Hot Rods 392 hemi overheating

In reading the opening post you say it ran at 195 for 10-15 min no problem. Next run it blows a soft plug. I feel if you had re torqued the Head Bolts before you started it the second time you wouldn't have this issue. I have some doubts about the motor builder when I read it still had Factory soft plugs in the Block still. That's second guessing on my end. Any good builder would remove all the plugs and Tank a block. Everything you've told us points to a Head Gasket or a freeze crack in a Cyl. or Head chamber. At any rate your not going to cure it without starting to take things apart checking everything as you go until you uncover it. Any good builder that builds a motor for sale, starts and runs it in should start and run it for the new owner. Past that you may have bought it with a problem the builder was not able to cure, sold it instead of scraping it.

 

I should have added that none of the tests you did point directly to a Head Gasket. This is why I added and agree with junkman8888 on a possible split Cyl wall of fractured head casting.

 

Oh man I hope it’s nothin major. Gonna grab some pvc plugs and a scope today. Start the search and eventually tear into it...

 

Regardless what more testing shows you have compression getting into the cooling system. This means at the very least removing both heads, maybe more. Bad as that is to accept, I'd just get after it. Slow and easy so you can read all the gaskets and I hope you have straight water in it, might leave you a rust signature where the major issue is.

 

Before anything I'd still pull head bolt torque just to see what happens. That could tell you a lot.

 

It’s definitely coming apart, I figured another test won’t hurt to narrow my search. But definitely a slow tear down and inspection...
Heads were torqued at 85

 

Ratz! was hoping you would find a few around 55-60.

 

Same thing my buddy said. If I didn’t have bad luck, I’d have no luck... haha

it’s hot rodding, gotta pay to play. Sure should be nice if disability didn’t cut me off this month though haha!!

 

It sucks to have to pull it down but, at least you will be able to do a better job of inspection.
Head gaskets are not horribly expensive, in fact, I'll send you a pair for $30 to help ease the pain if it helps.
[email protected]

 

Your post emphasized "SHORT" (in a capitols only shout out) , which long or short "has no bearing or relation to what the original poster has, or is doing".

 

It has everything to do with it.

He has a short pump. Everyone mentioning reverse rotation pumps is talking about a long pump, even if they don't know that.

Did you miss that?

 

Head gasket or crack, I believe that this needs to come apart.

If you can get, borrow, rent a borescope, I would have a look in the cylinders for any anomalies.

 

Mighty generous!

I will see if I have intake gaskets.

If it is a head crack, I think I have a spare set of 354 heads. They would need freshening, and some manifold spacers.

 

Other than having the proper direction long BBC pump on a previous 331, never had dealings with Chevy stuff. So they don't have reverse on short pumps? Didn't know that.

 

Does the 392 have oil pan studs to go into the water jackets like at 3:31

 

In GM-land, reverse rotation pumps are a serpentine belt-era thing, circa 1987-ish.

Long pumps started circa 1969-ish.

Corvette had its own ballpark, due to tight fitments.

I suppose that there might be someone making a street roddy serpentine system with a proprietary short pump. I don't mine those product catalogs.

 

I don't believe so. I will check when I get to the shop.

 

Heads are off. Nothing jumping out at me. Gaskets actually look fine. Gonna look into cylinders next.

the drivers side head was difficult to take off as it should be, but passengers side lifted after bolts were out, like if it wasn’t for the pins it would have slid off.

 

Check the decks and make certain the fire rings were sealed good .
There should be a nice witness ring showing around the cylinders if the gaskets were sealed good .
Tommy

 

Seem good, at least nothing crazy obvious. I’m thinking have the heads leak tested for cracks.

 

What do the tops of the pistons look like?

 

6 are nice and new looking, 2 are used. The 2 have little scaring on top. 60 over.

 

Check the fire rings carefully for cracks, use a magnifying glass.

 

For less than $40 this is a great tool

 

Take i long straight edge and check both your heads and block deck for warping. A slight warp can get worse with heat.

 

Might want to make sure those dowel pins aren't too tall . It's odd that the head gasket didn't seem to bond like the other side.

 

Both of those things concern me, as well.

They should have released the same way on both sides.

 

I just checked a 354 and a 392.

Every hole was blind, so this may have been a 331 thing.

 

I would.

Have them checked for flatness, too

 

Wish I was close enough to come look over your shoulder. The answer you gave me about good water flow keeps coming back. You said something like pulling the sending unit out and water came out. That's probably not how I would have put my mind at ease.