memories--
there are sounds which associate with certain marques.
I could always tell by sound --a Buick transmission (3speed )
A Ford V8 starter motor
A Chev V8 dual exhaust .,
A Buick Dual exhaust
etc..
Once knew a guy who worked on Chrysler starter motors -trying to quiet the very distinctive sound of the gear/flywheel engagement -
I could pick out that sound a block away.
Model engines are more difficult -being two strokers -the size determines primary difference (operating rpm)
Basically -after futzing around - I found that stiff props -with pitch high enough to prevent tip rip-- plus LARGE expansion mufflers were the most practical fixes.