I did check the dowel height but will double check after the heads more than likely come off. I've just bought a Best gasket kit and a coolant system pressure tester. Thanks everybody for the tips and letting me know where to start to diagnose my leak.
MoPar/Dodge used to make a sealant called Mopar Black or Dodge Black, can't remember. Best stuff I ever used, above water or below, marine or auto. I can't find it anymore under those names.
You must pressure test all these old blocks. My hemi was ready to fire when I noticed the coolant had leaked into the oil. Two soft rotten areas of cast iron, which is not detectable by magnuflux the size of a finger print. The second block, with core shift, had to be sleeved and they leaked when I pressure tested them. Third block had to be sonic tested before I did any machine work. Very expensive build.
That's what I'm a little afraid of Bert. All the early hemi engines I've bought so far were in very rough condition and had been sitting outside for long periods of time.
There are 3 different head gaskets for the Chrysler engines...what exactly is your combination of parts and which gaskets did you buy ?
The heads and block are both 1955. I bought the Fel-Pro kit FS7746PT. As much as I want to I'm not going to start disassembling the engine until I get the radiator pressure tester to see if I can tell exactly where the leak is but I've been second guessing everything I did when I assembled it. Could this be caused by the head gasket being installed upside down? I thought I installed them correctly but I just don't know what would cause such a fast leak.
I just went back and read the opening post. Let's assume the machine shop did an Ace job checking for cracks and related problems. They did address a pours issue in one place and make a repair. Sounds like a solid build from there. Any of the external bolts that can leak should not let water into the crankcase. Intake manifold, same thing. This kind of points the finger towards the Head Gaskets. If this in fact is where the issue is, while you're doing the water pressure test have the valve covers off and plugs out. If it is a head gasket the water shouldn't go direct to the pan, rather fill a cylinder with water and without and up and out the plug hole. If the water goes direct to the pan I would start looking for an overlooked freeze brake. I know there are different gaskets for different year motors. I don't remember all the cross overs but seems each gasket is marked either top or front. This can get you into trouble if they are Left and Right specific. I'm kind of doubting that is your issue being an uncovered water hole would let coolant just run through and into a cyl or?? Before totally tearing down the motor I'd lift the intake and remove the valley pan and inspect verry close the block behind the pushrods. That is a very thin casting with water jacket behind it. I have seen several blocks freeze cracked in that aria. It's very easy to overlook that space and being your motor sat outside for an extended period of years it should be inspected first.
P.S. If you're sure there was no white smoke (water vapor) coming out the exhaust while running you don't have water getting into the Cyl's.
No smoke of any kind. It was running great. No misses or strange noises. Just noticed a good bit of steam coming out of the breathers on the valve covers. I didn't know why but shut it down and happened to check the oil. I don't think it started leaking until it had been running at temp for a few minutes because the first time I started it and the exhaust manifold bolts were leaking a little I don't think it had started leaking in to the crankcase. I don't believe this would cause a problem but it seems like from what I've seen the original radiator caps for vehicles of that time were rated at 4-7 psi. I used a 16 psi cap because I read it made for a more efficient cooling system. This wouldn't be a problem would it?
I've held off commenting here because I am not familiar with the hemi construction, just wanted to follow up on the suggestions to pressurize the system and try to identify where the leak is. We used to do that with the diesel engines we worked on in the HD shops I worked at, and we'd pull the oil pan and inspect from underneath. Depending on how severe the leak is you may be able to identify where the water is coming from. It sure seems that a head gasket is you most likely failure point. Good luck!
I doubt the high-pressure cap caused any kind of leak. It may have helped push more water through the leak point, but it was going to be an issue anyway.
What does the oil look like? Does it look like oil, or chocolate milk? If you drain in the pan, does coolant come out first? I have had a little steam come out on startup on non PCV equipped engines. Condensation is a thing. It's coming out on PCV equipped engines, too, it just cannot be seen.
He said after running the fluid level went up about 2 quarts on his dip stick. That's a pretty significant water leak!
That's what I figured about the cap too. Probably helped push a lot more in but not the cause. The oil did look like chocolate milk. I have drained it and was actually going to try and measure how much actually came out to see for sure but it looked to me on the stick to probably be around two quarts higher.
