Curious & Confused on drive ratio...

[Bubba1235]

Looking at something I can't really find a reason for, maybe someone can share the answer.

Mercruiser (MC-1) behind a Chevy in-line six has a gear ratio of 1.65 to 1. The same drive behind a Merc 470 has a ratio of 1.89 to 1.

Both engines produce almost identical torgue, HP and have the same WOT RPM ratings. So why two different gear ratios?

 

[mkast]

Re: Curious & Confused on drive ratio...

Without having the specifications in front of me, I'm guessing the straight six develops more torque, at a lower RPM than the four cylinder.

 

[Don S]

Re: Curious & Confused on drive ratio...

Both engines produce almost identical torgue, HP and have the same WOT RPM ratings. So why two different gear ratios?

And how do you know this information? It has never been published. My guess is that it's not the same. I did notice the 488 (has a quadrajet carb) uses a 1:65 ratio.