No Pressure

[cst350]

OK, I am at my wits end. My truck is/was at a point that the “builder” motor that I was running was underpowered for what I wanted. I went out an found a nice high nickel 4 bolt SBC block and sent it to one of the best engine builders around. I had it clearance for a 383 crank and bored .30 over. Scat rotating assembly putting it to @ 10.1. I then put on a set of AFR heads with the same shop doing a 3 angle valve job to freshen them up (even though they were never raced) I am running a Comp XS282 Solid lifter cam. I also put in some Howard Cams EDM lifters (91118) and 8/200 push rods. Melling M55HV pump with a 7 quart pan. The pick up is a bolt on from Kevco and is 3/8” from the bottom of the pan. I plastic-gauged the crank bearings and they were all within tolerance. If any thing they were a bit tight.

After using Royal Purple breaking for @ 30min I drained the oil and replaced it with Lucas 20/50. When I fire the motor it has between 25 and 30 lbs of pressure cold. After getting up to @ 180 deg the pressure drops to almost nothing! If I drive it around the block the pressure comes up a bit (12 lbs. at 3,000 rpm) but no where near what I would call safe. The engine temp never gets above 200. I swapped the distributor and nothing changed. I tried a different gauge and nothing changed. I probed down the oil gauge hole to double check that the main bearing had the oil plug in place and it does.

Thinking maybe I should ditch the EDM lifters for traditional ones as one last Hail Marry. Other than that I guess I have to pull it. First I would check to see iff the 3 oil plugs behind the timing gear are there… then take a look at the oil pump to be sure the relief spring didn't stick.

Anyone with other suggestions before things get out of hand $$$?