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Welding Aluminum Heads

Discussion in '"Stock" Alpine' started by Eleven, Jan 10, 2020.

  1. Eleven

    Eleven Gold Level Sponsor

    I have been trying to source coolant leaking between the block and the head on my SV. I recently had the head rebuilt as there was a hole blown in #1 by the exhaust valve. Head was R&R's and planed flat, etc. With the help of some good SAOCA club members I think I have narrowed it down to corrosion around the cooling ports. When I had it decked I think it made the holes wider and the ragged edges went outside of the head gasket ridges allowing coolant to work out. The hole was welded but to save this head it will need those ports built back up.
    So, here is my question: I know that weld material and cast parts have different porosity and will expand at different rates potentially causing cracking. A friend of mine had a weld done on his race car (not Alpine) and suffered a catastrophic blow up at 185 at Road America (CanAm car). I doubt I can get it up to that speed but can see the head being cracked.
    What are SAOCA Members experience with this? I am reluctant to do this and may just replace the head.
  2. Gordon Holsinger

    Gordon Holsinger Diamond Level Sponsor

    I can’t tell you about welding the head. But there is a problem with corrosion. Many of our cars have had poorly maintained over the years by past owners garages and so forth. One thing is to use distilled water not tap water and a proper coolant designed for aluminum, and change it yearly. Good luck.
  3. spmdr

    spmdr Donation Time

    Through the decades, I have had several heads welded, mostly by Tom Duncan at Parks welding.

    Tom uses 5356 rod and pre -heats the head.

    For the most part, no problems.

    This last head I was fighting had been welded several times and I think the main problem was not getting ALL the corrosion out of the weld site.

    Of course, the bigger the problem the less head you have after removing the corrosion.

    And the desire to SAVE as much of the head as possible has tripped me up!

    But I have learned the lesson a few times over, if you leave corrosion, you can expect more problems!

    Also, in general, early heads tend to be harder to weld because the metal is not as pure as later heads.

    I'm sure Smitty in San Diego could shed more light on the subject...

    Last edited: Jan 10, 2020
  4. spmdr

    spmdr Donation Time

    Yes, prevention is everything!

    On a street car, you have little excuse.

    We, in the vintage Racing world have more of a challenge.

    Antifreeze is more than NOT welcome at the Race tracks!

    I have not found a non-antifreeze that works worth a damn for corrosion protection.

  5. alpine_64

    alpine_64 Donation Time

    Dan do you store the cars with antifreeze in the system and then flush and replace with deironised water as part of the weekemd prep?
  6. spmdr

    spmdr Donation Time

    Funny you asked about that...

    Truth be told, ....do as I say not as I do!

    ...OR DID!

    After fighting a coolant leak/corrosion issue with the Weekend Racer head, I have a NEW appreciation of PREVENTION!

    As a matter of FACT, I DID drain the antifreeze out to take it to the track and put it BACK in after the last Track session!

    There was a time I was not as concerned with corrosion.

    But after having Alpine head cooling passages corrode closed, during storage I began to see the error of my ways!

    BTW, I have LONG given up attempting to recreate the banana shaped co0ling passage, after welding it up.

    I have resorted to just drilling holes to match the holes in the block.

    Of course, these smaller holes are more subject to being corroded closed.

    The other side of the coin is there is more Aluminum to corroded away before it causes a problem...

    BUT IF you KEEP the corrosion from happening in the first place, you are WAY ahead of the game(s).

    Now, excuse me while I go and Brush my TEETH! :)

  7. Eleven

    Eleven Gold Level Sponsor

    Good information and thank you! Any downside to going with an iron head other than weight?
  8. alpine_64

    alpine_64 Donation Time

    The iron heads have smaller valves, different manifolds, cams, distributor drive, different combustion chamber shapes... In theory could sort all of that...but still a heavier head.. Which is not good for a racer
  9. Eleven

    Eleven Gold Level Sponsor

    Thanks Michael.. Just thought I would ask.
  10. jumpinjan

    jumpinjan Gold Level Sponsor

    The cracked block repair shops (including aluminum head welding) are all gone around Ohio. A great shop here in Dayton was called Dayton Cracked Block. They did some wonderful repair work....and now gone!
  11. 65beam

    65beam Bronze Level Sponsor

    There were a lot of shops in the Dayton area that specialized in various jobs. I guess the shops that could set up a rear end are now closed. Brad is looking for someone to set up the rear end for his race car. You know of someone?
  12. jumpinjan

    jumpinjan Gold Level Sponsor

    I told Brad that he needs a LSD spool for racing and not just a "locked" differential that he borrowed (just welded spider gears). And to do that, I would look for a complete & different rear axle assembly. The Alpine axles just break too much too and only three ratios available.
  13. DanR

    DanR Diamond Level Sponsor

    Jan, What do you have to say about the SV axles? They are a bit larger/stronger and seem to work fine in my V6 applications.
  14. 65beam

    65beam Bronze Level Sponsor

    s looking for someone
    FYI, I have an NOS spider gear set including the pin if you know anyone that needs it. Still wrapped in the greasy paper and gears still have cosmoline.
  15. Eleven

    Eleven Gold Level Sponsor

    Although off topic, when I was racing my Alpine and then Spitfire years ago (mid "70's) welding spider gears was considered the way to go for low powered/low weight cars. That was based off something that Mark Donahue supposedly said but who knows. What you got was the paddock turning radius of the Queen Mary so as not to break axles and a car that understeered like a pig, especially when wet. We didn't know any better so did all kinds of stuff to compensate. My two cents.
    Thinking of welding the water channels if I am unable to get a better replacement.
  16. alpine_64

    alpine_64 Donation Time

    Welding the cresent water passages up and drilling holes has been a long running trick for rootes alloy heads. Mostly to deal with the cresent corording beyond the gasket.

    I did it without prior knowledge back in 2000 when i had lost yet head gasket blowing out the thin area between the cresent water passage and the chamber. In my case it wasnt the cresent being to large but high compression causing failure.

    I had a csyom gasket made with 2 matching holes that then lasted over a decade of daily driving and probably would have kept going had a friend not overheated the motor.

    Ive always wondered if the cresent was there to allow the water to puddle around the cheamber where the spark comes from to help cool further along that edge. I assume the reduced area of water might reduce some cooling in the chamber but i didnt notice any difference in water temp...but maybe it has some effect on combustion.




    PROCRAFT Gold Level Sponsor

    Brad's called me several times and asked about building him a rear end,I suggested a Toyota or Ford or, where you have options as to ratios.

    PROCRAFT Gold Level Sponsor

    Regarding welding if I was doing it id be using 4043 used to use a lot when I welded VW heads the key is cleaning,preheating.
  19. 65beam

    65beam Bronze Level Sponsor

    Doug and I discussed today the change to a ford or Toyota rear. At least parts are available.

    PROCRAFT Gold Level Sponsor

    That's what I told Brad several times, I told him also to use Moser for the work,and I have him a contact in NC that might be able to help.

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