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Flathead head sealing

Discussion in 'The Hokey Ass Message Board' started by 26 FlatRod, Feb 13, 2009.

  1. Flat Ernie
    Joined: Jun 5, 2002
    Posts: 8,406

    Flat Ernie
    Tech Editor

    ARP sell a special hardened bevel washer which you can fit a viton o-ring underneath - will eliminate all the leaks. Did this on the last one with some older Edmunds heads that had some corrosion around the studs - no problems. No leaks.

    I will second the 515 sealant (also 518) - be forewarned, they are expensive, but you won't find their equal.
     
  2. JohnEvans
    Joined: Apr 13, 2008
    Posts: 4,883

    JohnEvans
    Member
    from Phoenix AZ

    Why not run it DRY?? Maybe for 30 seconds or so to see if it will run . But not long enough to get the entire engine warm/hot. Flatheads espicaly have hot spots that will get real hot real fast long before anything else engine wise. Think exhaust ports for starters. There is something odd about this whole prob., are the heads new or used?
     
  3. This sounds like a disclaimer. We all should know that an engine can be run dry, but not for extended periods of time. On the drag strip this is done often in some classes.

    As to your problem; Anyone out there like the Graphtite gaskets? Sounds like the favorite method involves a spray, and that's not to be done with a graphite type gasket, as it is designed to allow movement between the two different metals.

    I have never built a flatty, but have used shim gaskets and coppper coat, started/warmed up dry(gradually mind you), even Perma-Torque gaskets are recommended to be warmed up dry.
     
  4. 26 FlatRod
    Joined: Sep 22, 2004
    Posts: 167

    26 FlatRod
    Member

    I agree, there must be something we are missing. Other than sealing the studs I did not think it was supposed to be that difficult to seal up a flathead.

    I have brand new Edelbrock aluminum heads and I looked at them pretty close before I put them on. Also the deck was trued up and I am using new gaskets and new studs. I don't get it. I would not call myself an expert, but I have built and helped build several engines over the years and I am aware that getting the head gasket to seal and torquing (and re-torquing the heads is a big deal so I thought I was paying close attention to all the details.

    The next time the head comes off I am going to re-check all sorts of things, But I think as long as both surfaces are flat and all the holes line up it shouldn't matter if it is aluminum or steel.

    -Dave
     
  5. 26 FlatRod
    Joined: Sep 22, 2004
    Posts: 167

    26 FlatRod
    Member

    The more opinions I hear, the more I think that the installation sheet that Speedway gave me has some good pointers. Here is what they wanted me to do:

    - Use Moroso ceramic seal on all the threads (this is a block sealer)
    - Spray both sides of the head gasket with aluminum paint and put it on before it is dry.
    - Torque the heads down from left to right instead of the normal torque pattern that they show in virtually every book and manual. ( they acknowledged that this is different)
    - DO NOT fill the system with water
    - Start the engine dry and run it until you cannot hold your hand on the head. Let cool and re-torque. Do this about 3-4 times.
    - Heads and studs should be sealed now. Fill it with coolant.

    I did not agree with the torquing method, running it dry or using aluminum paint for a sealant so I just did not do those parts. Are they crazy? or do they some good ideas here.

    -Dave
     
  6. rat deuce
    Joined: Feb 7, 2007
    Posts: 189

    rat deuce
    Member

    Ten studs per side, sounds like nuts are bottoming out before the head is really tight to the block.....
     
  7. stick1955
    Joined: Apr 5, 2007
    Posts: 27

    stick1955
    Member

    i had a guy once resurface my heads with a fast cut.the surface was as rough as a brand new pair of levis.you could feel the grain with a screw driver handle.it took 3 sets of gaskets and many nights in barn before a machine shop guy came over to lend a hand.it took him 3 seconds to identify the problem.the gaskets cant seal problems i can guarantee that will never happen again.slow cut the head fixed it!!!!
     
  8. R Pope
    Joined: Jan 23, 2006
    Posts: 3,309

    R Pope
    Member

    We always used thick aluminum paint on head gaskets on flatties, worked great. Some seepage was looked at as being normal, it stopped in a few hundred miles.
     
