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The PASB’s indicate that there were 2 lifter designs, the original used on ’33-’35’s and the second ’36-’38 which was adapted by Packard and Cadillac and late ’40’s. I think there were three.
The PASB 70-1 says the two designs can be distinguished by the second one having exposed springs on top and a diameter of .7182. the first design has the spring inside and a diameter of .6875. There are several articles on rebuilding the first design, the second design is interchangeable with the later Cadillac units and available from Egge – although it may require building new plunger caps.
My ’35’s seem to be an intermediate design. They have the exposed spring on top like the second but have the original plunger diameter so they aren’t going to interchange with the Cadillac. Basically they are a variation on the original design, so I think lapping the ball seat per the first design is in order if leaking.
It does beg a few questions for those who have rebuilt the originals. The PASB’s say the seat is conical and to cut the end of a brass rod to use to lap the seats by hand. The seat on mine is iron or steel and does not look conical, were the seats on the first design brass? I will probably start with a round steel screw head as a lap to cut the seat slightly.
One of the original Pierce-Arrow bulletins says that the test for leakage by blowing on the end with it immersed in gasoline should be done wit a drop of gasoline on the ball and a slight amount of air bubble is acceptable. On mine this could be the difference between taking them apart or leaving them alone (always my preference). Any words of wisdom on how judging the leakage?
Thanks for any help!
Jim
Hi Jim, I’ll look and see if I have a lifter that is apart. From memory, I think the seat was rounded or a concave surface. Hopefully I’ll find a disassembled lifter.
Greg
Greg, if you have a dis-assembled first design dis-assembled handy I would like to know if the seat is brass and conical- but not worth a lot of effort. I am pretty well stuck with dealing with what I have one way or another. My first pass at cleaning up the seat wasn’t good, looks like it has a defect right under the surface- although extremely hard to see because of the problem of getting light down the hole to see with a magnifier. I may end having to machine a new check valve seat to thread into this body to salvage it, and brass will be a lot easier to machine. In all likelihood even though it leaked a bit it would have been okay as is, but I have crossed the Rubicon now.
Fortunately the next three lifters seen in the picture passed the leak test easily and I won’t have to mess with them.
Thanks! Jim
Jim,
Wouldn’t a brass seat pound out of shape and leak again?
When I made seats for the shocks I used a ball mill and the matching ball bearing. Jim
Just because it passes the leak test on the bench doesn’t mean it is good. In my 36 V12 I had to replace three lifters in less than 200 miles after the rebuild. It’s possible the balls have pits and only rotate over a length of time.
The ball in this first lifter was actually in pretty nice shape, no evidence of wear except the faintest scratches. Replacing it with a new ball didn’t help the leakage. Certainly that doesn’t mean the rest are good and I will check them out as best I can. Fortunately this car had relatively few miles on it and so far no evidence of any corrosion in the lifters.
Rather than build a complete valve body to insert into the plunger, my first attempt will be to cut & lap a new seat in the existing per the original, then fabricate a threaded insert to retain the ball instead of the cross pin. By cutting a new seat a bit deeper, the original cross pin to retain the ball might give the ball too much up and down motion, so I think that needs to be adjusted for.
The trouble and risk this entails is why I don’t take things apart unless necessary. The odds of it being better if messed with are not necessarily better than if left alone.
Thanks, Jim