Vibration Damper / Harmonic Balancer?

[digger]

How can you tell the difference between an "Eta" and an "i" harmonic balancer/vibration dampener?

I belive there are there various types for an M20B25 (later and earlier versions)? How can you physically tell the ones for the M20B25 apart? What are the differences between the "i" ones and whats the reason for the change?

In case you are wondering i am rebuilding an M20B25 engine and want to know which is the correct one to get.

Cheers

[Adrian_Visser]

the later m20's have a toothed ring for the crank position sensor on the harmonic balancer (at the front of the engine) whereas the early ones have the crank pos sensor at the back. not sure if theyre different other than that.