[stpltn250r]

Im trying to get some info on these things and how each one affects a motor. Alot of timing can affect the head and pipe temps changing the effective rpm range. Compression and timing can effect rpm range. Rod to stroke ratio and timing can effect rpm range.

Maybe someone can point me in a certain place to find some good useful info. I have looked over two two stroke tuning books (Jenning and Bell) and got some info but just looking for some from guys that build motors.

[acecarlos]

Hard questions to answer without being more specific to engine build and application. You can generalize and say more timing = higher RPM's and a peaker Power Curve as far as ports go.

More IGN timing affects Torque at lower RPM's as well as higher Power Output at the higher RPM range.

Both Port & IGN timing changes should be tied and be part of the Pipe, Fuel, Dome, Compression and squish design/velocity parameters. Keeping harmony in all these variables will dictate how much of each you can increase or decrease.

Carlos.

[30mil]

i thought increasing timing moves the power down as well as rpms

engines seem to rev out higher with less timing to me......(if compression is not to high) around 145-160psi