Re: The Duchess Project: 1940 Super 8 Convertible Sedan

Posted by HH56 On 2014/6/7 14:02:20

The plumbing Joe has was described in Service Letter 15 #12. Joe has a later engine and the oil return hole was already present since it was added for 20th series production. Prior engines needed to have the return hole drilled and those instructions are also in that SL.

When Packard first went that route, they just rerouted the lines but used the full flow filter fittings already present and still had issues. In a later SL (15#19) there was a restriction orifice to be placed in one of the fittings to limit flow thru the filter. IIRC from a later bulletin it worked out to approx 10 percent to the filter and 90 percent to tappets.

To go to that partial flow plumbing you will need to have the extra return hole. Without it you would just be feeding pressured oil to both sides of the filter and unless one side has a slightly lower pressure or resistance, doubt if you would have much if any flow thru the filter.

The one thing that is still strange is your engine went all these years without difficulty and with apparently quiet lifters so what changed all of a sudden.