TRANSMISSION GEAR RATIO

harry

Well-Known Member
Mar 1, 2005
269
0
Miami, FL
Repowering my Shamrock 246 open. Going FROM a 2001 Mercruiser Horizon MPI with a Borg Warner 1:5-1 trany TO a 2021 383 Stroker with a Hurth 2.0-1 ratio already in place. Any drawbacks on the 2.0 -1 ratio? The stroker has more torque so I may possibly need to increase prop size. Would the Hurth 2.0-1 ratio have any issues that I should be aware of? I really don't want the Borg Warner 1.5-1 on the new 383 Stroker if I don't have to. Any real significance from a 1:5-1 vs 2:0-1 ?
 
Last edited:

Mistress

Moderator
Staff member
Supporting Captain
Jan 22, 2005
7,475
237
San Jose, CA
What do the calcs say would be the proper prop? Can you fit it and how far out of square will it be?

My simple math say you''ll need 30% more prop for the gear alone.

If you can go 30% more pitch and an inch or 2 in diameter, you might be OK.
 


Latest posts

Top