Re: New rebuilt engine-burning oil after 700 miles
It seems to me that these engines were designed to consume a bit of oil. That being said, I think you are right that 1/2 liter over 700 miles is somewhat excessive and it should not puff visible smoke on start up.
When the engine was rebuilt do you know if the valve guides were replaced or were they simply knurled to remove the play in the valves?
If the guides were knurled, I would say that that is the cause of the oil consumption.
I recently spoke to an engine rebuilder with over 40 years of experience working on British engines and he informed me that it is not acceptable at any time to knurl the valve guides. Since our engines do not have valve stem seals the valve and guide must fit tight according to the factory specifications. When a guide is knurled it opens the top up like a funnel, which allows more oil to collect at the valve stem and this oil then runs into the combustion chamber and is burned. If you are using an auxiliary upper cylinder oil feed line, remove it. This too leads to more oil usage if the valve guides are suspect.