Been following along and it looks like you found the problem, but that brings up the question, "why no squeeze?" Wrong head bolts? Something wrong about the rocker stands? Major cut on the head or deck surfaces? You could use some dimensions off of a stock block and heads. What are the casting numbers of the block and heads? I have a couple of stock 392 heads that I might be able to measure for comparison.
I will toss a head up on a block, sans gasket, put the rockers on and send the bolts down, gently. I want to see how much of a gap is left when they are touched down. It would be hard to imagine that they are so close in tolerance that a few deck cuts stops the party.
Good question. That would be to where the blunt tip of the bolt would hit, not to the tip of the drill point.
To end the potential issue of gasket squeeze just go ahead and use Hardened washers under all bolt heads. That will take care of that. I keep going back to post 1 where it's said it ran 10 to 15 min up to full temp with no issues and there's no water in the oil. I have trouble believing that without proper squeeze those gaskets are still in good shape. They should be shredded or at least visible signs of leakage. A lot of good points made here so far but I just can't get my head around the condition of the gaskets. I'd take them with me when I go to get the heads and show them to him and listen to what he thinks about them.
I just made it down to the shop, so I'm going to start measuring things, while I was there looking for parts to snack up, I found this: Granted, it's for a 354 but Chrysler chose to use every single hole, not just some of them. They had a reason, not sure why the aftermarket decided that fewer of them should be used.
Here are my measurements: Blind head bolt holes: 1.31" average. Head hight: 4.10" The block and heads appear to be broached, not fly-cut, so I suspect that they are original. This engine had OEM steel shim head gaskets. I am able to bolt down a head, via the rocker assembly, without bottoming the bolts, without any gasket. About the only one thing that I can figure is that his block is not drilled as deep, but it was ok in the original configuration. After it lived its first life, subsequent fly-cuts might have pushed it over the limit.
I was always told that Chrysler didn't " broach " any heads or blocks on this engine series , but I don't know that as fact. Passenger car heads with the water outlets in the corners may not use all of the holes as the earlier style ( and truck ) . Man , I remember conversations of specifics on these engines from years ago but they get more distant every day , lol.
Brought gaskets to the shop. He seems to think they were not compressed as they should be. I told him about the bolts appearing to have touched down and bottomed before proper torque. He agreed, at least until he can start testing the heads. I can’t do any measurements with heads/bolt length until I get them back. I drained oil today and found some water in there. Now I did spill a bunch of water into the cylinders when I pulled the heads. My buddy was over when I pulled them and reminded me that a bunch of water dumped in cylinders when pulling heads and had probably leaked down. We did bore scope each hole before pulling heads and no water appeared to be in there. The oil was not milkshaked and there was a definite separation of oil and water. Like I mentioned before, no trace of water on dipstick at any point during this whole deal.
Well, I don't know any other process that would produce parallel lines running the long way down both the block and the heads that I'm looking at right here. There's not a single indication that a rotary cutter of any kind was ever used on any of the stuff that I have sitting here.
If all other things are equal, you have an un-machined block deck. That said, I would wager that the heads have been cut.
I just measured the hole depth from the top of the rocker pedestal, to the bottom of the threads in the hole in the block. In each case I came up with a depth deep enough to take quite a bit more than the whole bolt. I cannot imagine that it would be possible to mill that much off of the heads without finding the water jacket, or having the domes top out in the chambers. Not sure what is happening.
Yeah I just measured pedestal, added block hole depth and used your head measurement. With that the bolt would not bottom out... machine shop said he’s going to check the valve seats and make sure they didn’t punch into a water chamber while machining. If the heads come back good, I’d say it’s gasket failure. With the lack of compression of the gasket and the head that really didn’t seem to have sealed to the block/gasket, gotta be it?? No spray was used and the old gasket was put in dry...... waiting game right now.
Possibly those marks at bottom of bolt holes are from someone using a thread chaser and leading you in the wrong direction. Eddie
Eddie, I concur. At this point, my advice is to put the heads/rocker stands back on the engine without the head gaskets, put bolts in each ends of the heads to make sure the heads don't fall off on your feet, then check the depth of the head bolt holes using a length of Oxy/Acyt welding wire. You want to try and "hook" the wire on the block surface where the head bolt threads start. Mark the wire using tape or a three-cornered file, then push the wire all the way to the bottom of the head bolt hole, then mark the wire again. The two marks on the wire will tell you the proper shank and thread length for the head bolts. Now copper-coat the used head gaskets, re-install on the engine, bolt down heads, and torque to spec. Pull the water pump, make steel block-off plates for where the water pump was bolted to the block, putting a tire valve in one of the plates. Contact whoever manufactured your bolt-in freeze plugs to find out how much pressure they can safely hold. Using shop air, pressurize the block, listen for escaping air.
I agree on that. On what I measured, the head would have had to be milled somewhere between 0.375" and 0.625" to allow a bolt to bottom out. Pretty sure it would no longer be a head, but a cutaway display model of a head then.
Before pulling heads I made pvc caps that I put into the radiator hoses. Charged it up to approximately 40psi. Listened and sprayed soapy water all over. I only found the water pump plate gasket had a small leak, nothing else around heads/intake/block
We are into the section of the map that says here be monsters. I am lost. Maybe a bore crack, and the piston was up at the top of the bore when the test was run. I just don't know.
Maybe time for a recap, at least for me, after seven pages. No water mixed in oil says no internal cracks. The oil pump is a very good blender. You air-charged the assembly before any disassembly? Before finding the wonky head gasket? and only the minor leak? If it held 40psi then the bubbles when running is the mystery except that bubbles of this nature are usually tied to the exhaust and you confirmed that so where is the gas leaking in only one direction?
I keep thinking this is a Plugged cooling system. I say that because it acts like a blown head gasket yet neither of them have a clear sign of it happening even with minor crush. I keep remembering a cooling issue brought to me back in 1978. A model A sedan with a known to be good SBC set in wet and running out of another vehicle, instant Gyser. New Rad and hosses were all that was different to the cooling system. The stat was checked and proven to be good by customer prior to coming to me. He had not flow checked the Rad but was sure it was a faulty unit. I removed both top hose clamps and left them connected to the motor. Lifted the Rad out and proceded to flow test it. It moved plenty of water. Walked back over to the car and there it was. The rad came with caps on both outlets on it. Bottom one stayed in the Box when lifted out, he didn't notice it. The top plug was lodged in the top hose. It was Black plastic. End of problem. It never makes sense until you find it.
When was it last checked for calibration? What did torque them to? My service manual says, and my practice has been 85.
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