Tig Welding Cylinder Heads

[coronan]

This is a personal project. The alternative to welding it is i need a new head any way so why not try to save it. This is my screw up while porting. My Loss is only to be gained from attempting repair.
Here is the damage.



My question is If you were to weld it how would you set it up????

The port is about 1.7" dia
The hole, needing fillled, is a little over an inch reach from the edge.
The hole opens to a crank case oil return passage. (no pressure).
Welding position is OVERHEAD on aluminum. (in the car.)

My setup is currently a
D200 ,@ 90 hz, CK17 torch, small gas lense, #8 alumina cup, 3/32 2% Ceriated, 30cfh argon, BOUT 1.2" stick out..

I have struck up an ark in there but felt like i was not getting gas coverage.
Argon is heavier than air.

Should i switch to a long clear cup?

How would you do it?

[taylorkh]

I have not done this myself but I did look into it a couple of years ago when a friend had an Alfa Romeo head which had eaten a valve and needed repair. I came across the web site of a company which was in the business of repairing aluminum cylinder heads. Among the things I learned:

1 - It takes a LOT of amperage - 350 - 400 amp machine at least
2 - Preheating of the head is critical
3 - Controlled cooling is also important to prevent post weld cracking.

I concluded that my Dynasty 200 DX did not have the capability for the job and the wife would not be happy with me roasting a cylinder head in the kitchen.

For $100 he found a replacement head on evilbay and after speaking with the seller acquired a whole bunch of other parts for free!

For what its worth,

Ken

[Mikey Welds]

Tig Welding Cylinder Heads

Scrap it, find a cheap good used head and give it a thorough 5 angle valve job. This will give you a much better shot improved performance than any amateur porting job IMO. As you have learned in a most painful way, 90% of all porting jobs, even when done by a so called pro, don't achieve much, and can do more harm than good.

[Portable Welder]

I don't agree with TaylorKH, It looks pretty thin to me so you wont have a ton of amperage input if that's the case, By the sound of it you have nothing to loose but time and a little material.

A friend of mine welds on heads all the time for the big time racers - Ford motor company without a oven.

Worst case scenario is that you learn something and have to buy a new head.

[coronan]

I've never thought i'd come to a welding forum to be told not to weld something.

MY question is more specifically how to see what I am doing and lay a quality bead.
My concerns are
1. the overhead position and argon being heavier than air.
2. excessive tungsten stick out over an inch.

Here is more perspective:





Maybe the title should say "welding in deep holes/ tight areas".

[Meltedmetal]

I am probably not the one to advise you on this but if I understand correctly the head is still on the engine in the car. If this is correct and you want a reasonable chance of success, take the head off the engine and put it on the bench where you can manipulate it easily to work on. ---Meltedmetal

[Cgotto6]

Why are you porting a head installed on a car? Or did you discover the leak at first start up? Either way, you need to remove it to have any chance at all, plus you will need to grind the new weld down to get the port back in shape and hopefully you know better than to grind in a head port while it's installed on a motor.

What car are you working on?

[H80N]

This is a personal project. The alternative to welding it is i need a new head any way so why not try to save it. This is my screw up while porting. My Loss is only to be gained from attempting repair.
Here is the damage.

[ATTACH]34674[/ATTACH]

My question is If you were to weld it how would you set it up????

The port is about 1.7" dia
The hole, needing fillled, is a little over an inch reach from the edge.
The hole opens to a crank case oil return passage. (no pressure).
Welding position is OVERHEAD on aluminum. (in the car.)

My setup is currently a
D200 ,@ 90 hz, CK17 torch, small gas lense, #8 alumina cup, 3/32 2% Ceriated, 30cfh argon, BOUT 1.2" stick out..

I have struck up an ark in there but felt like i was not getting gas coverage.
Argon is heavier than air.

Should i switch to a long clear cup?

How would you do it?

IN THE CAR...???

I would not attempt it in the car with the head mounted to the engine..

If it is a small 4cyl head I think the Dyn 200 is not your limiting factor...

maybe up HZ to 120

would reduce Argon flow to about 20 CFH.... think 30 might be causing some turbulence and pulling in air to contaminate weld puddle... too much stickout too imho...

a 17 series torch sounds too bulky to get where you need to be... especially with a gas lens...I would ditch the gas lens for this.. do you have a pencil or 24 stubby series..?? one of those should get you into the right spot either from the valve side or port side

might want to cut back to solid material and weld in a patch rather than trying to build up the broken out area..

my 2cents worth.. not being near enough to see the whole picture...

