Rear main leak, possibly?

[Wes Harden]

@TJ1978 if it's just a few drops, I doubt you will need to add oil often, maybe never between oil changes.

Sealing a gen 1 SBC is always difficult. The tin needs to be straight, intake angles change, when machined.
The rear main is an obsolete design, that is weak at best.
You are on the right track, start looking up high and work your way down. If your valve covers look wet that is probably it. I never used to use silicone with a gasket. 1 or the other never both. In recent years I use a super thin coat of silicone on both sides of valve cover gaskets. Makes them a bitch to remove if needed, but no leaks.
1 of benefits of higher emissions standards on modern cars, was oil leak were eliminated.

 

[Wes Harden]

GM expected a gen 1 SBC to use oil and iirc 1 quart in 3k miles was acceptable.

 

[TJ1978]

GM expected a gen 1 SBC to use oil and iirc 1 quart in 3k miles was acceptable.

Right, hence the weep hole on the bottom of the dust cover. Still, when running it’s more than few drops. But I’ll investigate further. It’s just aggravating... hahahahaha

 

[Wes Harden]

If it leaks more when running, Do what Bent said put a wrench on oil filer snug it up. If for some reason the filter was changed and the gasket from the old filter stuck to the block and new filter screwed on, guaranteed to leak. Maybe ? Who did the last oil change ?

 

[TJ1978]

This is a fresh filter. But I’ll give it a snug-up.
The engine hasn’t even had its first oil change since it was rebuilt, the engine has about 200-300 miles on it. You can see how clean the oil is in the pics.
@Wes Harden

If I can’t locate it, i may just spray brake clean, then dust it with baby powder to see if that helps locate it.

 

[Wes Harden]

the oil filter adapter has a gasket and two bolts that could be the cause also.

 

[TJ1978]

I wonder if I should pull the filter, I have a replacement. At that point I might as well just change the oil.

But I’ve been instructed to run the engine the initial 500 miles before changing the oil. Meh, we’ll see I can just get another filter when ai change the oil.

 

[Bent77]

Filter looks black, like a wix. I usually have to crank those harder to keep from leaking

 

[Bent77]

I wonder if I should pull the filter, I have a replacement. At that point I might as well just change the oil.

But I’ve been instructed to run the engine the initial 500 miles before changing the oil. Meh, we’ll see I can just get another filter when ai change the oil.

Just spin it off and take a peak, spin it back on. Won’t hurt nothing

 

[TJ1978]

Filter looks black, like a wix. I usually have to crank those harder to keep from leaking

Yes WIX... I will once I get home. Sometimes I think my ocd for perfection doesn’t mesh to well with these trucks.. Hahahaha

 

[Bent77]

Nah, you’re just learning the quirks...

 

[TJ1978]

...
Looks normal to me... other than that burr looking thing on the mating surface...

 

[TJ1978]

...
Wix 51061

 

[TJ1978]

Pulled dust cover and nothing of any significance was found... I spied as close as possible, oil pressure sender, distributor, intake, valve cover and wiped everything down that I could reach.
Put oil filter back on as tight as I could.
We’ll see.

 

[centexk5]

Isn’t that bur right where the gasket sits?

 

[dyeager535]

Yes it is. That looks to me like it's been welded in the one pic...

Could be seeping through the weld, even if the uneven surface isn't the culprit.

 

[TJ1978]

Yes... the gasket is supposed to mate with that surface. That little bit of a burr or “fix” on a mating surface, if experience teaches me anything, could be enough to cause that...

I could probably file it down a bit to make the “fix” or whatever it is more flat.

Is this what is meant by getting a “budget” engine locally and not going to summit or west coast engines?? Hahahahahahaha

 

[dyeager535]

Yes... the gasket is supposed to mate with that surface. That little bit of a burr or “fix” on a mating surface, if experience teaches me anything, could be enough to cause that...

I could probably file it down a bit to make the “fix” or whatever it is more flat.

Is this what is meant by getting a “budget” engine locally and not going to summit or west coast engines?? Hahahahahahaha

One of the many reasons I went with a GM crate (back when they were half the price they are now). You just have no idea what has been done to a used block. Normally no problems...then this. I can't imagine why that would have ever been welded there. Who messes with the block there??

I'm not sure if the rods were bad or what, but trying to braze a couple of fittings that dealt with oil under no pressure simply would not stop leaking. The only thing that worked, was epoxy. Just an FYI, if that turns out to be a nightmare (thats a terrible surface in the first place to work on trying to smooth out, and upside down?), might be able to grind it down a bit, then skin it with epoxy.

I suppose you could make a tiny little sanding block to attempt to smooth it out evenly.

 

[Wes Harden]

Emery cloth on a block. I don't like the looks of that.
That block might need to have the oil filter over tightened, to not leak.

 

[Wes Harden]

Looking at it again the bottom picture, looks like was filled in to oil gallery.

So I am thinking remote oil filter. If the adapter can be made to seal on that block. If so then you don't need to worry every oil change.