Has anybody here built the Atkinson Differential engine by Vincent R. Gingery and actually got it to run? I built one and it turned out very well. I went through the run in procedure by hooking it up to an electric motor and running it for hours. It seems like it is firing OK but not strong enough to actually run. Lots of talk about this online and the consensus of opinion is that there usually isn't enough compression to get it to fire strong enough to run. I went to a lot of trouble to be sure to get the ignition timing just right. Even hooked up an auto timing light to make sure. I got it out again yesterday to do some more investigating. Rolling it over by hand it seems to develop more compression if you roll it over in the opposite direction to the way it was designed. I have been thinking of trying it that way. All I would have to do is readjust the position of the ignition cam to change the firing position. Any thoughts on this ? I can't really think of why it would develop more compression turning that way.