Never seen this before
My 48 Mercury engine was rebuilt just before I purchased it. One thing that bothered me was that the heads were not 59AB heads. I found the correct heads at Hershey a few years ago and installed them. I was also curious to take a look inside the engine. The engine was re-bored .060 over and clean as a whistle. I also adjusted the Johnson lifters.
The car runs great but I always noticed the oil pressure was on the low side. The car is in my shop for the winter and I have heat, so a couple of weeks ago I decided to pull the pan and take a look at the bottom end. I had sort of convinced myself it would be a waste of time and I would probably not find much.
I noticed the pick-up tube on the oil pump moved back and forth a small amount but the two 1/4 in. bolts that attach it to the pump were tight. I looked further up and saw a break in the oil pump housing just below the bolt that attaches the pump to the block. So the pin in the drive gear for the pump was all that was keeping the pump for falling to the bottom of the pan. Obviously this is where my oil pressure was going- through the broken housing.
It was the old style long pump and I found a NOS Melling USA made helical gear short pump. I had to change the pick up tube to match the newer style oil pump. I bet the oil pump housing was broken and no one ever noticed it or the engine got dropped during assembly. You really had to look close and twist the housing to see the break. But regardless of how it broke, I have good oil pressure now and I sure am glad I dropped the pan to take a look-see!
Bill in Connecticut
|