Re: V8 Pistons

Posted by Jack Vines On 2008/8/26 14:43:21

Hi, Eric,

That article you posted is standard balance procedure which I/my balance shop do every time. You'll have to spell out for me (us) what you wanted us to learn from it.

Here are the reasons I balance every engine nowadays:
1. Packard's balance wasn't that great to begin with.
2. I bore many 352"s to 374" and the pistons are 38 grams heavier.
3. Egge pistons aren't even close to the Packard piston weight.
4. On custom engines, such as the 364" truck engine I'm building now, everything is modified.

Putting a bare crankshaft between centers or on blocks on the bench and watching what it does/doesn't do won't tell you anything about its dynamic balance. It has to have bob weights attached to the throws; they equal 100% of the rod big end/bearing plus 50% of the piston, rings, clips, pin and rod small end weight. Then, it has to be spun to operating RPM. If it were statically balanced, it would be all wrong dynamically.

thnx, jack vines