RE: Engine ID help requested (was told Quadra 75 is a Sachs Dolmar 4.2)
I have a Taurus 69. I have never cranked it, but I am finishing a plane for it now. It's cylinder looks a lot like the one in the photograph. Of course its got a different crankcase and is EI. I hope it runs ok. I'm pretty sure these engines have Sachs cyl/pistons, rods and cranks.
I dont think I saw any impressions of how the stated engine ran, other than the 24 X 12 prop. What about vibration? With the double web crank and extra bearing I bet that engine would run forever. Good luck with it.