I have two holes in the back of my block on the top just in front of the bell housing area. Oil is coming out and I cant figure out what is supposed to go there. One hole is a 1/4 dia and threaded. I can throw a bolt in that one. However, the other hole is smooth and the wall is thin. There is a cavity area just beneath the opening. In 4 secs of cranking I dump about a qt of oil. I have been told that an oil sending unit goes there but I have never seen one that uses two holes. I am wondering if I left out an internal oil plug. Any ideas? see pictures:



This picture is from a 350 block.


I can physically see oil coming out of it while im trying to crank the engine. I have lost about a qt so far.

 

Neither of those holes has anything in it, most of the time.

There's basically NO WAY oil can be coming out of those, because they are, for all practical purposes, "outside" of the block. Look closely and observe that if they were drilled all the way through, they'd be going into the bell housing. The block would have to be TOTALLY TRASHED in some never-before-seen way, for oil to somehow be at that spot.

But...

Are you POSITIVE the oil is coming from THOSE holes? Look at your pic: there's a brass plug where the oil sender goes, and then about an inch and a half closer to the camera, right at the very corner of the head, there's a hole in the deck that DOES require a pipe plug. You can just barely see the little round place in the pic. Is there a plug in that hole? If not, pop the head back off and put one in there.

 

x2....This is what he is talking about.

 

Look like oil gallery bore holes. They need to bore oil the oil galleries after casting. Once the gallery is finished, the hole is tapped and plugged. I have a few of them like that on my Dart Big M block.

You can either just plug it off or stick an oil pressure sensor in it.

 

The holes in the fist pictiure were used in the 60's 70's and have been there since the beginning ( I think). They were used to hold an L-shaped bracket with a four wire loom that prevented the spark plug wires from touching the exhaust. At the other end of the bracket there was a 1/4" tab bent 90* to fit in the blind hole and a 1/4" screw to hold the bracket in place. I use those holes for extra ground straps from the block to the body. Today there are better wire looms that dress up the engine compartment. If I find a pic of the original usage I'll add it. And I agree with sofakingdom, no way you get oil out of these holes.

OK, found a thread that shows exactly what and how they are used.
http://www.stevesnovasite.com/forums...d.php?t=154020