  9. 26 FlatRod
    Joined: Sep 22, 2004
    Posts: 167

    26 FlatRod
    Member

    I guarantee that is not happening. The 10 studs are the lowest ones on the head ( all the short ones). I turned the studs in till it touched the shoulder, then backed it off 1/4 turn. The shoulder is only about 1/2" and the head is about 2" thick in that area.

    -Dave
     
  10. Flat Roy
    Joined: Nov 23, 2007
    Posts: 533

    Flat Roy
    Member

    Some of my buddies that build BIG race motors and Even bigger diesel motors recomended that I use a product called Irontight in the coolant. It worked great.
     
  11. Flat Roy
    Joined: Nov 23, 2007
    Posts: 533

    Flat Roy
    Member

    I used a product, recommended by my diesel engine builder buddy, called Iron tight. I run a 16 lb. When I first started it it leaked for acouple of minutes and not a drop since.
     
  12. Flat Roy
    Joined: Nov 23, 2007
    Posts: 533

    Flat Roy
    Member

    I guess I screwed this up a bit!!!
     
  13. hombres ruin
    Joined: Nov 21, 2006
    Posts: 3,314

    hombres ruin
    Member

    I am running an 8BA flathead,with offy heads and copper gaskets with coppercoat,i used bolts and washers and i torqued them according to the correct sequence,never had i had a leak around the bolts and i drive that thing always,i dont like the graphite gaskets,i think copper gives you a great seal.
     
  14. Jimmy2car
    Joined: Nov 26, 2003
    Posts: 1,707

    Jimmy2car
    Member
    from No. Cal

    26 Flatrod
    If I understood what you last posted, you have installed the studs wrong. Each stud must be clean, as well as the holes in the block. Then, one at a time, apply sealant (I use Permatex #2) to each stud, install till it stops, then tighten to 5-8 ft lbs. Next, clean all excees sealant from the deck surfaces. Install head gaskets with sealer (I use Hylomar), install heads, washers, nuts and begin torque sequence of your choice starting at 20#, then 30#, then 45#, then finish at 50# with the Aluminum heads. Wait awhile, then retorque. Retorque means: Back off nut a bit, then go to final torque setting again. Do this 3 or 4 times until torque begins to stabilize. Add water, start engine and check for leaks. Retorque again after some heat cycling. Always retorque aluminum heads COLD
    Good luck
    Jim
     
  15. man-a-fre
    Joined: Apr 13, 2005
    Posts: 1,311

    man-a-fre
    Member

  16. Flathead Phil
    Joined: Jan 12, 2006
    Posts: 37

    Flathead Phil
    Member
    from Australia

    I have had simillar problems with Flatheads. We have some stuff down here called Holden stud sealer and is made by Holden Motors a Part of GM USA. You will remember them as they made the new Pontiac GTO. This stuff is well recomended by car guys. Its has a funny smell and reminds me of some floor tile glues. I have used it on old bolts and new bolts and seals them every time plus I just paint the head caskets with alluminum paint like my father taught me as a kid . I have tried not sealing the threads and found its trouble. Check out your GM dealer and they may have it or can get it in.
     
  17. 26 FlatRod
    Joined: Sep 22, 2004
    Posts: 167

    26 FlatRod
    Member

    I did everything like you said above except:

    I did not torque the studs for 2 reasons. When they hit the "shoulder" many of them will cock at a slight angle, this makes it very difficult to get the gasket or head in place without damaging something. The other reason is that when they cock, that means all the threads in the block are not all in full contact which might create problems when you torque the heads down.

    I did not use sealant on the gaskets because I was told it was not needed on graphtite gaskets. I plan to use sealant next time. I noticed that Hylomar racing formula is the only one that lists head gaskets as an application. Is this the stuff you use and do you just apply it around the water passages?

    I did not back the nut off when re-torquing. why is this done?

    I know you said to retorque when the heads are cold, but I notice that the nut torque is lower when the engine is hot and I assumed they should be torqued to maintain the 50 ft/lbs. Is this going to mess up something?

    -Dave
     
  18. Jimmy2car
    Joined: Nov 26, 2003
    Posts: 1,707

    Jimmy2car
    Member
    from No. Cal

    Hi Dave, PM sent
     
  19. TraderJack
    Joined: Apr 10, 2008
    Posts: 330

    TraderJack
    Member

    IN all of the years I had flatheads I have never had a stud or bolt leak and that is beyond my comprehension. I do wonder why you say the studs cocked when you installed them to the shoulder!
    It would seem to indicate , to me , at least, that the threads are mismatched, either the threads in the block are too deep , or the studs too small
    Visualise a nut on a bolt, Do you expect the nut to wobble on the bolt?

