I have a Rover 3.5 which has had new bearings and rings, it runs really well std spec with a modified manifold to take a Dgas 38 webber.
On cold start it is fine no visible smoke, when at temp according to a mate following it shows a small amount of oil smoke at gear change.
But when hot starting it throws out a large cloud also when pulling away there is some. it is using about 1/5L for 300 miles. Left side is the worst.
Compression is just over 10 bar on all cylinders and the plugs are clear. The crank case breathing is just to the air filter.
My thinking is valve stem seals ( which have been replaced) or guides. Could adding pcv valve to the system help?
Any thoughts or suggestions before I take the head off.