I've worked with some big 4 cylinder engines in farm tractors, both gasoline and Diesel models, and most of them have a balance shaft to set up an opposing harmonic to the destructive one that's been plaguing 4-bangers since T model days. There was a vibration-absorbing mount system sold for the older engines under the brand name "Float-A-Motor", but it simply masked the shake with some very squishy rubber cushions. It really did nothing to reduce the vibrations. My Dodge Ram 50 (Mitsubishi) pickup had a balance shaft, driven by something that closely resembled a piece of bicycle chain! I'll keep an eye out for that book- - - -it sounds like some interesting reading.
Jerry
