weee, everyones 5 c worth!
how you mounting em in the lathe? plain old 3 jaw in the bore and then...how to ensure its dead square?
expanding arbor would be ideal... any consideration of spigotting out the top so you dont need a head gasket?
then the port timing itself... have you started mapping them? worked out the time areas? done a template?
opened up the intake and transfer to allow extra flow? this is all before even considering tampering with the durations.
im with that theory of hacking out the transfer walls... they serve no purpose and make getting into the port itself a breeze.
allowing for manipulation of flow.
can always bog em up a bit with poxy or welding...
then there gets this really tricky bit.
i figured you could pull it off with spark flash photography, otherwise...
you want a perspex head, with the same combustion chamber shape as the head you run.
a source of fog or smoke on the intake...
a vacuum on the exhaust...
and to get a true dynamic idea of gas flows...
a high speed camera so you can spin the engine at near operating speed.
yep, a flow bench but rather than static, which means nothing...its dynamic. useful.
(at least thats what i think, though i never bothered actually doing it...)
its not just about "port timing"... its about flow...turbulence... and how else can you see that at 5.5k it suddenly stalls at the transfer? anyway...
then theres that whole subject of the intake, tuning that side of the engine...
and in the end...using el cheapo engines made from recycled beer cans...
the realisation that the hours of work involved, the nikhedonistic drive to get it done, was all in vain, and one should have gotten a morini/denardis in the first place.
hate to say it, but you will spend a LOT of money destroying parts before you get it "right".
hmmm...say you eat five cylinders...thats $200 at the price i find em at.
five pistons... another $100... youll always have one drop its keeper pin and destroy everything.
two engines... 400....
bearings, parts, time, labour... countless...
morini 50cc as used in a ktm50... about 5-600 last time i looked... virtually bulletproof.
i know it takes out the satisfaction of DIY but all ive found with these engines...is NO SATISFACTION!
PS...when you make a decent pipe, even for a stock standard engine, which you will end up doing because anything else is so much effort after the first three blow up, the gains are extraordinary