1936 Chrysler Airstream C-8 Convertible Restoration

[Bloo]

In my opinion, get the manifold professionally fixed, and by someone who knows what they are doing. Chrysler eights are notoriously hard to find spares for. You probably don't get another manifold if the repair does not work out. Drilling the end of cracks is not something that usually works. It only stops the crack if you get the hole at the true end of the crack. Usually the crack goes further than you can see, and might split at the end. There is a good chance the crack will continue to propagate despite the drilling. JB Weld is completely inappropriate for this, or for anything else that gets as hot as an exhaust manifold.

 

 

[Professor]

Here is the crack:

 

 

[VW4X4]

1 hour ago, Professor said:

Here is the crack:

 

 

WHile.....  that's no small crack... That has to be fixed or replaced... You definitely need a pro for this, although I think a pro sees this as an easy fix.  This has to be heated to be welded. I would take this up to over 800 deg.   At this temp. it might start glowing red, but will be very easy to weld.  Once the weld is complete, you want to very very slowly cool this.  Basically this is what stress relieving is.  Then  re-heat and cool again.  At that stage if the weld has not cracked, its not likely going to. 

 

ERIC

[Professor]

I have a Miller MIG welder and the ability to heat this part to 500 F, and I purchased some .035 nickel wire. I think I am going to practice on an old cast iron skillet and see if I can do this myself. I am a fairly proficient welder, but have never touched cast iron before. If I can get decent welds with no cracking, on my wife’s cast iron, I may give this a shot. I found a replacement exhaust manifold, but at $900, I really need to either get this piece welded or do it myself. I have some calls in to a couple of local welding shops, but have not heard anything back yet… things move slowly here in the south. 🙂

 

Joe

[VW4X4]

1 hour ago, Professor said:

I have a Miller MIG welder and the ability to heat this part to 500 F, and I purchased some .035 nickel wire. I think I am going to practice on an old cast iron skillet and see if I can do this myself. I am a fairly proficient welder, but have never touched cast iron before. If I can get decent welds with no cracking, on my wife’s cast iron, I may give this a shot. I found a replacement exhaust manifold, but at $900, I really need to either get this piece welded or do it myself. I have some calls in to a couple of local welding shops, but have not heard anything back yet… things move slowly here in the south. 🙂

 

Joe

COOL.....  The beginning of the crack looks like someone has ground a small amount of metal out of it.  Your going to want to do this through out the entire crack.  Its the only way to ensure the entire crack gets welded.  The amount you grind out is very important.  To much and you'll burn thru, to little and the weld will not penetrate.     Also, keep things very clean.  As I'm sure you know any  rust or dirt will degrade the weld. 

           Just think 25 years ago that $900 manifold would have been scrapped for the price of metal.  Now with the internet, the sky is the limit.

 

ERIc

[Professor]

I am still waiting on the wire so this part of the rebuild is going to have to wait.  I purchased an inexpensive but highly rated valve seat grinder on Amazon so I am going to work on the valve seats and drop off the new exhaust valves and old intake valves for a touch up. The new exhaust valves use a different keeper than the old valves, and the valve springs that Andy Bernbaum show as “1936 all” are too short for my 8 cylinder so back they go with the incorrect valves.  I am less than impressed with the folks who took over from Andy.

 

I need to take the aluminum spool feed off the Miller and set it up for iron and play around with some scrap.  It has been a couple of years since I welded anything but aluminum (our horse trailer is aluminum and the horses beat it to death).  I need to chase some threads on the intake and exhaust manifold studs and do some other minor work, but I am at a bit of a standstill until either the nickel wire for the welder or the valve seat cutting tools get here.

 

Oh… one other thing; the valve keepers on the new exhaust valves are different than the keepers on the old exhaust valves so I need to track down new keepers.  Gotta love a hobby that keeps you hopping.  🙂 

 

Joe

[Professor]

By the way, I measured the length of the intake valves in my engine and they measure approximately 5.400”. I measured the old (failed) exhaust valve length and they measure 5.365”.  I measured the length of my new (and correct according to my parts book) exhaust valves, and they measure 5.435”.

