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Technical 331 Hemi Coolant in Oil

Discussion in 'The Hokey Ass Message Board' started by MRW1994, Dec 31, 2021.

  1. MRW1994
    Joined: Dec 31, 2021
    Posts: 260

    MRW1994
    ALLIANCE MEMBER

    I need some help knowing where to start looking for the coolant leak I have on my freshly built 1955 331 Hemi. When I first started it the other day to break in the solid lifter cam it fired up, I went straight to 2,500 rpm and planned on running it there for twenty minutes. After about five minutes or so as it started to get warm I had to shut it down because the thread sealer I used on the exhaust manifold studs didn't work on some of them and it started boiling antifreeze off. I removed the studs and went back with bolts with better sealer. At this point I don't think it had been warm long enough to start leaking into the crankcase because all the coolant I drained out of the block filled the radiator back up to where it was when I first filled it. I started it again yesterday, went back up to 2,500 rpm and let it come up to temp. After about ten minutes of it running very good I noticed a good bit of steam and water vapor coming out of the breathers on the valve covers and shut it down to check out what was going on. This is when I found at least two quarts of coolant had made its way to the crankcase. The engine ran great and there was no white smoke.

    I'm not sure if the Fel-Pro head gasket is correct for my application or if I should have went with another kind like a copper gasket. The block was also in pretty rough shape from sitting outside for a long time before I bought it. The machine shop sleeved one cylinder and also drilled and tapped a hole in the bottom of the block where there was some pitting into the water jacket. It is a 3/8" pipe plug about 1/8" from the side of one of the cylinders. The work was done at a reputable machine shop but anything can happen I guess. The heads and block have both been magnafluxed. For reference on my head gasket question the static compression ratio is 10:1 and I was running a 16 psi radiator cap.

    Would the head gasket be the first place to start or any other thing I might have overlooked while I was assembling the engine? I've built other engines with my dad throughout the years but this is the first one by myself and my first hemi. I've learned a lot from the members of this forum and any advice y'all can give me will be much appreciated. 331HemiStand1.jpg
     
  2. Bandit Billy
    Joined: Sep 16, 2014
    Posts: 12,287

    Bandit Billy
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    I hope you are running straight water on start up. I learned an expensive lesson once doing a start up with antifreeze in the system.
     
    fauj, mad mikey and HemiDeuce like this.
  3. MRW1994
    Joined: Dec 31, 2021
    Posts: 260

    MRW1994
    ALLIANCE MEMBER

    No I wasn't aware of that. With the temperatures around here changing so quick I ran antifreeze just so I wouldn't have to drain it.
     
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  4. Bandit Billy
    Joined: Sep 16, 2014
    Posts: 12,287

    Bandit Billy
    ALLIANCE MEMBER

    I don't have a lot of experience with hemis, actually I'm a noob. I know I had to seal most all of the exhaust bolts and a couple of the front cover bolts as it seems everything reaches the water jacket on these things. I'd be questioning the head gaskets, I can't imagine what else would put that much coolant in the pan so quick. @Pist-n-Broke loves these damn things, maybe he has a better idea.
     
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  5. I love early hemis but I need more pictures of the swept side in the background.
     
    stillrunners likes this.
  6. MRW,
    Where in middle Tennessee,,,,you might be close to me .
    Your engine looks good,,,,,and the truck sitting behind it as well .

    Tommy
     
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  7. foolthrottle
    Joined: Oct 14, 2005
    Posts: 1,402

    foolthrottle
    Member

    What bolts, studs are you using for the valve covers? I've had coolant leaks there in the past
     
  8. MRW1994
    Joined: Dec 31, 2021
    Posts: 260

    MRW1994
    ALLIANCE MEMBER

    Billy, yeah I sealed all the bolts but I'm finding out that the Permatex thread sealant I used didn't work so well so I've been going back with RTV. I'm hoping for it being the head gasket being my leak and not somewhere in the block.

    Thanks Tommy I'm in Franklin, TN so a little ways but not too bad.