Yikes! Ok, missed that, but then this is not head bolts, IMHO. I have only ever seen head bolts weep. If it is pushing that much coolant into the oil, I would tear it down. I know that this sucks. If I were closer, I would come over and help. The bearing shells might be wiped. They also might not be, but if you chance it and they are, you might be off to the crankshaft shop. This is most likely a bad head gasket. Head bolts and head gaskets are the only place on a first-generation Hemi where the oil and water get close, unless there is a defect in the iron. A pressure check with the pan and valve covers off will reveal that. Focus on three areas. See if coolant comes out up top, down the drains at the corners of the heads through the block, or the bottom of the lifter valley. Oil only normally goes up through the passage to the rocker shafts, and down through the head drains. I gave a good long stare at my extra heads, blocks, and gaskets. There are areas that I marked above that are of concern. The rocker arm oiling passage is right next to two cooling passages. If you flipped a head gasket on installation, you would have blocked the rocker oiling on that head (easy to see, there will be no oil under that valve cover). I am unsure what that would do with those two small cooling passages being blocked, but they are obviously there for a reason. The upper two arrows in the picture are the oil drain back holes. They are also adjacent to coolant passages, and to head bolts. Those, and the bolts, are where coolant can make it to water via a bad head gasket, unless up over and out the pushrod holes (seems unlikely). When you pressure test, if you see oil coming down a head drain back hole, pull and seal that adjacent head bolt, then repeat the pressure test. Yes, I know that the head gasket is blown either way, but that will tell you if it is the bolt threads that are causing the failure.
The pressure check with the valve covers off will also reveal if there is coolant bleed under the rocker towers, or above them, although I would find it hard to accept that this much coolant moved past machined metal-to-metal surfaces, under properly torqued head bolts.
Thank you very much for this info and the picture gimpyshotrods. This is very helpful. I'm fixing to go pull the valve covers and pan to smoke things over. My pressure tester is supposed to get here Wednesday. I wish I had paid more attention when I put the head gaskets on. They weren't marked in any way like Front or Top. I'll know soon enough if that is the culprit. Another thing I noticed was at 2,500 rpm the oil pressure was close to 90 psi. I am running the 340 high volume pump but this still seemed high. If I did install the head gasket incorrectly and the rocker oiling hole was blocked could this explain my leak and the high oil pressure? Sorry for the continuous questions but as this is my first build by myself I'm afraid I might be about to learn an expensive lesson. Thank y'all for all the help.
Keep the questions coming! This hobby lives or dies based on the sharing of knowledge! You have already reached a high bar for a solo build. A few bumps along the way are to be expected. Blocking that oil passage would cause higher oil pressure. It would be difficult to speculate as to how much higher, but it would be higher. It might have caused a head gasket leak, as that area where the flow is blocked would not have seen extreme pressure. I guess it could have blown through to the coolant passages, and then allowed coolant back in when the pressure dropped. It is all just speculation, though. Pull the valve covers and you will know for sure. If there was assembly lube on the rockers, you might be ok up there. Bearing shells and gaskets are not free, but they are cheaper than a bunch more machine work. Hemi head gaskets are asymmetric, but there are a few key features to watch out for: Three passages on one side. just one on the other. The holes for the pushrods are also asymmetric, but often will fit the wrong way. Observe how they are staggered, and make sure that the stagger in the gasket matches the stagger of the pushrod holes. You can see the ghosting of a head gasket on this head. This is not a good example, though, as the pushrod hole closest to the combustion chamber appears to have a gasket hole that is staggered the wrong way. The Hemi book has a better picture, but gaskets vary: The dual cooling passages arranged next to the rocker oil feed hole is the critical focus here.
Now that I look more closely, a flipped gasket might still allow oil flow to the rockers. It appears that what would be a coolant hole in the gasket would partially align with the oil hole. It might depend on the exact configuration of the gasket.
I poured up all the oil I drained and found out I seriously misjudged the amount of coolant that leaked just based on the dipstick. I poured in 6 quarts of the Joe Gibbs break in oil and I drained out a little over 6 and a half quarts so maybe it didn't run long enough to damage the bearings. I also pulled both valve covers. It looked a little dry and there was surface rust on the rocker stands from the condensation, but there was oil pooled up at the bottom of the head and the spark plug tube holes on both sides so I assume there was oil making its way to the valve train.
After pressurizing the coolant system to 15 psi and letting it sit for ten minutes I only lost 1 psi. It was pushing coolant out of the top three valve cover studs on both sides. Unfortunately I still haven't been able to get back down the shop to start resealing all my bolts with the Loctite 545. I'm hoping to get back on it tomorrow. After pouring up all the drained oil and finding out I had seriously misjudged the amount of coolant in the oil, maybe I'll get lucky and it'll just be from some leaking bolts.
Radiators and heater cores can only withstand 15-30 psi before they fail. If you cap off all cooling hoses going to the engine with PVC plumbing caps, you can inject shop air through a tire valve mounted in one of the caps and go to a much higher pressure than your radiator can withstand. Remember to double-clamp the caps, then ziptie a shop rag over the cap so if it manages to come loose it won't hurt you. Sometimes to find a leak much greater pressure is needed than what a radiator pressure tester can safely provide. It might be wise to bottle up your used oil in some clear plastic jugs, then put them in the freezer to make sure what separates out is water or antifreeze. Reason I bring this up is years ago I pulled the dipstick to check the oil on my daily driver and thought I saw the dreaded "oil milkshake". It turned out the PCV valve was defective, drawing humid air into the crankcase where, after the engine was shut down, the water vapor condensed and was mixed with the oil.
The Jalopy Journal
