Leaderboard

In my experience the throttle doesn't make much difference, but you really want all the spark plugs out so the engine spins as fast as possible. You want a good battery too, any slow down of the starter will drastically reduce your readings.

Did you comp test it properly, ie all plugs out and wide open throttle?

Presumably you are confident on your camshaft timing? Perhaps some oil down each spark plug hole and a re-test will ensure its actually rings?

Well thats a bummer! You sure the values are real? Although not entirely perfect they are within the ball park of being close together. have you used your compression gauge on other engines with success? how long has the engine being sitting? my old 4age that i bought from little red spirit had been sitting for years and years. Terrible compression results at first, but they came good after some running, and gave me like 5 years of service. Great looking car by the way, will be worth the tribulations. I have managed to avoid doing rings or bearings in all my engines, I am actually looking forward to it if i ever need to. I might even rebuild a spare BMW engine just for fun, and prove i can do it, before i actually NEED to do it:P