Well , this is for the engine
knowledgeable. I've been tooling around with a flat 4 ( well known brand) engine for education reasons ; replaced exhaust valves ( hand lapped) into recut seats.
Compression "seems" much improved , on pull thru ( not leak down tested ,at this stage).
Here's the query, pulling through on the exhaust stroke the exhaust is sucking in prior to the actual exhaust ........as if the exhaust valve opens maybe 10 -15 degrees before the piston hits BDC. Is this typical or "normal" or is the timing of the cam misaligned??
The case has not been split as only the top end has been worked on.