[FusionKing]

I've never thought i'd come to a welding forum to be told not to weld something.

MY question is more specifically how to see what I am doing and lay a quality bead.
My concerns are
1. the overhead position and argon being heavier than air.
2. excessive tungsten stick out over an inch.

Here is more perspective:

[ATTACH]34682[/ATTACH]

[ATTACH]34683[/ATTACH]

Maybe the title should say "welding in deep holes/ tight areas".

It will not weld with the tungsten out that far. I wouldn't worry about the heavier than air thing. Everybody welds overhead all the time with argon.
Like you said....what do you have to loose?
If it was mine I would set it on sine wave, balance at 72 with frequency at 60. Burn the hole all around the edges carefully, and then clean it again. There is likely a lot of crap in the water jackets. Then I would use 4943 filler or 4043 and weld it up. I would weld over to sides of the hole all around just to make sure it flowed in nicely.
If you can't see it I would try a pencil type torch. Bear in mind most of the special torches are light weight rinky-dink without AC aluminum in mind.... so you are amps limited.
Also almost every piece of advice you received here is pretty good stuff. Just because you found a thin spot doesn't mean you aren't right next to a thick one that may take a lot more amps than you expect. Being bolted down to a block could soak up a TON of heat in the right situation as well.
If it doesn't work then take it off and charge more money to do it correctly.
Just my 2 cents worth YMMV

[cruizer]

Why can't you drill it out, and stuff a bushing in it. Seems way easier.

[sledsports]

My honest opinion is scrap it. Been there, got the tee shirt.

[Portable Welder]

The reason they are telling you to just buy a new head verses welding it is because of the price, personally I would just buy a new head if they are only a couple hundred bucks.

The #2 reason is this will be extremely hard, upside down, inside of a port, contaminated aluminum, you don't have the right torch if you need 1" of stick out, are you skilled at welding dirty aluminum and the list goes on.

However, If you have the time and patience its good to try so you get experience and learn what your capabilities are.

Fusion king has probably given the best advice, you want to go in without any filler and burn the thin edges back until you get into something substantial, then clean the contamination out and after you have done this a couple of times then its time to add filler and weld it.

[gtijustin]

Let me start off by saying this.. If you ported that head while in the car, isn't your entire engine filled with aluminum shavings now? Even if you had it sealed up somehow, when you broke through into the crankcase oil return passage, I'm sure all sorts of stuff went down into there, so it sounds to me like that hole is about to be the least of your worries, but that wasn't your question so hopefully you have that sorted out already.

As far as welding that, I don't think it's crazy to try, like you said, even if it doesn't work you really have nothing to lose, however, you have a lot more to lose by trying to cut corners and not remove the head. Call me overly cautious, but the chance of you starting a large fire that ends up ruining a lot more than that head is more of a risk than I'd be willing to take. Taking the head off will make everything a million times easier, you'll be able to properly clean and prepare both sides of where you're going to be welding, and it will also allow you to back purge that weld through the crankcase oil return passage, solving your gas coverage problem. There's nothing wrong with sticking your tungsten out an inch as long as you've got enough coverage and a steady hand, and with argon flowing from the cup and in from the hole you should be golden. I like the idea of starting out by burning those edges back, then I'd cut a patch piece, fuse it to the end of a piece of wire so you can hold on to it, stick it in there and go to town. Let us know how it goes!

[Cavi Mike]

The alternative to welding it is i need a new head any way so why not try to save it.

Exactly. You have to remove the head anyways. So remove it, clean it, and then try fixing it. At least you have a shot at fixing it if you do it that way.

[Dobermann]

Let me ask a stupid question: If you "ported" that head in place, where did the shavings from the rotary burr go? Into the engine? Yikes!!

If that's really what happened, then how to weld up the hole in the head is the very least of your worries. You'll have to pull the head anyway to get the crap out of the passage way and combustion chamber. Your engine won't like metal shavings one bit!

Throw the head away and get a new/used one and stop screwing around with the porting. The guys who designed it knew what they were doing and might possibly have known more about flow through the ports than you do.