    One solution would be to turn some new studs on the lathe to fit the stud holes tighter, or make new bolts larger.


    traderjack
     
  20. J'st Wandering
    Joined: Jan 28, 2004
    Posts: 1,772

    J'st Wandering
    Member

    The studs should be tighter in the holes than it seems they are. When I have put helicoils in cast iron I have a problem in not getting them to be as tight to the bolt as I would like. Could it be possible that there are a bunch of helicoils in the block?

    Neal
     
  21. 26 FlatRod
    Joined: Sep 22, 2004
    Posts: 167

    26 FlatRod
    Member

    I do not know what you mean by mismatched. The threads are the same dia and pitch I do know that. Also on std threads, there is always some clearance so there will always be some wobble. Class 3 threads have less clearance than class 1 threads but they all have clearance. so yes, I would expect the nut to wobble on the bolt.

    As far as tightening down to the shoulder, The "shoulder" on my studs is more like an unthreaded section not a real shoulder. Unless you have a real shoulder (or a thread undercut) the stud will cock slightly when tightened down.

    Making new studs is definatly an option if I have no other options. but this would be very expensive or time consuming. I think many other people have built flatheads without custom made studs.

    In the end I do not believe my studs are leaking anyway. I used ARP stud sealer on all studs and it started leaking right away. I think there is a problem with the gaskets or how I am installing them.
     
  22. 26 FlatRod
    Joined: Sep 22, 2004
    Posts: 167

    26 FlatRod
    Member

    There are no helicoils in the block. However, the threads may have been cleaned out with a standard tap when the block was being prepared
     
  23. A Chopped Coupe
    Joined: Mar 2, 2004
    Posts: 1,133

    A Chopped Coupe
    Member

    Just a question, what kind of studs are you using????????????
    Are they stock, ARP or ????????????????
    You mentioned a "shoulder" on the studs...........what shoulder. Also, the studs should never
    "cock" in the threaded holes unless they are bottoming out and the threads are shot.
    I have used this trick tought to me by a the late Rod Furtado; when using studs, use the ARP beveled washer part #400-8539 along with a Viton O ring (Viton is good for around 300 degrees C which is 572F). The bevel goes toward the head and of course the O ring goes between the head and the beveled washer. As you torque the nut, the O ring seals between the washer and stud................no water leakage.
    But it sounds like you have other issues....................
     

    Attached Files:

  24. 26 FlatRod
    Joined: Sep 22, 2004
    Posts: 167

    26 FlatRod
    Member

    I am using the stud kit from Speedway motors. I Know these are not the best money can buy, but I am not building a race motor and didn't think it was that critical when I bought them.

    When I say shoulder, I just mean the unthreaded portion in the middle of the stud.

    I have heard several other people on this subject mention that their studs would cock a little if you tightened them down all the way, and they recommended backing them off a bit(so it does happen). I think if the coarse threads are just rolled on to the shaft without any attention paid to the transition to the unthreaded section they may cock where the thread runs out. Now if the thread is properly relieved there and there is a nice chamfer on the block and the stud, then it would work great. I do not think mine are designed that way.

    Couple questions for you. If the head gasket is sealed properly, why are these special beveled washers needed in the first place. No coolant should even be getting up in that area. Next question is where is the o-ring sealing? I would assume it would have to seal on the unthreaded portion of the stud for it to seal correctly. I say this because if it was on the threaded portion it couldn't seal at all unless it was squeezed all the way down to the root of the thread. If it didn't, the coolant would just follow the root of the thread all the way to the top of the nut.
     
  25. A Chopped Coupe
    Joined: Mar 2, 2004
    Posts: 1,133

    A Chopped Coupe
    Member

    First off, a stud should never, never, repeat never be tightened down or torqued down.
    Whenever you put a stud in run it all the way down and then bring it out at least half to one complete turn.

