I am sure it has been discussed before, but I thought I would get the latest information. I will be pulling the heads on my 48 Merc Flathead soon to do a valve job. What are the best head gaskets to use with Aluminum Heads. Also best practices for install. Thanks in advance.
Hey Ron, Share the info with the rest of us. I am in the same boat and could use some advice on the best head gasket to use with aluminum heads.
Like Ole Don wrote Best Gasket brand gaskets. If the heads are flat use their copper gaskets to help sealing spray both sides of the gasket with dull aluminum or silver spray paint three light coats per side this works for me every time. Be careful on torque those old threads don't like to be pulled to much if your using head bolts. On Aluminum heads I go to 55 foot pounds doing it in three steps 26 then 40 then 55 foot pounds following the Ford torque pattern. After the first fire up of the motor when everything has cooled check the torque again you might find a little movement before reaching the torque setting but this is normal. Even in my gas blown flathead I run in my lakester I seal the copper gaskets the same way so far its worked at 170 plus MPH.
I just did this for the first time, here are some things I learned: If you go with studs, studs are not all equal length. Dry fit them first and see how they fit. NO ONE tells you this. Best gaskets are good. DEFINITELY retorque after the first heat cycle or else risk overheating and/or boiling over. Use Permetex #2, it is very forgiving. That said, I still have some weeping studs as I ignored recommendations for copper spray. The leaks aren't bad, but definitely annoying. Your mileage may vary.
I spray permatex copper coat on the gasket and on bolts or studs I use GM Pipe sealant with PTFE part # 12346004 avail at GM dealers, the best sealer I have ever used. It does not harden and I re-torque at least three times or until the torque remains constant. I also apply anti sieze to the shaft of the bolt or stud to help removal later.
With flat heads and deck surface there should be no need for any sealers on the gasket. Studs or bolts should be sealed with a good grade of plumbers pipe dope. Not spraying the gasket with some kind of sealer has nothing to do with weeping studs.
Copper gaskets will cause an electrical current to be generated with aluminum heads. The heads will corrode very quickly but the block will have no rust in it. Beware!!! Copper spray with the graphite gaskets will permently glue the heads to the block. Just use the graphite gaskets with no spray.
ask 10 guys...get 10 different answers. There is no fool-proof way...do what works for you. Personally, I have copper gaskets under aluminum heads, running 6psi. of boost with a 471 blower. I have a 7psi Radiator cap. No leaks, no seeping, no blow-outs. No sealant other than stud threads in the block. Sometimes things are truely trial and error.
After building well over 250 motors so far as well as being someone who actually uses them and who was taught by some of the best old timers around many years ago. Copper gaskets work the best PLUS you can reuse them. Oh boy reuse them that might start another bunch of posts!
http://www.shopengineparts.com/part...ype=Domestic+Auto&make=Ford&model=Flathead+V8 Cometic has their Multi Layer Gaskets available also. Coming out with Y block shortly too
I have nothing to gain from my post. I am reporting what happened to me. They were brand new heads and after 6 mo use, they were severly erroded around the water passages. Yes I had antifreeze and corrosion additives in the system.
Bob not only do I use solid copper gaskets on the ARDUNs I build I also use them on the supercharged flatheads I build. Sealing them all with dull aluminum or silver spary paint works perfectly everytime. May even help with that electrolist problem that I seem to not have.
I'm a big fan of spraying gaskets with aluminum paint. I've been doing this since almost 50 years & it's always served me well. Why did I start doing it that way? Because my dad did it too. Once I was old enough to spray paint, he had me spray all his gaskets. Not just head gaskets either. Threads were generally sealed with Permatex Aero. His engines never leaked. Nowadays I often use Teflon pipe dope & teflon tape instead of Permatex. But I still use the aluminum paint.
If you ground your radiator you will be surprised how much less corrosion you will have, course I have been only doing this for about 50 years now so I am kinda new to this stuff.
