Do I need to change prop pitch?

[Fish'n Lewi]

1) Nothing really.
2) Quicksilver 2038P19 Aluminum
3) 13x19
4) 5400-5500 @ 40 mph gps
5) Mercury Four Stroke (75ELPT 4S), 2005, 75, 1F75412DD (model #)
6) Tracker Pro Guide V16, 2006, 16' 1,194lbs

What I want to know is if I change from the aluminum prop to a stainless which way do I go if any with the pitch. I am getting very different answers from "keep it the same" to "you will want to drop 2" as your aluminum prop is flexing 1-2". I want to keep my current speed or go up without going over rpm's obviously. Engine says Max WOT 5500, manual says 5000-6000.


Thanks all!

Lewi

 

[steelespike]

Re: Do I need to change prop pitch?

Your present numbers indicate about 6% slip an excellent number. 40 seems very good as well.
Your mid range on rpm so room for changes either way.
If doing a entry level prop I would start with the same pitch.
When changing material results can be somewhat unpredictable.
At about 3 times the cost I wonder how much improvement a ss could manage over your present numbers.
The Turning Point Hustler Is an aluminum prop said to deliver close to ss performance.

 

[jestor68]

Re: Do I need to change prop pitch?

If you put the same pitch SS prop on there and don't change your set up, expect to drop 100-200 rpm.

You can stick with the same 19 pitch if you raise the engine one hole, as that will gain back what would have been lost rpm and give a boost in performance.

The hot ticket would be Mercury's Laser II.

Since your motor's rated hp is at 5500 rpm, you want to maintain at least 5500 rpm at WOT.