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
 
great repair you took your time and opened every door. like the old saying if you take it appart and don’t find anything you wasted your time
 
Also fits in with the saying: If you want something done right, do it yourself.
Good catch and good job !


Sal
 
Appreciate all of your comments. I usually rebuild engines myself, but this 48 Mercury convertible had the engine rebuilt before I bought it. Like all of us "motorheads" I was curious to just how "rebuilt" it was. When I pulled the heads I was really pleased to see it was a full and good rebuild. That's why I was questioning why the oil pressure ran on the low side. I thought I might find the old style straight gear oil pump and maybe it was worn. The busted housing was a surprise but the second I saw it I knew I had found the problem.

The Mercury convertible is a fun car and a real keeper. It's black with a red leather interior. Probably not a show winner but it is a real nice driver. I've been tweaking it for a few years and now have it where I would not hesitate to drive it anywhere. Really enjoy the folks at the Ford Barn.

Bill in Connecticut
 
Love those 48 Merc convertibles and you have the right color combo's ! Great find on the oil pump problem! Enjoy ! Pictures ,please !
 
It's never a waste of energy doing things like that. If nothing is found, you at least have the assurances all is OK.
 
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