OK so ive blueprinted a 4 stroke engine and this involves weighing the conrods and getting the purfect balance accross the crank, removing all the burs etc and genrally getting all the tolerences bang on. So on a single cylinder 2 stroke what can you do and how do you do it?
fetch it round here lol no point trying to reinvent the wheel.... go with kart tuning technology thats been around for decades. smooth out flow, no angles - but no polished surfaces as it actually fks up flow..... the air moves faster over a mirror polished surface and it separates from the fuel, fking up the atomisation of the mix. good compression but not so high as it causes detonation and fks up low down torque... assuming its for a ped.... as discussed, youre better off going for an enduro bike tune, with a wide spread of power, rather than a peaky narrow power band of a geared road racer, due to the way the cvt works. ideal port durations for this are 190 exhaust and 130 transfer.... boost port about 2mm below the transfer, bmep 8.0 - 9.0 bar. is all tried and tested this daz.... isnt hard to do but especially with the porting, once you've took metal off you cant put it back on, so its better if you get the engine on the bench, print off that degree wheel and do some measuring before you go mad filing loads off the exhaust port lol. it may be the cyl just needs jacking up & decking & no need to raise the ports.... another easy way is to compare the port mapping (basically a tracing of the port's size and positions in the cylinder) to other cylinders of similar capacity with known power output and delivery curve. as i said u dont want a bonkers power band on a auto ped otherwise it just wont work. fetch the engine round here lol.
Do you mean in terms of balancing the crank halfs together? Assuming you've put a big end in it. We used to press the crank together then turn it on v blocks and check the tolerances on the crank with a dial gauge. Effectively to get the crank halfs in sync with eachother to balance them.
You need to do this before you worry about port heights etc. http://m.youtube.com/index?desktop_uri=%2F&gl=US#/watch?v=2owMCsKAcco And agree with everything vvtr says. Espesh the smoothing of ports. People seem to think polishing everything is good, inlet needs a rougher finish. Can polish the exhaust though, if you take any material out of the exhaust port take it from the top not the bottom of the port. Also light cross hatching helps the rings and piston bed in on the bore. Getting the crank balance right makes a big difference though.
Works for me but I'm on iPhone, try this.. www.youtube.com/index?desktop_uri=%2F&gl=US#/watch?v=2owMCsKAcco
