[TR] compression test on non running engine?

[Randall]

> can a person get a fairly accurate compression test on an engine thats on
> an
> engine stand by turning by hand?

It would be difficult, since it takes a LOT of force to turn the engine
against the compression even of one cylinder.  Almost certainly you would
wind up turning slower against the good cylinders (allowing them to leak
more and hence read lower) than any bad cylinders.

OTOH, you could always hook up the starter and a battery to spin it.

There's also the question of why you would want to do that.  If you already
have the engine out and suspect it might have bad rings and/or valves, just
replace them!  If it's a freshly built engine, then lack of run-in will
likely render any variation meaningless anyway.

Randall