ESE's works engine tuner

[TZ350]

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170/88 ... Red Line on graph.

I recall someone talking about dyno testing a rotary valve two stroke. Where the valve seized in the fully open position at WOT and max RPM. With the sympathetic inlet resonance it apparently still made the same power but it did not pick up again once the throttle was closed. Probably explains how maximum powerwise I got away with crazy ass timing. Looks like more subdued timing is required if I want to ride the thing.

[husaberg]

.
170/88 ... Red Line on graph.

I recall someone talking about dyno testing a rotary valve two stroke. Where the valve seized in the fully open position at WOT and max RPM. With the sympathetic inlet resonance it apparently still made the same power but it did not pick up again once the throttle was closed. Probably explains how maximum powerwise I got away with crazy ass timing. Looks like more subdued timing is required if I want to ride the thing.

Pretty sure Frits or Jan wrote something similar to that about one doing that in practice or a race. ran good but refused to start again
Pretty sure piston ports get harder to start as the inlet duration gets extreme as well.

What would change if Rob contoured the leading edge and trailing of the disc to the same shape as the round ish port.
not meaning duration more so time area and intake pulse?

TBH I thought that port would be squarer.

[wobbly]

The RSW is a slightly oval inlet port horizontally, the RSA is slightly oval vertically on the disc axis.
The RSA is better in that the narrower the port for the same timings, the less time the disc covers the port shape.
Having rounded disc leading or trailing edges , with the same timings, does NOT make more power.
That was the first test I did at Zip when the 256 engine was introduced.
Having a slightly triangular port with straighter angled sides, is better than a round port, but always has bad wear issues, the RSA vertical oval is easily the best.
All dyno proven reality.