Re: engine balance

Posted by PackardV8 On 2015/10/24 17:29:52

Crankshafts:
Take ANY counterweighted crank from ANY mfg'er of engine (assuming auto or lite truk application) and place it on two SIMPLE TO MAKE knife edges that are leveled.

The crank can be rotated to any radial position and it WILL STAY IN THAT POSITION!!! It is a FACTORY balance of the crank, exactly the crank and ONLy the crank with absolutely NO consideration for piston weight.

The counter weights exist to counter the thorw of the rod journal.

OK. Now, bore the engine for real heavy or real lite pistons and butcher up the counterweights crank all in the name of "balancing" annd then the crank will no longer stay on the knife edges and will rotate to the position where the rod journal of the crank is at the BOTTOM unless weight added t o crank counterweights then crank will rotate with rod journal to top.

Upsetting the crank balance.

Piston weight has absolutley no bearing whatsoever on crank balance. Neither does rod weight. OTHERWISE the crankshaft of a production engine would not stay at ANY poisiton on the knife edges.

Disclaimer: my above decription does NOT apply to 1 cylinder nor 2 cylinder engines. ONLy applies to 4 or more cylinder engines.

I don't know about 3 cylinder engines.