Talked to Patrick today. He told me to talk to TomL about his mini HEI. TomL and I went over all of the critical dimensions of the mini HEI, and all of them were in spec. So TomL says its a fault of the oil pump or engine block.
TomL says the top of the pump takes the dist gear thrust, and that if there was a problem it was due to the oil pump allowing the dist gear to fall below the centerline of the camshaft gear. Then the camshaft gear forced the dist shaft into the pump harder than normal.
Both Patrick and Tom questioned me about the oil pump mount, and if it had ever been removed. AFAIK, it has not been tampered with. Both agree that if the oil pump mount is ever removed, the block is ruined. The factory installed a rough casting there, then broke off the bolt heads on purpose. Then a special boring machine would line-bore the block and oil pump mount holes true. The after the deburr operations, the block and oil pump mount are mated forevermore.
One thing TomL mentioned is to check the alignment of the oil pump mount by using a new oil pump and my existing HEI dist with bad gear still installed. Put some prussian blue or layout red on the bottom of the gear and install in engine. Rotate motor while pushing down on rotor to assure contact between gear and pump body. Remove distributor and examine the top of oil pump for even contact between gear and pump. This will show if the block or pump body is somehow out of line.
TomL seems to think that a new pump and dist gear will get her running again, as long as there is .010"-.050" installed endplay between dist shaft and pump casting, and dist gear centerline stays above cam centerline.
This is so weird. Can anybody make sense of this?
chip :confused:
