Originally Posted by Norman
…..and position, where intake tunnels is connect to transfer ports, must be at the point where average positive pressure in trans ports is the lowest. Maybe intake tunnels, from main reed, must be placed in the “half moon”- between cylinder wall and transfer port inner radius wall, where Jan added cooling.
With RGV engine closed bottom crank space (without side reeds, add photo), testing was done with another type, its like intake tunnels added at the lower, say starting point of transfer port. From 8000 rpm engine stopped and only first gear overcome 8000-10000 rpm dip. Only two16 mm holes on separator sides that depress crankcase, eliminate dip.
Haufen, Frits I fully agree too. But at the moment I am fully illegal on the road. No technical inspection, no insurance, so I feel like a bunny on the road. One eye always ready to recognize police car. But now, as my moto gp commentator job postponed, I have more time finally to travel just 250 km to put all the stuff on my friend's dyno.
Other interesting thing. Accidentally, with spark plug 0.9 mm gap, found how piston/head clearance changed on this particular engine.
Very low rpm, piston just touching ground electrode – gap 0.8 mm
Not warmed engine, shortly to 14000 rpm – gap 0.5 mm
Then full load on the road – gap 0.2 mm (with usually unstable work from low to mid range with such small gap)
So difference is 0.6 mm from piston center, maybe piston squash area approached a similar distance. Maybe this explains why this engine spins freely with no less than 0.9 mm squash height or 0.3 mm that left with heat and revs.
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