[haasad]

Re-timed at 5.0mm lift.

Problem is now worse I still have acceptable inlet valve clearance at a minimum known 2.0mm and now its blocked a 1.25mm on the exhaust about 10 degrees before TDC. I took the trouble to check clearance across both inlet and exhaust valves through 2 crank revolutions and it happens in the same place each time. Back out the adjuster and she turns perfectly.

Should I try re-timing again at 5.4 mm on the basis I have nothing to loose.

There has been no dimensional change in building this motor ie the case was not faced or the cylinder lands machined the heads have not been refaced,the valve seats were re cut which will give extra clearance it anything.

The heads are a matched set as are the cylinders.

The pistons are 92 mm diameter 10.5:1 JE's and the cams standard S.

Rather than machine the pistons I would rather swap to a "softer" cam ?

Andy advice appreciated.