 

So… it appears that the failed exhaust valves in my engine were shorter than the intake valves, and my new exhaust valves are longer than the intake valves.  Should I be concerned here?  By the way, I tested the new exhaust valves with the smaller head diameter and they ride at about the same height in the head that the intake valves do.  I honestly believe that the exhaust valves in this engine were not correct, and that the .2” increase in head diameter may have contributed to the failures I see in the exhaust valves.  I have not uploaded closeups of the other exhaust valves that were failing, but you can see that the edges of the valve head are cracking in a pattern similar to the cracking failures seen on the top surface of the valve.  I can literally chip away the edges of the top surface of several other exhaust valves with my fingernail.  While cylinder 3 was the worst, three other cylinders had exhaust valves that were beginning to fail in a similar fashion.

 

More images this weekend.

 

Joe

[VW4X4]

17 hours ago, Professor said:

By the way, I measured the length of the intake valves in my engine and they measure approximately 5.400”. I measured the old (failed) exhaust valve length and they measure 5.365”.  I measured the length of my new (and correct according to my parts book) exhaust valves, and they measure 5.435”.

 

So… it appears that the failed exhaust valves in my engine were shorter than the intake valves, and my new exhaust valves are longer than the intake valves.  Should I be concerned here?  By the way, I tested the new exhaust valves with the smaller head diameter and they ride at about the same height in the head that the intake valves do.  I honestly believe that the exhaust valves in this engine were not correct, and that the .2” increase in head diameter may have contributed to the failures I see in the exhaust valves.  I have not uploaded closeups of the other exhaust valves that were failing, but you can see that the edges of the valve head are cracking in a pattern similar to the cracking failures seen on the top surface of the valve.  I can literally chip away the edges of the top surface of several other exhaust valves with my fingernail.  While cylinder 3 was the worst, three other cylinders had exhaust valves that were beginning to fail in a similar fashion.

 

More images this weekend.

 

Joe

The length of the valve is not that important.  As long as it opens and closes, and there is room to adjust. The same goes for the seat.   As long as it properly sits on the seat. 

That said, a lot of valves today, are special materials. Racers years ago would by sodium filler valves, that would put up with the heat. I haven't kept up the technology, but I assume today's valves are all some sort of special metals like this.  Maybe those valves that are falling apart just happen to be very old left overs... That's the real problem with these old engines in general.  New old parts, are just as bad as they were back then.  You can easily make lots of improvements if you want to spend the money.  Someone, I'm sure, would know more about valve technology than I.  Maybe drag racers would know where to get real good quality valves....

 

ERIC

 

ERIC

[Professor]

Ready to go... waiting on the nickel wire.  If I screw this up, I only have me to blame.  I will be operating on one of my wife's old cast iron skillets with a broken handle.  If I cannot weld her skillet, then I will take it to a shop in Raleigh who said they weld cast iron and let them do it.  I am pretty confident... I think... LOL.

 

 

[Randiego]

Joe,

Since you only have one exhaust manifold, I would be really leary about trying to weld the manifold yourself.  I give you a gold star for wanting to do it but.........even professional weld shops are nervous about welding cast iron.  I had the same issue with my 36 Pontiac exhaust  manifold.  There was a crack that did not show up until the machinist magnafluxed it.   When he showed me the crack, I knew I was in for a real challenge.  I went to three shops before I found one that would do the job.  When I went to pick up the manifold, the tech told me that he had the dickens of a time because of the age of the iron.  80+ years subjected to heating and cooling can crystalize the metal.  Molecular changes happen with cast iron and it is a very difficult material to repair.  The previous commenter regarding heating up the manifold, slowly cooling, reheating etc., etc.  knew what he was talking about.  I would think real hard about attempting to repair the manifold yourself. 

Since that part is from the planet "unobtainium", a screwed up weld can give you more grief that you bargained for.  And you are just in the beginning of this project.  Who knows what else is lurking around the corner waiting to rear it's ugly head in your journey?

