Another early hemi question - coolant leak near oil pan area

Helping my uncle remotely with the freshly rebuilt 392 Hemi in his Chrysler again. He apparently went to put coolant in it, and it started to drip coolant from the oil pan area near the starter. Looking at pictures online, it seems like either an indexing hole or a cleanout area for the coolant passages, but I can't find any references to plugs that are supposed to go there.

Is this a machined hole, and should a core plug be inserted in it? I'm wondering if it had one installed, and is leaking now after being machined.

Any thoughts? It's the hole circled in these two pics. In that second pic it really looks like a core plug. Thanks!

Blus, is it possible that it is coming from the deck and running down there? There is a coolant hole from the deck to the head at the very bottom rear corner.

I believe the large holes are jig reference or positioning points for machining. No core plugs. I suspect the leak is at the rear core plug area. Hope it is not a crack. He most likely needs the transmission removed for proper inspection.

Joel- thank you, I'll ask him again and maybe ask him to get pics. He is in the DC area so it'll be a bit before I can get to the car again. That sounds more likely for sure. I'll have him do more inspecting!



That was my first thought as well, I thought those were only used as reference points, but the one pic looked like a core plug so I figured I'd ask.

I assume this is a coolant plug as well, circled below? The two on either side of the cam are oil galley plugs.

Yes they are. However you need to verify that older block has that style. I assumed they were a drive in plug. Might call Hot Heads.

Chrysler made three different casting of the 1957 and 1958 392 blocks, the A1 being the best and strongest, the WW, I think that was the casting letters on them was in the middle on strength and core thicknesses and the no name or letter blocks number block with weak main webbing with cast in holes between the main bearings and the bottom of the cylinder bores were the worst as far as strengths .
IHTHs

NITROUSN, I think you nailed it. He inspected further and was able to determine it's actually coming from the bellhousing area. He had a reference picture of the back of the engine before he installed it and it's the style with the two threaded plugs, it doesn't look like either has thread sealant on them.

I offered to help him pull the cast iron Torqueflite out to get to it, will go visit him next month.

Cab- thanks for the info. This is a stock rebuild, but it's a 300D so it has the solid lifter cam, adjustable rockers, and dual Carters on it. I doubt he'll be hot rodding it around much!

They referred to the 300 as the Banker's Hot Rod.

hmm,come to think of it my daughter bought a 300 and she's a VP at a bank.

Update: my uncle pulled the trans over the weekend, and it’s not looking good. There appears to be a crack below the freeze plug area. Any suggestions on how to fix this besides finding another block? The motor is freshly rebuilt so it would be a shame to pull it but I don’t think there are any other robust solutions. It’s in such a bad spot I’m not sure the pin and stitch method will work.

Sodium Silicate or Sodium Metasilicate, aka Waterglass. It was the active ingredient used back in the old days, before pepper became the preferred leak stopper upper.

https://en.wikipedia.org/wiki/Sodium_silicate

I like and use Alumanseal, grey powder sealant in a small plastic container, works great, last a long time

clean it up very well and try JB Weld. I know of a couple people who used it and held.

Can you mark or identify the crack please

Sorry, slow to respond on this! I can't tell if it's an actual crack or if the block is just slightly porous or something, but it's leaking where the blue has been colored in - below that reinforcement rib. He cleaned it off, then drew on it with a sharpie to indicate where it's leaking.

He is going to try JB Weld and then some alumaseal. If that doesn't work I'll help him pull the motor and get it to a machine shop to be welded.

They make a sealer specifically for blocks.

Might be an option

https://www.stopautoleaks.com/product/block-seal-permanent-metallic-block-radiator-seal/

Using the drill and stitch method works really well if the shop doing it knows how to do it properly
All cast iron welding should be done in a oven to get the block temperature up to the proper temps and theen allowed to cool down properly so no machining work needs to be done again due to the block warping and shifting the casting
It is his or her choice
Good luck