerably thinner so will see less friction in the water. More rpm will mean more speed.

 

[steelespike]

Re: stainless v.s. aluminum (same prop size)

I believe a similar ss prop will yield more rpm than aluminum. The blades are considerably thinner so will see less friction in the water. More rpm will mean more speed.

The stainless is more efficient, loads the motor more.It has a finer edge and stronger blades and usually a more sofisticated design.It operates closer to its theoretical performance capabilities than an aluminum.It will generally lower rpm when replaced in the same demension.But it may still increase speed depending on the present rpm.Generally it is recomended to drop in pitch when going to stainless.Again depending on the present rpm.

 

[MikDee]

Re: stainless v.s. aluminum (same prop size)

The stainless is more efficient, loads the motor more.It has a finer edge and stronger blades and usually a more sofisticated design.It operates closer to its theoretical performance capabilities than an aluminum.It will generally lower rpm when replaced in the same demension.But it may still increase speed depending on the present rpm.Generally it is recomended to drop in pitch when going to stainless.Again depending on the present rpm.

I agree, the stainless doesn't flex, plus it is much heavier so it works the motor harder, but also due to this it is more efficient, so for the every rpm it turns, it moves the boat a further distance along then the aluminum. Usually this results in a drop in rpm (average 200rpm) if you kept the same pitch, hence the reason to decrease to the next lowest pitch, then the result is usually an increase in speed. This also varies by design of each prop, diameter, & blade size. I've also found sometimes the blade size on a Stainless prop is larger then an aluminum.

 

[BAYLINER185]

Re: stainless v.s. aluminum (same prop size)

MIKEDEE is right on the money

I switched out to a SS prop on my bayliner 185. Exact same pitch the Stainles sis a little bit bigger diameter.

I am about 200 RPM less then previous and Im about 2 to 3 1/2 MPH faster.

 

[Frank Acampora]

Re: stainless v.s. aluminum (same prop size)

You fellows are comparing apples to oranges.

I have several stock Chrysler props manufactured by Michigan. The exact same prop 13 X19, no cup, in stainless runs 400 RPM and 2 MPH faster on the same engine/hull than the 13 X19, no cup, aluminum. Apples to apples.

 

[quebec#1]

Re: stainless v.s. aluminum (same prop size)

Thanks Guys i think i will look for a 21 sst maybe a balistic prop.

 

[QC]

Re: stainless v.s. aluminum (same prop size)

The flex difference also usually favors Aluminum for hole shot. Also, when compared to the hydrodynamics, the weight difference of a Stainless is inconsequential.

 

[John_S]

Re: stainless v.s. aluminum (same prop size)

"Thanks Guys i think i will look for a 21 sst maybe a balistic prop."

So, you are 2-300rpms above your top-end of your wot spec?