Re: V8 Pistons

Posted by Jack Vines On 2008/8/25 12:44:45

FWIW, I no longer build a Packard V8 without balancing it. Since we don't have good technical data, who knows what should be where.

Here are some questions for which I still don't have answers after many years and many engines. Do any of you have thoughts or references for:

1. Why do the 352" and 374" cranks have the same P/N when the balance factor is 38 grams different?
2. What is the design weight for 374" pistons? I have 352" 24.763oz - 702 g, but no published weights for 374" pistons and no pin weight. BTW, oversize pins are heavier.
3. Why were there two or three different rod manufacturers? Why did Packard mix them in the same engine when the weights are definitely different? The "Atlas" rods seem to be heavier than the no-name rods with the sort-of-pentagon-logo them.d Anyone identified any other markings besides the P/N and batch pour number?

Bottom line - yes, any rebuilt engine should be balanced. The vibration can be noticeable, especially if the pistons are changed.

thnx, jack vines