Packard Forum Index » V-8 (1955-56)

The only published figure I have is:

Cranking compression 120 lbs/sq in(54.43 kg/cm) min. at 150 rpm.

Since that's a ridiculously low number, I'm guessing it could be for the 7.5 to 1 Hash engines. Even an 8.5 to 1 should have at least 140 PSI. The 9.5s around 150 and I'd expect to see the 10 to 1 374" blowing at least 165 PSI.

Anyone have any other published cranking compression numbers?

jack vines

Jack, I've browsed the usual places and likewise do not see any specifications for compression pressures; the highest compression reading for a cold engine that I got from my 374 engine (when it had about 80,000 miles) was about 155 psi.

Yeah. 120 psi is ridiculously low. Just out of curisoity where didd u see that published info???

Quote:

S-P Shop Manual

jack vines

Per maintenance records, on 09/13/2014, the CCP on the 352 in the 56J, with 94,000 miles on last rebuild, was: #1: 155; #3: 150; #5: 175; #7: 175; #2: 165; #4: 170; #6: 160; #8: 150.

Not sure what the OEM spec was but agree the spec in the S-P manual is pure hog-wash.