17 replies to this topic

[Cooperman]

On the subject of pistons hitting valves, they only time I have heard of this was with a 1071 Cooper 'S' which had a 649 cam, 1,5 rockers and over 11:1 CR. With a 1071 the chamber volumes would be small and this the distance from piston top tos valve heads would be small. It would be even less with a 970.

 

Whilst competing the driver missed a gear on change up and the engine revved to 'a high figure' (maybe 8500+) and one of the valves stayed open due to the valve bounce 'kissed' a piston. The piston was fine and the valve was changed.

 

A road Mini is unlikely to fact this issue.

[JimmyStinkpickle]

Refit the cylinder head after a trip to the machinist and completed the 20 minute cam break-in. Valve clearances now ok. Just got back from a 30 mile drive and she runs beautifully. Thank you all for your advice!

[JimmyStinkpickle]

Just for completeness and to throw in another cause, using old fuel will cause the fuel to turn to varnish on the valve stems causing valves to stick.

 

This was my thinking as well. There was a little bit of old fuel left in the tank when I ran the pump for the first time. I squirted a little ATF on the valve stems for good measure. In any case, all is well now. Thanks!