IC to electric conversion table

http://lmmac.net/i-c-to-electric-conversion-table/

IC to brushless ( for aircraft but its better than nothing)

https://www.cmfhobbies.com/IC-Engine-to-Electric-motor-convertion/I205.htm

Hope its some help

Hi Andy
I work on the motor case around the same size as the prop diameter, the rpm and power of the old motor.
Add a few more rpm as we like to go faster.
Matching the revs from the old motor e.g. 20,000.
Kv of the brushless motor times the Lipo Battery cell number(4S= 14.8 volts) e.g. 1450kv times 14.8= 21460 rpm.
So an OS40FSR was 1.6HP @ 20,000.
Replacement 3648-1450kv = 21460rpm(no load).
Power 750 watts = 1HP and the 3648-1450kv is 1600watts.

As for brushless to brush motors you can match the rpm, but, the brushless are far more powerful than the brush motors.

As for a conversion chart it would be a big task and some of the gear is not available in all countries.

Canabus