[Pete]

Originally Posted by Terry Burtz, Calif

Pete,

Thanks for your comments.

With an iron or steel crankshaft, it is impossible to get enough counterweight to counteract the bending forces that occur at TDC when the connecting rod stops the piston, however for those that want more counterweight for events like land speed records, there is plenty of room to add tungsten or depleted uranium.

> Your engines will never be used for land speed racing unless they change the rules but since you mentioned heavy metal, it is not necessary to achieve a balance that works very well on racing engines even with a 3 main crank.. This is done by bob weight percentage and can achieve a .01 inch ounce balance over the rpm range the engine operates in.

The problem with a heavy crankshaft is that it makes an engine sluggish with the added inertia and acceleration/deceleration becomes an issue.

Balance weights are separate from the crankshaft and do nothing to reduce stresses in the crankshaft.

> I assume you meant "shafts", not "weights"? Anyway, only partially right. ANYTHING that reduces vibration in an engine will reduce stress in the crankshaft.

Balance shafts reduce the inherent shaking that comes with a 4-cylinder engine. In the case of heavy equipment, balance shafts keep the machine from shaking itself apart and fretting damage.

> Machine vibration and base mounting vibration in stationary engines is a SECONDARY problem. A THIRD order problem is vibraton to the earth itself. While seemingly not a problem, it CAN and IS being measured and will catch up to us some day.
This thread has been hi-jacked long enough. I am done.

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