 

As to the finish on the exhaust manifold(s).  My machinist has been using a heat paint from NAPA.  He bead blasted the manifold ensuring that it was absolutely clean, sprayed it then heated it up in his oven to 250 degrees.  To this day, the manifold is still "steel grey" exhibiting no signs of any rust.  I will try  to take a picture of it and post it (if I have a bit more time).

Good luck, Joe.   

[JimKB1MCV]

I've got to say "+1" to the above.

FWIW, I'd respectively suggest if you have found a uncracked manifold for $900 it might save you

$800 in heartburn.

 That said, I wonder if the iron where the crack is located is thick enough for a stitching repair?

[F&J]

On ‎4‎/‎9‎/‎2022 at 9:40 AM, Professor said:

Ready to go... waiting on the nickel wire.  If I screw this up, I only have me to blame.  I will be operating on one of my wife's old cast iron skillets with a broken handle.  If I cannot weld her skillet, then I will take it to a shop in Raleigh who said they weld cast iron and let them do it.  I am pretty confident... I think... LOL

You have a great mindset.   I also would also be looking forward to trying to do it myself.  I would think the thin skillet handle might be more likely to fail compared to the manifold.  You are obviously not doing it to save money; you just want to try it.   The guy at your local welding shop, he once was a guy who never had welded cast iron before.  Now he can.

 

One of my neighbors gives lectures about the phrase; "what if". Meaning that all through life, a person can back on doing many things because something negative might happen.  

 

The location of that crack and size, makes me think it won't be a real bad risk.  It needs to be deeply Vee'd out a lot more, right to both ends of crack.  Some guys lightly hammer the bead to relieve stress

 

 

[Professor]

My plan is to stop drill both ends of the crack and V out the edges to get a good weld.  

 

I will put a propane grill with a closed lid right next to my welding table and welder and throw the manifold on the grill (which has a lid) and heat it to as hot as I can get it (the thermometer on the grill goes up to 600F, we will see if I can get it to 600.  Once the manifold is hot, I will put it on my welding table and weld a short 1" weld, tap the weld, and put the manifold back on the grill and close the lid.  I will repeat this process until the weld is done and the manifold is back in the grill.  Then I will slowly lower the temperature of the grill over a 10 hour period until the temperature is as low as it will go.  Once the manifold stabilizes overnight at the lowest temperature, I will pull it off and drop it into a pile of sand (already in my wheelbarrow) and bury it.

 

If this process doesn't result in a strong weld with no cracks, then I am at least confident I did the best I could.  I will have the correct wire, shielding gas, and thermal control process in place (I think).  What could go wrong?  ROTFL.

 

I will post the results here when I am done.  

[Professor]

Looks like the experiment begins this weekend…

 

 

[Laughing Coyote]

I repaired both my cast exhaust manifolds on my 61 Mercury and they are thin.  I watched a Youtube video where this old guy got a Weber charcoal grill and made a fire in it.  Then placed the manifolds on the grate for a bit and let them get heated. He then used an arc welder with a cast iron welding rod and welded the cracks.  After that he put the lid on it and let it sit until cool.  I did the same thing and mine haven't cracked yet.  I'm sure if you used the same approach,but use the nickle wire it should work out also.  

[Professor]

I am using the MIG version of the cast iron welding rod.  The combination of the cast iron MIG wire and the Argon CO2 shielding gas should produce similar results.  I have not stick welded in close to 30 years, I would hate to see what one of my stick welds would look like now.  Actually, now that I think about it, I would hate to see what my MIG welds look like now.  🙂. 

 

4 minutes ago, Laughing Coyote said:

I repaired both my cast exhaust manifolds on my 61 Mercury and they are thin.  I watched a Youtube video where this old guy got a Weber charcoal grill and made a fire in it.  Then placed the manifolds on the grate for a bit and let them get heated. He then used an arc welder with a cast iron welding rod and welded the cracks.  After that he put the lid on it and let it sit until cool.  I did the same thing and mine haven't cracked yet.  I'm sure if you used the same approach,but use the nickle wire it should work out also.  

