Re: Connecting Rod Alignment?

Posted by Owen_Dyneto On 2008/4/8 8:08:49

I believe that all Packard in-line Eights were 9 main bearing engines until the advent of the "120". Also in rebuilding you might want to take note that Packard had a change of heart about the positioning of the connecting rod bleed hole, this is covered in the 33/34 Service Letters. To paraphrase, "prior to the 9th series motors the connecting rod oil bleed holes were on the "leading" or oil filter side of the engine; starting with the 9th series they face the valve-side and subsequently the size of the bleed hole was reduced in size from a #30 to a #56 drill size for better oil control. However the rods shouldn't be switched in the earlier (than 9th series) motors because the bleed holes will not align with the crankshaft at the proper timing."

Just a note on pistons, the originals were "autothermic strut" design which have entirely different expansion characteristics than cast or forged pistons. When using replacement pistons, the original Packard piston skirt clearance specifications should be ignored and those of the new piston make used. Cast or forged pistons also require different clearances. Expansion slot on the valve side of the engine is the general rule for L-head engines.