Nothing like a milky discharge to ruin a weekend!

[moparman82]

Ok so, my brother's 340 demon has been smoking a lot from the drivers side exhaust and also is spitting out a really viscous oil/coolant mix.  He brought it over today and i checked the oil, really milky, so obviously coolant in it, pulled the valve cover first and found a broken rocker on the intake valve of the cylinder closest to the firewall on the driver side.  Then i pulled the heads and found more milky crap in the same cylinder.  Any ideas?  The head gasket seemed to be fine, but there is obviously an issue, the  valley was full of puddles of milky sludge wherever there was a low spot.  WTF?  Thanks

FYI its a 70 340 block and 73 J heads

[moparman82]

cylinders

[moparman82]

Close up

[Skunkworks Challenger]

Looking at the pictures I think I see liquid in all four cylinders?  Must be a cracked intake manifold.

[Chryco Psycho]

could be as simple as a bad head gasket , I have seen rockers fail before .

[72cudamaan]

Definitely a problem in #7 cyl. The piston is washed. You didn't pressure test the cooling system
 before you removed the head did you? Any pic's of the gasket?

[72cudamaan]

It also looks like the head bolt at the 10 o clock position of #7 may have been loose or
over stretched. Seems awfully clean there compared to the rest of the deck.

[moparman82]

Dont have a pic of the gasket, already tossed it, looked good though, couldnt find any flaws in it, i will have to look into the manifold, didnt think of that.  Could the head be cracked?

[72cudamaan]

Looking at the pictures I think I see liquid in all four cylinders?  Must be a cracked intake manifold.

I assumed that coolant came out of the head when it was unbolted. Was the coolant drained before the head was
taken off?

[moparman82]

I assumed that coolant came out of the head when it was unbolted. Was the coolant drained before the head was
taken off?

You would be right Cudmaan, coolant came from the head, however, when the head came off initially, the 2 cylinders to the left had bright green coolant, the third had a little bit of coolant/oil mix floating on top of clean coolant, and the last cylinder had only the milky mix

[Chryco Psycho]

The head could have a problem & is worth checking but I doubt it , sometimes it can be a simple as dirt in the threads & the head bolt reached torque before it clamped the head down

[moparman82]

The head could have a problem & is worth checking but I doubt it , sometimes it can be a simple as dirt in the threads & the head bolt reached torque before it clamped the head down

How can I clean em out without pulling the motor?

[Skunkworks Challenger]

How can I clean em out without pulling the motor?

Use a thread chaser--not a tap, then a rotary wire brush in a drill motor followed by flushing with brake- clean or similar.

[vinb]

Had a few push rods go threw those junk stock rockers, they don't like 6800 rpm's much, but in NHRA Stock rules are rules, now 15 years later you can use any steel replacement which are 99% better.

Those stock rocker ratio's are bad anyway 1.41 to maybe 1.43 that's it...

Looks like you have a bit more problems, to bad it wasn't the rockers and push rods..

Your going to that much trouble , I'd pull the engine and check everything, (don't do it twice)...

Get it fixed up..

[jimynick]

"Your going to that much trouble , I'd pull the engine and check everything, (don't do it twice)..."


What the man said. Send the head out and have it checked for flatness and a pressure and mag test wouldn't be overkill, either. You can mop out and blow clean the cylinders, but be sure to give them a wipe with a clean, oiled rag before buttoning on that head. Laying a good, known straightedge on the block and ensuring there's no more than .002" max warpage would be a good idea as well. Drop the oil and filter right away and once you get it running, I'd run it for 20 minutes and then dump it again, filter and all. Keep and eye on your oil pressure, because you may have damaged the rod/main or cam bearings running that slurry in it. If it were mine, it'd come out and apart, so that I could sleep at night.