 

[Laughing Coyote]

It sounds like you got it covered.  The heating up the manifold prior to the welding and letting it cool slowly is the main thing.  I tried welding cast iron before pre heating and it didn't work very well.  Good luck.

[Professor]

Good morning/afternoon all.

 

I have finished welding the manifold and am letting it cool down in the oven (with the burner on, slowly lowering the temperature).  I think I may have figured out why the manifold cracked in that area.  First, the cast iron in the area of the crack is incredibly thin.  By my estimation, it was about 14ga, and the thickness across the manifold area running parallel to the crack varies substantially.  In some areas, I had to adjust the voltage up to get good penetration and in other areas, I had to adjust it way down because of how thin the manifold was.  I ended up building up the thin areas.  I have been listening for the “tink-tink-tink” sound associated with thermal related cracking and so far, have not heard anything. Here are a few images of the setup prior to welding.

 

Joe

 

 

[VW4X4]

What is your wife going to say when she opens the grill with stakes in her hands and finds your exhaust manifold part?

 

Once it cools completely, and you carefully examine it for cracks, re-heat it at least once again.   If it survives the second re-heat, its highly likely not going to fail from a temperature issue on the car.

 

   Heating weldments  (large steel pieces welded together ) and re-heating is what is known in the metal fabrication industry as "stress revealing".  This is a common proccess  for metal fabricators.  Its done not just for cast iron, but lots of large steel processing.  At those high temperatures hopefully the metal becomes soft, and and stress from welding will move just enough so that the materials do not crack.  The longer it is at those high temps. the better. 

 

ERIC 

 

[Piaras]

Looks pretty good set up. Slow cooling is the trick as you know.

We are always stress releasing and annealing our metals, especially after doing rolling work to reduce their thickness. Even when it gets down to 0.002” it still needs it done! 
Pierre

 

[Professor]

All done, no cracks.  I am not particularly happy with the voids in certain places, but they are all in areas where there was no crack, and none of them go through.  I found that as I welded, contaminates seemed to come out of the cast iron, and in certain places, caused the puddle to pool and actually run off.  I had this part cleaned and sand-blasted, and then I cleaned it with acetone… and still, contaminates caused voids (or at least, I think they were due to contaminates and not the fact that I suck as a welder).

 

Here are a few pictures.  I will take it back to my machine shop and have the surfaces trued and the part sand-blasted again.  I would love to have some pointed critiques of the final product.  The perfectionist side of me wants to fill those voids, the realist suggests that perfection is not worth a possible stress crack.  I look forward to comments.

 

Joe

 

 

[Laughing Coyote]

Cast materials (aluminum or metal) are very pourous and can hold contaminants that will come out when welding even if it's been cleaned.  Glad it worked out, mine wasn't very pretty either, but I have no cracks or leaks. 

[Professor]

All,

 

I finished the second heat cycle to 650 and back to zero with no cracking evident anywhere.  I actually sat in the garage during the cycles to listen for the telltale “tink tink tink” sound of cracks forming, and I did not hear any sounds.  I will have this piece surfaced on the side that mates with the exhaust manifold on Monday. I cut the valve seats for all intake valves today and will have the (reused) intake valves re-ground on Monday.  I will cut the valve seats for the exhaust valves tomorrow and clean up the valve adjustment area tomorrow using brake clean.  I will drain the oil and put fresh oil and a filter in after I hone they cylinders.  I have small hole ball gauge measuring instruments to measure the valve guide wear.  I will post the measurements tomorrow and check with the experts here to see whether or not I should pull the valve guides and replace them.

 

Standby for more tomorrow.

 

Joe

[Professor]

Intake valve seats. 
 

 

[VW4X4]

Joe,

   To measure the valve guides, in modern day engines, you place a new valve in the guide only to the end of the guide.

Then with a dial indicator measure the side to side movement.   I show this simple way in my video.... I don't know if you watched it.  Obviously I don't have the dial inductor  on it.

