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

Posted by Owen_Dyneto On 2009/8/2 18:45:44

Any references that they suffered from piston slip or warpage? I've heard plenty of original, unrebuilt Packard engines from the mid-20s that are silent, and I've seen original OEM pistons removed that looked good enough to use again, and can't recall ever reading about piston problems. There was a service letter about 1934 suggesting that the "T" slot could be installed either way, though earlier recommendation was that it face the camshaft side of the engine.

EDIT - assuming the cite in the Kimes book about reverting to cast iron is in fact correct, I'd guess it was a very temporary measure. Packard's aluminum pistons were of a very sophisticated design, not much different than those used in all the L-8s right thru 1954.

EDIT - the pictures in the 7th series and up service letters show the aluminum 4-ring piston of the controlled expansion autothermic strut design, and states they were used from (at least) the 6th series. Perhaps Packard tried a cast or forged slug design aluminum piston, got poor results, and changed to cast iron while they quickly sourced an improved design?