Re: Since Packard had a V-12 in the 30's....

Posted by 55PackardGuy On 2009/8/2 16:31:03

Well, here's what I found on the aluminum vs cast iron history:

""Pistons [on the '23 model] were slotted aluminum alloy but reversion to cast iron (as in the Single Six) was made in December when aluminum was found to suffer from warpage, piston slap and wear."

Packard, A History of the Motor Car and the Company, Beverly Rae Kimes, ed., copyright 1978, Automobile Quarterly, Inc. p. 238.

I was kind of wondering about piston slap, with that 5" stroke and high piston travel speed and resulting heat, that maybe aluminum was a bit too touchy. To compensate for expansion, they would have had to undersize them a fraction, and startup may have been quite noisy, especially after some wear set in. Not in keeping with Packard standards!

Don't know when they resumed aluminum, or what changes allowed them to, but someone will be sure to get that, too.