Below is a copy of some text I put onto another thread in late December 2016 on the subject of excessive oil consumption.
I had taken my Comet head off had new valve guides with a seal put in by Conway and then treated the casting with Loctite 290 (could not find any 294),
Below is the result so far.
Now replaced the head after pressurising it (off the bike) via a modified push rod tube. It was difficult to really check for bubbles when I put water into the inlet port because of the angles involved, but I could not see any.
However I cleaned off the inlet port and rocker area above the inlet valve, heated the head to above boiling (no signs of oil from cracks or porosity) and painted the Loctite on as it cooled according to Loctite instructions.
Also ground a channel about 1/16 " deep and 3/16 wide down from top of the inlet valve guide to the rocker tunnel in case oil was settling round the valve guide. ( though I doubt if this was the cause of my consumption.
Deglazed the bore with emery cloth and after much cleaning put the piston back in without moving the rings much to minimise running in.
Then on the advice of a Mechanical Engineering friend, I did not oil the bore except for a little oil in the ring grooves. On the first runs I ran the engine hard under load so as to force the rings out onto the cylinder and avoid glazing.
Because of a bad cold and nasty weather I have only done 150 miles so far and friends say there is no blue smoke and after a check I do not seem to have used any oil at all and would normally have expected to use at least half a pint in that distance.
As a research Engineer who always had to identify the real cause of any problem so that it did not come up in production or later I have not obeyed the rules by doing several things at once.
However I am much too old now to keep pulling the bike apart just to prove a point, so have done a belt braces and elastic waistband job on the bike and hopefully fixed a very long standing irritation which coked up the head and caused lots of pinking and loss of power up hills.
Matty,
A moment ago
e subject.