What is a reasonable psi for compression test on a US-spec, 1984 XJ6?
Depends on the CR but I would be looking for <> 130psi and up.
As Robin says, Stuart, but evenness between cylinder is also important - so the procedure and condition must be the same for each cylinder test. The absolute pressure, together with compression ratio, tells something about engine wear…
Frank
xj6 85 Sov Europe (UK/NZ)