First of all - it will "never" stop being discussed . . . it is the nature of all things flat! I have used both 'Best' gaskets as well as the copper 'big bore' gaskets . . . and solid copper gaskets on blown motors. Here are a couple things that I've "learned" - and I'm always learning: 1) Flat is Good: There are no substitutions for flat block/deck surfaces and flat head surfaces. The single biggest problems that many face are that their gasket surfaces are either not flat, or compromised (corroded, etc). The second part of this . . . is . . . okay . . . they have a set of heads and they got a deal - from a buddy, eBay . . . or Uncle Festus had them in his barn - and they're old, abused, corroded and NOT flat. Okay - I said it . . . whupseeeee! 2) Gaskets are like Cell Phone carriers . . . for every brand one guy swears by, the next guy says they suck. Truth be told - they probably ALL work if the application/environment is correct. 3) Gasket Manufacturer's Recommendations: If nothing else, ASK their technical folks what they recommend - great place to start! Do they recommend sealant or not? What sealant? 4) Reputable Builders and Old Dogs: Every one of us will tell you a 'story' of what worked for us. You decide who to trust . . . and pick your poison. We will never ALL agree. 5) What Do I Do: I go back to 'Item #1' and pretty much square deck every block on every engine I build. I also do this to set the compression height on each bank - I measure with the crank, and I specify to the machine shop what it should be. It is never the same side-to-side. In the end, I have a brand new deck surface I can trust. Same with the heads - if they're new or old . . . I want to ensure they are flat to begin with. a) Gasket Prep: On street motors, I really don't believe you should need ANY gasket sealer on the gaskets - Hell, that is WHY you have gaskets . . . to seal the surfaces. You can use sealers, paint - whatever . . . all of it will work for somebody. I would probably use modern spray-on sealers - Copper Coat, Permatex . . . whatever. I do believe that spray on sealers are much easier to apply to a semi-consistent thickness (just can't do this with a dumb-ass brush . . . and I sure have tried!). b) Blown Motors: Okay - all bets are off . . .depends on boost. Below 10 lbs of boost, you can probably get by with just gaskets - no o-rings. But as boost goes up - problems show up. c) High Boost: Once you get over 10 lbs - sealing the deck becomes THE problem you'll be trying to solve. For high-boost, you'll probably need to CNC O-ring grooves in the block and the heads. You'll use .041 stainless o-rings, you'll have receiver grooves in the block , etc. d) Fantastic Gasket Sealer: The best sealer that I know is Hylomar spray cans - it never really hardens and the real purpose it NOT to seal the combustion chamber (no sealer will do that) - it is to seal the water jackets. I use the spray cans and spray a light coating on both sides of the gaskets before I install them. e) Stud Sealers: Regardless of ALL the crap above - you have a WET deck! That means that water is on the coarse threads of ALL the studs! This has nothing to do with your head gaskets - it is has everything to do with sealing the stud threads so they don't weep through the heads. I used to use the age-old Permatex 'Gorilla Snot' - but have recently changed to the liquid teflon style sealers (great stuff). I liberally coat the bottoms of all studs/bolts with this stuff - works great! Again - if you're leaking water around your studs/bolts - has NOTHING to do with your head gaskets! Also,the place to 'fix' the leak is NOT at the top of the stud/bolt - it is inside the block where the coarse threads are - use Teflon, it is your friend! Okay - enough of my endless babble . . . good luck with all things FLAT!
Yeah, my old radiator's not corroded, but it was bolted down solid. The Plymouth radiator has a flexy sheet metal angle frame each side, that bolts right to the car. It doesn't need grommets to avoid stress on the fragile core, and so it's well grounded. ...but I was definitely gonna rubber-mount the new $$$ aluminum hot-rod radiator, so thanks for the reminder Carl!
Is that because the crank's not at the exact intersection of the bore centerlines? I've never done heavy auto machine work, so never thought of that at all.
I use paint because the surfaces are never quite perfect enough from the typical machine shop. Your work clearly doesn't need it. 100% Teflon rocks. No question.
Are you still on this site. You’re one of the smartest guys on this topic, would like to dm you. Thanks.
I've used aluminum/silver paint on head gaskets (although not flatheads) for years. It does two things; one, the powdered aluminum pigment used helps with sealing and doesn't burn out or degrade from the heat. Two, if you pull the head the gasket usually will come off cleanly. I got turned on to it when using some shim-steel head gaskets (to raise compression) and had trouble with sealing. A old-timer told me to spray the gasket until it's thoroughly 'wet' then install, haven't had trouble with one since...
From time to time I get on the HAMB. I got a bit burned out on posting - just taking too much time out of my too busy dang life! Feel free to DM me - happy to help guys out. You can take any advice I give like going to the 'Fortune Teller' - keep what you want to believe, throw the rest the Hell out! LOL
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