Re: Frozen piston

Posted by Let the ride decide On 2010/9/15 21:30:27

I am not a engineer, but the pump design has issues. The shaft connecting it to the distributor is a 2 piece design with a collar. The shaft is only supported at one place, and it is just a cast support, not a bushed support. You can just imagine the spinning and wallowing out of this area. A good place for air to enter the oiling system.

Some pumps had 2 places for support, when the vacuum pump was on the fuel pump. The PI fix was based on this idea.

The fix that Bob Aller used was to install a bushing in the top cast area, and a new lower shaft. He built a testing plate with a place for a gauge to test the pressure.

I believe this is how Terrill machine repairs the pumps as well.