Posted by ken on October 22, 2002 at 19:45:09:
In Reply to: Gear Ratio posted by Haji on September 20, 2002 at 05:05:09:
: Hope someone here will help me, to calculate the proper Gear Ratio for Marine Transmission. The Inboard Transmission ratio available 2.07,2.58,2.91 and 3.53:1
: Inboard engine published rated output 180 Hp (132 kW) at 2100 Rpm and Max 220 Hp at 2170 Rpm.
: Propeller diameter 28" , propshaft 2" dia and propshaft length (nominal) 10.5'. From the "ingredients" given which gear ratio to applied for the best result. Thank you,
I ran the numbers for the info you gave and I got 3:1 gear/34x27 three blade prop.
I ran 3.5:1 gear and got 36x31 prop.
2 inch shaft showed OK.
It said max speed 11 knots with the info you gave.