prop question

[spareparts]

I've been over this time and time again, pitch and diameter are a starting point, blade composition is not that important till you get above 60 mph. Design and profile are the most important thing about props. I can take 10 different 19 pitch props and all ten will perform differently. Blade surface, rake, number of blades, blade design, ventilation holes, over hub or thru hub, cup, tip roll, etc.......They all make a difference. In lower speed props, generally the aluminum wheels are more of a generic design and perform good all around, lower end stainless props duplicate the performance of their aluminum counterparts. Every put a stainless prop on a Volvo single prop out-drive? It will run slower than the aluminum one. When you get into higher end props, they generally have more specific design goals(higher prices too).Don't always go just on the pitch either, there are several prop manufactures that rate their pitch differently. Mach was real bad about this(they are out of business now), their 20 pitch four blade checked out at 24 pitch on the blocks. I've had some props that none of the blades were even close to the same pitch(Eagle and Turbo). I've sent props to have them lab finished(by Merc racing) and the boat slowed down afterwards. Point being, they are very loose guidelines, until you bolt it on the shaft, you will not know for sure. Aussie, from my experience with the 3.7, you'll be hard pressed to find a better wheel for what you are doing than a Mercury Mirage plus. you need to base line the engine with a known unaltered prop to get a feel for where you need to be, but from there own, its trial and error. BTW, its hard to beat mercury props.

[Destroyer]

Originally Posted by aussie

Would it right to say a stainless prop of 17 inch pitch would be the same as a 18 inch Aluminum prop ---my understanding is 2 props same pitch one steel the other aluminum the steel will give you better holeshot and more speed at wot correct ???????

I did answer your question in my first reply Aussie.

Originally Posted by Destroyer

So yes, to answer your question, it probably would be right to say a stainless prop of 17 inch pitch would be about the same as a 18-19 inch Aluminum, all other factors being the same.

And read what SpareParts just said about props. His reply is basically a longer and more detailed version of what i said when I said:

Originally Posted by Destroyer

The fact is that props are so infinately variable that it's almost useless to say "this is what you have to do" vs "that is what you have to do". The ONLY way to know what prop is right for your boat is to actually know what you want your boat to do, and then try several different props until you get the one that's dialed in for your needs.

[aussie]

The best way of learning more is to read and listen but not speak that's why I am asking a lot of questions