    Foolthrottle, I also noticed before I shut down the last time that I was going to have to reseal the top three valve cover studs as they were leaking as well.

    57 Fargo here's a few pictures of the Sweptside this hemi will be going in. I really like your 57 Fargo as well. 1958DodgeSweptside.jpg 1958DodgeSweptside1.jpg
     
  9. Thats a good looking truck ! You dont see them to often..
    If you ask me This is the last body Dodge that looked good !
     
    SS327 likes this.
  10. If you want to be safe, pull the pan and check all the bearings. Sometimes anti freeze destroys stuff. The composition head gaskets are better than solid copper for street use. Copper was used because the higher temps burnt out the layers in comp gaskets. The comps are more forgiving if you have any surface irregularities.
     
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  11. Man I want a sweptside bad…
     
    fauj, gimpyshotrods and Desoto291Hemi like this.
  12. Also,,,,there is a place that never gets checked on a Hemi block .
    The oil return cavities in the ends of the block for oil drain back .
    Believe it or not,,,,these can leak coolant as well .
    Some are very thin from core shift,,,,,or just a casting defect ,,,,,,and can be porous .
    They can be safely fixed though,,,,,and never leak again .
    I’m willing to think it might be your plug that was at the base of the cylinder.

    Or,,,,,,if you get lucky,,,it’s just a head gasket,,,,I hope so .
    Either way,,,it sounds like some in depth attention to find the problem .

    Tommy
     
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  13. MRW1994
    Joined: Dec 31, 2021
    Posts: 260

    MRW1994
    ALLIANCE MEMBER

    It does sound like I for sure should do a full tear down to make sure everything's alright. Next time I'll be sure to run straight water for break in until I'm sure everything's sealed up. If the antifreeze did cause damage to the bearings will that be in the way of visible galling? It didn't seem to start leaking coolant until it had been at operating temp for a few minutes.

    Also I think I read somewhere, probably here, that the BEST brand head gaskets are good. I'm not sure if it will end up being the head gasket or something else but maybe they're better than the Fel-Pro.
     
    turboroadster likes this.
  14. One thing for sure,,,it looks like a fine build,,,,,very clean looking .
    Maybe you will get lucky,,,I hope you do .

    Tommy
     
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  15. junkman8888
    Joined: Jan 28, 2009
    Posts: 1,035

    junkman8888
    Member

    The easiest, quickest, and most assured way of finding where your engine is leaking antifreeze is to restrain yourself from disassembling the engine until you do this; cap off any water hoses that go to the engine with appropriately sized PVC plumbing plugs and hose clamps, on one of those plugs you need to drill a hole in the center of the cap and install a tire valve so compressed air can be pumped into the coolant passages. Remove the pan, the valve covers and the spark plugs, then pump in some air and listen. If you can't pinpoint the leak mix up a spray bottle of tap water and dishwashing soap, spray on the area where you think the leak is and look for bubbles. I wish you luck.
     
  16. MRW1994
    Joined: Dec 31, 2021
    Posts: 260

    MRW1994
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    Thank you Tommy.

    junkman8888 I will definitely do that first. That was why I came here to ask before disassembling. It seems like if it's not the head gasket it would be very difficult to pinpoint once its apart.
     
  17. saltracer219
    Joined: Sep 23, 2006
    Posts: 1,071

    saltracer219
    Member

    That will work but since you are already on the stand I would suggest pulling the valve covers and oil pan and pressurize the cooling system with a radiator pressure tester and look for the coolant leak.
     
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  18. MRW1994
    Joined: Dec 31, 2021
    Posts: 260

    MRW1994
    ALLIANCE MEMBER

    That's a good idea too saltracer. I'll start there and if I just cant pinpoint the leak with it on the run stand I'll put it back on the engine stand and do like what junkman suggested.
     
  19. tubman
    Joined: May 16, 2007
    Posts: 6,916

    tubman
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    Here's something off the wall. Do you have an aftermarket front cover and water pump on it? I installed these on my '54 Hemi and when I fired it up, it leaked anti-freeze into the oil because I used the wrong water pump gaskets. I caught it right away and cleaned everything up before any damage was done.

