Variations in cylinders to be ported

[fordnut79@hotma]

I don't know if I can explain this as well as I hope , but here goes. I was reading graham bells 2 stroke book last night about blueprinting; mainly about how much one engine varies with another in manufacturing, and how much they can be off tolerance. Also today I was reading about atc/trx deck heights and they can be off by as much as .070" one site said. I know professional porting individuals can port match and get rid of casting flaws and such,but how can they port a cylinder accurately and get the right degree of duration without your crankcase bolted to it and with a degree wheel. Not to mention the differences in the different year heads(3 types I'm told). Is it just a professional educated guess? I thought a 2 stroke was a finely tuned instrument relying on all parts functioning as a whole. Or maybe I'm splitting hairs and over analizing. Or does deck height only contribute to squish and compression.

[TecateDan]

the guys who do it right want the whole rotatin assembly to set it all up right. Deck height is mostly for squish and compression which can be measured and which a lot of people will ask for.