1954 valve timing

Posted by Ross On 2009/12/14 8:47:47

I get to drive lots of Packards in my business, and I have always felt that there was something a little special about the 54s. Clippers and Cavaliers always seemed to have more snap and be more responsive than the equivalent 53s. I was hard pressed to believe that the 5 hp difference between equivalent engines could be that noticable--and wondered also where that 5 hp came from.

There were only two basic cams supplied for the 288/327 family, either hydraulic lifter or solid lifter flavors. Even the cam for the 359 has the same timing as a 327 (per the specs in the back of the service manual), but I understand it is notched a bit for conrod clearance. Thus it gets a different part number.

Anyway, I just noticed that all the 54s other than the 288 got a new cam gear. This must be indexed differently than the old cam gear. With the old gear the intakes started to open 15 degree BTDC, with the new, at 10 degree. All of the specs are shifted the same 5 degrees.

I'd love to hear some comments from folks who know cams about the whys and hows of this change. Apparently it helped the breathing on the big engines. Wouldn't it also help the 288? I'm just building up a 288 now for my roadster and would make a stepped drive key to achieve the 54 timing if it seemed a good idea.