This is a follow up on a previous post I did on an oil leak I had on my 68 327/350 (original block, rebuilt).
Joe Lucia, you may recall this as you gave me some good advise on this....
"In the area directly over the oil filter boss on your block are 2 threaded holes. One of the holes is for the clutch cross shaft inner ball stud. This hole is "dry" and does not go through to anywhere but cast iron.
The second hole is roughly between the oil filter boss and the ball stud boss and tapping. This hole is taped for a 1/4" NPT pipe plug. Usually, an indented square-headed pipe plug is installed in this hole. This hole DOES go through to the oil gallery and pressurized oil will be found here. This plug usually gives no problem and is not generally removed even when the engine is rebuilt.
This could be where your engine is leaking oil from. If it was leaking and someone decided to use an external application of JB Weld to cure it, that would be a VERY temporary fix. JB Weld is great stuff, but it's not going to seal in this sort of application. Your best bet is going to be to remove the epoxy and the plug and check out the threads in the block. If necessary, these can be repaired with a special Heli-Coil insert for pipe thread or the hole can be re-drilled and tapped for the next larger size pipe plug.
If you do have a crack in the block, I DO NOT recommend repair by welding. To have any chance of success, at all, welding needs to be done in a very specialized way and using ovens for precise heating and cool down. I still wouldn't do it unless there was no other way. Pinning is the safest and best repair method for most cast iron block and head repairs. In this method, special tappered, threaded pins are used for the repair. The crack line is drilled and tapped at one end and a pin installed. Then, an overlapping hole is drilled and tapped, partially in the first pin and partially along the crack line. This process is repeated until the entire crack is "removed". This is a job for someone who has great experience and skill in doing it. It's also quite expensive because a lot of time is involved."
Anyway, what I came to find out today, after removing the JB Weld, was that there was a small plug (a mini "freeze out" type plug in the hole that was leaking, and covered up with JB Weld).
It was a "stepped" hole, shouldered, to stop the insertion of this plug after it was inserted. It was not a tapped hole for an NTP pipe plug.
Well, we tapped the hole and used an NPT type plug to seal it, and that worked out OK. Thank God it was not a crack in the block.
Just wanted you to know what I found on my engine when I went to repair it.
Joe, thanks again for your advise on this,
Rich
Joe Lucia, you may recall this as you gave me some good advise on this....
"In the area directly over the oil filter boss on your block are 2 threaded holes. One of the holes is for the clutch cross shaft inner ball stud. This hole is "dry" and does not go through to anywhere but cast iron.
The second hole is roughly between the oil filter boss and the ball stud boss and tapping. This hole is taped for a 1/4" NPT pipe plug. Usually, an indented square-headed pipe plug is installed in this hole. This hole DOES go through to the oil gallery and pressurized oil will be found here. This plug usually gives no problem and is not generally removed even when the engine is rebuilt.
This could be where your engine is leaking oil from. If it was leaking and someone decided to use an external application of JB Weld to cure it, that would be a VERY temporary fix. JB Weld is great stuff, but it's not going to seal in this sort of application. Your best bet is going to be to remove the epoxy and the plug and check out the threads in the block. If necessary, these can be repaired with a special Heli-Coil insert for pipe thread or the hole can be re-drilled and tapped for the next larger size pipe plug.
If you do have a crack in the block, I DO NOT recommend repair by welding. To have any chance of success, at all, welding needs to be done in a very specialized way and using ovens for precise heating and cool down. I still wouldn't do it unless there was no other way. Pinning is the safest and best repair method for most cast iron block and head repairs. In this method, special tappered, threaded pins are used for the repair. The crack line is drilled and tapped at one end and a pin installed. Then, an overlapping hole is drilled and tapped, partially in the first pin and partially along the crack line. This process is repeated until the entire crack is "removed". This is a job for someone who has great experience and skill in doing it. It's also quite expensive because a lot of time is involved."
Anyway, what I came to find out today, after removing the JB Weld, was that there was a small plug (a mini "freeze out" type plug in the hole that was leaking, and covered up with JB Weld).
It was a "stepped" hole, shouldered, to stop the insertion of this plug after it was inserted. It was not a tapped hole for an NTP pipe plug.
Well, we tapped the hole and used an NPT type plug to seal it, and that worked out OK. Thank God it was not a crack in the block.
Just wanted you to know what I found on my engine when I went to repair it.
Joe, thanks again for your advise on this,
Rich
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