THe machining/finish on the new valve was much better than the new replacement part. So I measured both and managed to turn about 0.0015" off the diameter of the old valve head to match the diameter of the new one and remove the witness marks. Those things are hard. Carbide barely touched the surface. I used the smallest smear of lapping compound on the angled head of the valve and thumb-lapped it into the seat in the block after making a nylon guide bushing to keep it square. After a lot of follow up cleaning I installed the new spring (with an additional thin washer), and the re-worked valve.
The cold pressure was higher. After about 1/2 hour of running the engine the idle pressure at 1000 RPM was about 38 PSI. The ambient temperature is about 50 oF and the engine coolant temp probably close to the 160 oF rating of the new thermostat. The pressure is still not what I want on a fresh engine in cool weather. However, the OP easily goes up more than 10 PSI per 1000 RPM. Raising the engine RPM to 2000 easily brings the pressure back up over 50 PSI.
I mentioned previously that I had ordered the 6-cylinder pump rebuild kit and that I have an old straight pickup 1500 aluminum body pump among my used parts. I am going to tinker with building a high-flow pump for this engine. I may or may not install the pump depending on how I feel after driving the car for a while. If the pressure stays above 20 PSI as spring and summer return I may leave well enough alone... unless curiosity gets the better of me concerning the converted/modified pump.
Doug L.
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