Dyno changed lifted cylinder
Today I tested the changed Y-2 cylinder.
Have to say I'm pleased with the results, I have defeated the Y-1 cylinder witch was until now my best cylinder.
I gained with widening the exhaust port and Chamfering the ports a sollid 1HP
Here you have four runs nicely to each other
26,3 till 26,5HP
![](images/4-runs.jpg)
Her one off the average runs with 26,4HP
![](images/run-y-2-26,4PS.jpg)
Her the difference between the lifted Y-2 cylinder and the Changed Y-2 cylinder
![](images/Y-2-vs-Y-2-rounded-ports.jpg)
Here you see the steps
Orange run - stock base gasket Y-2 cylinder
Green run - lifted Y-2 cylinder (0,9mm higher)
Yellow run - lifted and changed Y-2 cylinder
![](images/drie-run-zelfde-y-2.jpg)
The question remains.
What did what?
Widening the exhaust port with 0,8mm should normally gain power where already power is, but here it is revving higher.
Rounding the ports gives a better explanation, because you change the timing a bid.
Will investigate this further