prop performance

[tautog_33]

Hi guys just wanted to share some prop numbers had my prop balanced and dropped the pitch to 16P.

The motor is a 1988 135 Mercury 2.0L mounted one inch above the keel.

Original prop numbers with 14.5 X 17P

3400 rpm 18 Kts
4000 rpm 23 kts
5200 rpm 35.5 kts WOT

New numbers with 14.5 X 16P

3400 rpm 20.2 kts
4000 rpm 25.4 kts
5600 rpm 33.9 kts WOT

I gained 2.5 kts on the cruise and lost 1.5 top end. The motor sounds alot better at cruising speed and seems to run best at 3800-4000. The next thing on the list is tabs and fuel monitor.

[eggsuckindog]

You did good, cruise is where you are most

[tautog_33]

Originally Posted by eggsuckindog

You did good, cruise is where you are most

Thanks ESD!! Do you think I would of got the same results by raising my motor one hole?

[eggsuckindog]

Look I am as amazed as anybody what a difference it made, I thought I was pretty good before - slip was 14% under 4K and 11% above which are damn good numbers. It went 11% under and 7% to WOT which are unbelieveable - I think I used the correct LU ratio 1.87.

I just re- read your post, you got alot out of 1" pitch 400 RPM - who knows you may have gotton 200, I would have done mine before if I knew - just sharing what I learn, nobody was born knowing this stuff.

[tautog_33]

Thanks for the reply ESD I thought the same thing about the extra 400 rpm. I was expecting 200 and was going to raise engine to get some more out of it.