    Second, the head gasket was never designed to seal the water from migrating up/around the threads of the stud/head bolt, it is only susposed to seal the block surface and the head surface so no water gets outside that area. If you look at old used aluminum heads you will most likely see the aluminum eaten away around the stud/bolt area, and in most cases even eaten out beyound the gasket sealing surface. Now with that said, that is why you always use a water type sealant like Permatex #2 on the threads, because unless the threads of the stud/block are brand new they will not be watertight, even brand new I'm not sure they would be watertight.

    What the beveled washers and Viton O ring do is to make sure there will be no water leakage up beyond the top flat surface of the head past the stud/bolt.
    OK, the O ring seals around the stud and is compressed by the beveled washer because the O ring is slightly larger that the bevel, so when it is torqued down it creates a seal around the stud at the head, and the washer maintains this crush.

    I know some people think it doesn't make any difference when it comes to buying fasteners and ARP is quite a bit more expensive than SpeedWay, but when it comes to fasteners you should always buy the best you can afford. I just took the ARP stud I showed earlier and put it in one of my cleaned flathead blocks............the one in the picture below. I could not rock the stud. On the other block I am currently building, yes I could rock it but not very much................hence the reason for using the beveled washers with Viton O rings, plus my heads are 6061 alloy and are much stronger aluminum than normal Edelbrock/Offenhauser, and because I will be running a blower they will be torqued to 65lbft.....................and will seal the first time.

    I am certainly not as knowledgeable as some of the people on this site when it comes to
    flatheads, but I do know what works for me....................

    IMHO
     

    Attached Files:

  26. TraderJack
    Joined: Apr 10, 2008
    Posts: 330

    TraderJack
    Member

    OK, modernizing the situation. Go down to the hardware store and by some pipe tape that is used on the plumbing. Wrap the studs with that stuff and screw them down tight!

    The teflon seals the thread against leaks for up to 150* water pressure in plumbing, so it should solve your problem.

    I always put the studs in tight to allow the removal of the head nuts when it came time to pull the heads. If you put them in loose,and you have a head nut sieze for some reason you will pull the stud.

    Which, of course, is the reason I finally when to head bolts! That solves all of the problems.

    traderjack
     
  27. Flat Ernie
    Joined: Jun 5, 2002
    Posts: 8,406

    Flat Ernie
    Tech Editor

    Teflon is meant for use on NPT which seal based on the thread itself.

    It will not work in this situation and as has been mentioned several times already, you should never tighten studs all the way down.

    I don't see why this is a problem though...


    I have also used the ARP beveled washers and viton o-rings. When I had to pull a head, the o-rings were sealed in and around the threads & I used a dental pick to get them out. Sealed well - no leaks.

    I've also used just Permatex #2 with no problems sealing. I don't trust any of the other stud sealers as most seem to be intended to seal against oil, not water.


    The way I see it, you've got two options. Re-seal your studs with something else, or run it as-is and put water glass in your cooling system.

    I seriously doubt there's anything wrong with your gaskets.
     
  28. A Chopped Coupe
    Joined: Mar 2, 2004
    Posts: 1,133

    A Chopped Coupe
    Member

    Studs are/where designed to be loaded and stretch in the vertical axis only and allows for a more precise control of torque due to the fine thread of the nut. When you tighten a stud down till it is tight/and or bottomed out it now acts like a bolt and is stressed not only in the vertical axis but is twisted in the horizontal axis also.................in which case you might as well buy a bolt because it is cheaper and also a stud is not designed for the horizontal load or twist.

    Certainly one of the drawbacks of studs on flathead motors is when you are trying to take the head off without removing all or most of the studs because the head will get cocked against the studs because they are not in perfect alignment. Also if you don't put antisieze and the shank of the stud it could become part of the head and I have heard of people having to cut the heads off.

    Studs are more of a pain, but for me the plus's outwiegh the negatives.

    IMHO
     
  29. 26 FlatRod
    Joined: Sep 22, 2004
    Posts: 167

    26 FlatRod
    Member

     
  30. A Chopped Coupe
    Joined: Mar 2, 2004
    Posts: 1,133

    A Chopped Coupe
    Member

    Just one comment about the ARP white sealant for studs that go into water. I used to use this sealant on SBC.........................and they would always leak, not a lot but some.
    I changed to #2 Permatex and never had any other problems. The #2 Permatex is the best,
    at least in my opinion. Get rid of the ARP stuff, clean it off really good, and swith to Permatex.


    IMHO
     

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