    Probably not the problem, but I thought I'd throw it out there.
     
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  20. MRW1994
    Joined: Dec 31, 2021
    Posts: 260

    MRW1994
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    I'm running a stock timing cover with a rebuilt 392 water pump. I'm hoping mine is like yours and didn't cause any damage. It didn't run for very long like that and I never heard anything weird. It had high zinc break in oil in it so hopefully that helped protect the bearings.
     
  21. jaracer
    Joined: Oct 4, 2008
    Posts: 2,419

    jaracer
    Member

    My thoughts exactly except I'd use a radiator pressure tester.
     
  22. gimpyshotrods
    Joined: May 20, 2009
    Posts: 23,264

    gimpyshotrods
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    I have never had any luck sealing bolts with RTV.

    I go through about 4-bottles of Loctite 542 and Loctite 545 in the shop per month.

    We used 545 in the test labs at General Motors. It holds up to coolant and temperature just fine.

    542 has thread locking properties, which makes it good for things that vibrate.
     
  23. RTV is just plain a dirty word to me. Not bad for a get me home Band-aid but there are several products out there targeted for wet bolt sealants. Loctite 545 is but one of them. Life is a learning curve we never get all the way around. All new motors should have straight Water on first start up (or no water). If you have one, a hand pump test to make sure the cooling system is sealed. Hemi's are grate motors when things are right and a special Pain In the Ass when they are not. It pays to know those that know.
     
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  24. Glenn Thoreson
    Joined: Aug 13, 2010
    Posts: 928

    Glenn Thoreson
    Member
    from SW Wyoming

    When it was rebuilt did the mill the heads for flatness? I use Best gaskets and never had a problem. Copper gaskets are very unforgiving if surfaces are not perfect. Did you tighten the head bolts in the proper order? Very important. Anti Freeze is one of the best leak detectors out there. It will leak out of places that water won't. For thread sealer I use Teflon pipe dope. It works really well and is readily available at a hardware store. Don't use Teflon tape or RTV. Two of the most misused products out there. Try to get as much water/oil mix out of there as you can before you button it up. Good luck.
     
  25. MRW1994
    Joined: Dec 31, 2021
    Posts: 260

    MRW1994
    ALLIANCE MEMBER

    I'll make sure to go back with the good Loctite thread sealer. After the Permatex thread sealer I used on all the bolts started leaking in different places I became frustrated and used RTV to try to get a solid run out of it. The block was decked and the heads were milled. I also tightened the head bolts in sequence with what the Chilton's book called for so I'm not sure why it would be the head gasket but I'm still hoping that's what it ends up being.
     
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  26. MRW1994
    Joined: Dec 31, 2021
    Posts: 260

    MRW1994
    ALLIANCE MEMBER

    On a side note about sealing up all the bolts on the early Hemi engines I was wondering the other day how did they used to keep all those bolts from leaking in the 50's with almost every bolt being exposed to oil or the water jacket?
     
  27. Truckedup
    Joined: Jul 25, 2006
    Posts: 4,661

    Truckedup
    Member

    The sticky brown Permatex in the bottle with the brush in the cap..
     
  28. If you ever got to take a virgin motor apart, you found out the factory had its own thread sealant and use it on near everything. Now that you have poor product in most of the threaded holes, I would advise cleaning them all with proper taps to get the RTV out and a good quality carb type spray to flush the permatex. Use a shop vac to help evacuate the RTV. To get a good seal with any advisable product both the tapped threads and bolt threads must be clean. I understand your frustration, your not the first guy to do this.
     
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  29. dwollam
    Joined: Oct 22, 2012
    Posts: 2,322

    dwollam
    Member

    Did you check the dowel height on the heads to block? If deck AND heads milled, those dowels may be too tall and not letting the head go all the way down. That would make a big gasket leak. I used Best brand gaskets on my 331 and they sealed great. They are also quite thick.

    Dave
     
  30. Lots of things to check. First order of business would be pressurize system to determine the area or areas where the leak is coming from.
     

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