Oil consumption

[laxy]

1955 16MS just returned from a very enjoyable 100 mile run after rebore and new piston rings, valve guides and valves. My barrel has been rebored to suit my second hand but very good condition +20 heplex piston with 4thou clearance. I've fitted +20 piston rings from Cox and Turner and was a little surprised to find the ring gap was 20 thou when placed in the barrel. I wasn't too concerned as the max gap is 30 thou and minimum 6 thou. So they are within tolerance. Before setting off this morning I topped up with oil. I'm still on SAE 50 until the weather gets a bit colder. When I got home I checked the oil tank and found it needed half a pint of oil to top it up again. I just wondered if this was excessive for 100 miles of very careful running in riding.

[clive]

pint for 200 miles seems a bit excessive but after a rebore the barrel/rings won't have settled in together which is the point of the running in. I would not worry, especially if you had drained the crankcase during the work as refilling this until the return started working would account for quite a bit.

[laxy]

Thanks for your comments Clive. I will continue to put more miles on the clock to run the rings a nd barrel in and keep my eye on the oil consumption to see if it improves.