What performance can be expected from this prop change?

[Jgcrock99]

Good afternoon,
Being honest, I'm just trying to do a cheap prop change and had a question. I have a 4.3 mercruiser lx in a 95 Chaparral 1930 sst. The prop on the boat when I bought it is a 14.25x21p black max aluminum. Ran well but has reached the end of its life. I'm currently running a 23p but it's only good for about 3 people kn the boat. I want a stainless but have a hard time spending 400+ on a new prop for a 30yo boat. Found a stainless on ebay that is a 13.5x22p and looks to be in good condition. I know there are many factors that impact performance when changing props like 200 revs per inch of pitch approximately, stainless vs aluminum with flex, etc. Curious what I could expect from a change from 14.25x21p aluminum to a 13.5x22p ss. I can hit slightly above wot with the 21p, about 4900-5000. Thank you.

 

[jimmbo]

Being that the Props are not likely the same Brand or Model, and different Diameter, not to mention Rake and/or Cupping, it is not an Apples to Apples Equation. A 3/4" change in Diameter, leads me to think that 22 is not a Prop for the Mercrusier

 

[Jgcrock99]

Being that the Props are not likely the same Brand or Model, and different Diameter, not to mention Rake and/or Cupping, it is not an Apples to Apples Equation. A 3/4" change in Diameter, leads me to think that 22 is not a Prop for the Mercrusier

Thank you. Ended up just getting a new turning point 14.25x21p that was on sale. I've been satisfied running aluminum so far with my setup I'll just let it ride. I want stainless but for what I do it's not really necessary. I also take the boat to different lakes I'm not familiar with from time to time so may as well save my lower unit should something happen

 

[cyclops222]

Lower unit destruction tests have POSITIVELY proved that a hard hit with either metal DESTROYS the lower units. Tests were done WAY BACK in time by Kiekaufer / Mercury company. On a concrete wall below the surface. At normal cruising speeds.

 

[cyclops222]

SOOOOO
Buy and use ANY prop that you feel would do MORE of what you want from it. Speed Power out of a dead stop. Mileage.
Enjoy
Do call the prop company to find out the EFFICIENCY of the prop before buying.

 

[Chris1956]

I ran a sterndrive boat on a shallow bay. When accelerating the prop would often drag thru the silt and mud. It would rip up an alum prop on every trip, but had no effect on a SS prop. I got many seasons out of the SS prop, w/o damage.

if you do not have this issue, an alum prop works just fine, especially Turning Point Hustler props, at least in my opinion.

One more thing. The bay I boat on has no rocks or hard stuff at all. Rocks or hard stuff + SS props can often lead to gearcase damage.