235 Engine Oil Leak

[53chevy3600]

I have a replacement engine in my truck and have an oil leak that I need help with. Does anyone know where I can get a detail picture of an engine block for a 235 engine? The engine block is number 3769716 and the block has a small hole on the side of the casting near the oil pan. The hole is located just behind the fuel pump mount. Oil comes out of the hole while the engine is running and stops when the engine is off. It is maybe 3/16 in diameter and I don't think it is threaded. Thanks.

[Deve]

That is on the Distributor side which makes me scratch my head even more. I went out to the shop and looked at several of those 58-62 235's and there is no reason for that hole to be there. Maybe Dave knows something I don't, but it is never a good idea to have a hole open to the oil system and especially one with no 'boss' (or reinforcement cast) around it. Best thing I can think of is to tap it and put a plug in. This would make me paranoid or nervous that the previous owner was damaging the block to tell him not to use it again for some reason. How is oil pressure? Is there oil getting to the rockers okay? If the engine is fine, then plugging the hole will end the issue. Never heard that one before! Be sure to collect all the metal shavings if you tap it. There is no good way to do this without dropping the pan.

[Pre68Dave]

There will be two holes in the block, which I have marked in this picture.
The screws that go in there hold a oil deflector baffle which prevents oil from splashing out the road draft tube.

[53chevy3600]

I found the two holes you have shown above. The bottom hole is open and it is the one that leaks oil when running. I can't see any threads in the hole. The top hole you show in the picture has been plugged with something.

[53chevy3600]

Is it possible for me to call you right now?

[Pre68Dave]

Check your PM

[Deve]

Yep. I knew Dave would see it. That baffle is very important, so its good you found it. Those holes are not threaded and require a sheet metal screw backed with the baffle. Thanks Dave! All mine are plugged with the screws!

[Deve]

Here is what the baffle looks like from the inside....

[53chevy3600]

Thank you for your help and pics of the baffle and the information on the open holes.