    As I noted this one is still within specs.

         ERIC

 

[Professor]

Thanks Eric.  I am watching it now.

[JV Puleo]

You might try this stuff to fill the voids...supposedly it gets stronger with heat. In any case, it's recommended for use on a sandblasted finish so you are half way there already.

 

 

I have used it when I repaired a 1920 Cadillac water pump. I "V'd" the crack, silver soldered it and used this stuff to hide the V what was left of the groove.

Edited April 16, 2022 by JV Puleo (see edit history)

[Boobtube]

On 4/5/2022 at 10:16 AM, VW4X4 said:

Well that sure is a interesting way to pay for a car!  Almost as bad as making an offer on a car and the seller comes back with a lower price!!     I guess this a is a good example of where money becomes a lot less important.

 

As for the work your doing on this car....   I have little or no interest in vehicles that have had a "Complete restoration" anymore. I've looked at way to many "complete restorations" that are not so well done.   Many of these end up loosing lots of originality and detail , that they will never ever get back.  Better off left alone, than to butcher or molest  like most are being done today.

 

ERIC

I, too, am a fan of keeping it original if at all possible.  I can also understand the desire of some to make them showroom new.  The market seems to reflect this desire to maintain originality as they are sometimes commanding bigger prices.  They are original only once, after all.  But I have seen some stunning restorations.

[Professor]

Good evening all,

 

I received this from Chrysler today:

 

Hello Joe,

 

Thank you for your patience while we work through our backlog of orders.  Unfortunately, the build record for your serial number 6715475, was missing from our microfilm files and does not exist within the company.  I have attached specifications for this model.

 

I am very sorry we could not help you further with this.  If you have any questions, please let me know.

 

 

Danielle Szostak-Viers

 

Stellantis Historical Services

12501 Chrysler Freeway

CIMS 410-11-21

Detroit, MI 48288

 

// end email

 

It makes me wonder what happened to the build record.  I have decoded the body tag on the firewall, so I know how the car was equipped, but the build card would have been cool to see.

 

Back to lapping valves and welding cast-iron.  🙂. 

[Steve9]

Sorry Joe, I’m know it’s disappointing such a premium car as yours has no corporate pedigree. But my original offer stands in my first communication with you on the forum, I will accept a trade!

[Randiego]

Joe,

Congratulations on your cast iron weld.  It looks great considering that all the impurities bubble to the surface during the welding process.  

I do not know if you are looking to put a finish on the finished manifold, but NAPA has a metal heat paint (not the engine paint) that my machinist used on my 36 Pontiac 6 cyl. exhaust manifold.  After he sandblasted it to clean the  surface, he heated it to 2or 300 degrees in his oven.  The final finish was "cast iron grey" and has not discolored in over 2 years.  I do not have the paint product or I would include it here but you can get it at NAPA.  They should know what that paint is.  As to your weld.  You did an amazing job for not welding cast iron before.  That is the most tricky of materials (the most difficult is magnezium) to get a successful weld. 

[VW4X4]

Joe,  How's the straight eight doing? 

 

ERIC

[ryan95]

Fantastic job on the weld. I doubt that as nice of a job would have been done by many places. I've found that with research, patience, and practice there aren't many jobs that aren't doable. As long as the cost of tools and materials isn't higher than what you would pay a pro, I'm all for learning a new skill. One last thing as a joke that I heard once, a grinder and paint makes me the welder I ain't. There is some truth to it though if one of the goals of the weld job is to make it look like it was never there.

[Professor]

Good morning all,

 

I am back to work on the Chrysler today.  I need to continue cleaning out the valve train area from all of the lead deposits that have built up and then I will lap the intake valves and potentially install them depending on how long it takes to lap the intake valves.  I also have a cylinder hone and will be honing the cylinders if this is something that can be done with the pistons installed.  I do not want to take the chance of putting debris into the piston ring area, and I “think” I can protect the rings by cleaning and taping around the base of the cylinder bore with the piston at the bottom of the cylinder, but I need to do some more investigation before I hone.

