Username666

Hello everyone,
I am new here and this is my first post. Sorry if I have posted in the wrong place.
Anyway, is there any relationship between crank size and ignition timing? I mean if I increase crank size will it effects ignition timing?
Regards.

Matt Cramer

Increasing the stroke while leaving everything else equal (assuming you have also changed the pistons and / or rods to keep the compression ratio the same) typically results in more cylinder filling at low RPM (requiring less timing there) and worse cylinder filling at high RPM (in which case you often make more power with a little more timing). In the end, there's nothing that works quite as well as dyno tuning for getting the timing on a new build dialed in.