DaveMarles
Well-Known Member
- Joined
- Nov 5, 2003
- Messages
- 438
Ian, There is no way you can compare engines in the way that you say. For example the induction port on the A90 is relatively small and with the same timings the time area is much less than the K90. The short stroke of the A90 means that it will have better torque in the lower rpm range too. Short stroke on a small two stroke engine does not mean high power at high rpm. This is the opposite to 4 strokes.
For example: If you take a Picco 90 (close to 1:1 bore stroke ratio)and make all the port timings exactly the same as a CMB 90 ( short stroke) then the P 90 will want to rev but have less low end power.
Also. If you use higher transfer timings ( lower blowdown ) on the A90 it will be less peaky than the K90.
Dave
For example: If you take a Picco 90 (close to 1:1 bore stroke ratio)and make all the port timings exactly the same as a CMB 90 ( short stroke) then the P 90 will want to rev but have less low end power.
Also. If you use higher transfer timings ( lower blowdown ) on the A90 it will be less peaky than the K90.
Dave
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