 

Today will be an easy day, I think.  I am of course assuming that lapping the intake valves will not be difficult.  Famous last words.

 

Joe

[Professor]

First…. The good news:

 

I managed to remove all three of the damaged head studs without breaking anything.  The remainder of the studs are all in good shape so I need to order the replacement studs and all new retaining nuts.

 

Now for the bad news:

 

I started lapping the intake and exhaust valves.  I started with cylinder 8 since it is the most difficult to reach.  The new exhaust valve lapped perfectly.  I started lapping the existing (used) intake valve and the pattern had virtually no margin.  What the heck?  I then measured the head diameter: 1.376”.  What should the head diameter be?  1.468”.  Sheesh.  It turns out the exhaust valves that were installed in this engine were oversized and the intake valves were undersized.  If I cannot find the correct Thompson V-834 intake valves, I will need to head off to Egge and spend $54 per intake valve.

 

Just to end on a high note… I cleaned up the cylinders and piston tops, the top of the block, and the intake and exhaust manifold side of the block and everything looks great.  No cracks or issues that I can see.

 

Time to go find some intake valves.  🙂

 

Joe

[2carb40]

On 4/6/2022 at 8:13 AM, Professor said:

Here is the crack:

 

 

Crow River cast welding in Hudson WI. Previous owner let engine tip over on this flange ear with stud closest broke off dangling by collar, triangle shape piece was missing. Highly recommended! Spoke with others, same responses.

[Bloo]

Honing is never desirable with the pistons in.

 

Edited April 24, 2022 by Bloo (see edit history)

[Professor]

Thanks Bloo.  I will leave the cylinders as they are.

 

On 4/24/2022 at 4:01 PM, Bloo said:

Honing is never desirable with the pistons in.

 

 

[Professor]

30 April Update:

 

Egge intake valves came in yesterday and I started lapping the new intake and exhaust valves.  Lapping patterns are perfect now, although I have only completed two cylinders.  One bit of really good news is that with new valves, the valve guides show virtually no lateral movement; I will not need to replace any valve guides.

 

I need to purchase new valve keepers since the keepers that were on the incorrect intake and exhaust valves do not work on the correct valves.  I also need to purchase the new head studs, new nuts for the head, and new brass nuts for the intake and exhaust manifolds.

 

I will be taking in the now repaired exhaust manifold to have it vatted and surfaced and order the paint I need for both manifolds and the head (which was painted silver).

 

I also welded a couple of really small cracks around the automatic choke mount and I can say with absolute certainty that welding cast iron is not difficult if you have the correct materials (cast iron MIG wire) and heat the components prior to welding and then slowly cool them.

 

I need to find the correct eight cylinder water pump for the CZ C8, or, weld my water pump housing to repair the broken tab.

 

I look forward to getting my C8 back on the road.  I really miss driving it.

 

Joe

[keiser31]

1 hour ago, Professor said:

30 April Update:

 

Egge intake valves came in yesterday and I started lapping the new intake and exhaust valves.  Lapping patterns are perfect now, although I have only completed two cylinders.  One bit of really good news is that with new valves, the valve guides show virtually no lateral movement; I will not need to replace any valve guides.

 

I need to purchase new valve keepers since the keepers that were on the incorrect intake and exhaust valves do not work on the correct valves.  I also need to purchase the new head studs, new nuts for the head, and new brass nuts for the intake and exhaust manifolds.

 

I will be taking in the now repaired exhaust manifold to have it vatted and surfaced and order the paint I need for both manifolds and the head (which was painted silver).

 

I also welded a couple of really small cracks around the automatic choke mount and I can say with absolute certainty that welding cast iron is not difficult if you have the correct materials (cast iron MIG wire) and heat the components prior to welding and then slowly cool them.

 

I need to find the correct eight cylinder water pump for the CZ C8, or, weld my water pump housing to repair the broken tab.

 

I look forward to getting my C8 back on the road.  I really miss driving it.

 

Joe

Can you post a photo of the water pump so we can see what to look for?