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Rear main leak, possibly?

Yeah, I agree,, pretty sure that's your leak.
and that's not a good place to have a leak, definitely looks like a bogus repair job.

Could have been caused by some idiot hammering in a prybar or screwdriver at the rebuilder taking off a stuck filter.
Or damaged by another block or head falling on it during the scrap or cleaning process.

Is it a local rebuilder? or a mail order engine?
Either way,, I would be doing a tap dance on someone's desk getting answers NOW!
Can't believe a decent rebuilder would do crap like that and hope to get away with it, only later to push the blame off on the end user.

It's not going to get better by itself, so I would be making them aware of their crappy work now!
Document, document, document, all communications with them, other problems may come up later caused by this repair job.
I can only imagine what the rest of the engine looks like internally..

Last resort... brake clean the hell out of it, smear some JB weld on it...smooth it out the best you can, grease the filter seal and tighten the hell out of it.

Good luck !
 
Unfortunately my 1 year warranty has long since expired.
He is local in AZ. I bet he’ll say the people who installed the engine did it. Not really much I can do.

If this isn’t the main leak I’m chasing it sure is one of them.

Myvintageiron7512
This guy
https://m.youtube.com/c/Myvintageiron7512/videos?disable_polymer=true&itct=CBAQ8JMBGAEiEwjOsomxjantAhUW1sQKHSbXBGM=

I don’t have Facebook which he is on , I emailed him the pictures I doubt he will respond.
https://m.facebook.com/pages/category/Local-Business/Myvintageiron7512-1400509600164645/
 
That would be a difficult repair to do on a bare block, let alone an assembled engine. Cast iron takes special prep to weld/braze correctly. That block should have been scrapped after clean and inspection.
 
Myvintageiron7512



Seriously !?!?!

Man, I thought that dude was much better than that... really surprised by that,,, I watch a lot of his videos and kinda highly regarded him as a cut above..
That's disappointing to find out it was him..

You should still contact him, let him know you are on CK5 and lots of people are following your thread.


just my .02
 
It was either him or the shop who installed the engine for me. It’s hard to imagine him not seeing this on assmebly of the block. But, stranger things have happened and everyone makes mistakes unfortunately.

He is so meticulous and precise on his videos and builds but... you never know.

C5C5503E-025A-4BFA-B486-3D6932715B7D.jpeg
 
Still is disappointing to see. I am betting your engine runs nice and strong. This could be an ongoing issue.

https://derale.com/product-footer/f...28-09-53-27459934969/gm-adapters/35762-detail

with some judicious use of silicone and lock tight on the bolts. with your choice of breaded hoses and connectors to remote filter.

Or add an oil cooler with this https://derale.com/product-footer/f...53-27459934969/sandwich-adapters/25720-detail

double check that one, they have a small filter adapter. I didn't have time to scope it out 100%
 
The engine runs nice and I couldn’t complain, other than this.

My $$ would be on shop knocking over the engine somehow and having an “oh shit” moment and huridly trying to cover before anyone notices. Or they knew and said **** it. All of the above or possibilities.

I had another issue with this shop in regards to this engine which leads me to think it was them.

Either way I’m stuck with it. I will try and band aid it. But they way it leaks at idle, I hate to see what happen once I get moving down the road.
 
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I'd use a dremel tool with a sanding drum or fine grind stone to gently buff that lumpy area smooth..it wont be easy using sandpaper by hand ,you'll probably remove more material surrounding the lumpy area than take metal off the lumpy part..

You plan on using J-B Weld or similar putty on it after sanding it smooth ?...I'm not sure that will stay put under hot oil constantly,and it may come off of the rubber gasket next time the filter is removed..

I had a thought--wonder if you could get a piece of metal thats like a big washer that only covers the gasket sealing area for the filter,and sandwich another oil filter gasket under it ?...it may work but there may not be enough threads ,or the double gasket may blow out under high pressure on a cold start..maybe use RTV under the "washer"?..
 
I’m going to use a block or something in order that it stays level going across it.
Then fill with JB weld or black RTV then re-sand and hope for the best...

I was thinking to double gasket it but I voted against it.

I have a dremel as well. We’ll see what happens I don’t want to make it worse but it’s a chance I have to take I guess
 
A double gasket is almost sure to blow out,but with a metal washer "glued" to the sealing surface with RTV most likely wouldn't give any grief..the RTV will fill in the low spots & seal the washer to the block and the washer will provide a smooth surface for the oil filter gasket to seal up against..
One thing though,you dont want any excess RTV to get in the engine...
 
you want that surface as smother as possible. The seal surface looks bad, but I am also concerned the crack from the repair is out side the diameter of the oil filter o ring. This crack may be the whole problem.

edit none of those brushes will smooth out the weld. maybe an epoxy ....
 
Maybe the white grinding stone one in the bag would be good,it looks to be fine grit..
I bought a big assortment of those dremel tools and most of them aren't very good quality,the grinding stones usually are lucky to last one use--ditto for the wire brushes,I used up two just taking the gangren
 
If it’s really dripping oil that much while running it seems like you could see that coming from the gasket. If you really can’t see it coming from there, it would seem to be coming from somewhere else.

My 350 had a bad leak after a rebuild at the distributor and the back of the intake. The MSD distributor had an incorrect seal on it and so I swapped in a new AC delco model that fixed it. The intake leak solved by pulling it and using RTV instead of the rubber gaskets they give you.

my vote is purple power in a bucket of hot water, spray it all down so it’s clean everywhere and dry. Then tape some paper towels near some suspect leak spots and then let it idle a bit and keep checking the paper towels for oil.
 
Intake is RTV sealed. I watched the distributor and oil pressure sender while it was running and nothing of note was leaking but it’s possible. Im not thinking the oil filter is the only source but it is the main one at this point.

I guess it’s maybe coming from the back of the block somehow? But with the above said, the oil is running down the filter where that spot is. I just don’t know where else to look.

Zoom in on the picture. I’m all ears.

Oil pressure sender
Distributor
Intake
Valve covers
The oil filter

635538CF-F790-4FB6-BBDA-802413576838.jpeg
 
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Tomorrow I may just dust the back of the engine with baby powder or something and run it.

It’s weird it just started leaking pretty bad the last couple weeks, before I would drive and maybe a drop would develop over a day or so. Now it’s drips consistently while at idle.
 
you want that surface as smother as possible. The seal surface looks bad, but I am also concerned the crack from the repair is out side the diameter of the oil filter o ring. This crack may be the whole problem.

edit none of those brushes will smooth out the weld. maybe an epoxy ....

The crack “fix” since it’s hard to see once on, appears to be inside the filter gasket and outside a bit as well.

The “fix” looks wider than filter gasket surface.

E3DEA8A0-ECFF-4797-8AD1-CD6BF77BB292.jpeg

5B180B5E-8169-4944-A64C-F9D04EA09AE3.jpeg
 
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