engine oil loss

[Thackers]

Hi, I've noticed since changing my cyl kit that I'm losing engine oil at a rate of around 50ml in 150 miles. There is no white lingering smoke like you get with a shot drive side oil seal, it is a bit more smokey on start up with the choke but this clears up. Have any of you knowledgeable chaps any ideas? It usually doesn't use much oil and i don't think changing the kit is the reason though this has prompted the extra scrutiny. The side gasket is new and there's no oil patch on the garage floor, also the rear hub seal is new.
Thanks

[Fast n Furious]

A blocked chaincase breather would do it, but this is really an unlikely secenario.
Fit a party balloon over the breather and warm the engine up. The balloon then acts as a visible expansion vessel.
When the chaincase warms up, the atmosphere inside should expand and inflate the ballon to some degree. If the balloon pulses with every stroke, then the drive side crank oil seal or Halite washer is the likely culprit.

[Thackers]

Thanks for the reply, I'll give the balloon test a go