Metallurgical engineers

What all the problems of mig welding on an aftermarket steel, not cast, flywheel? Hardening, brittleness? Kinda doubt it would warp, but.. Submerged welding process would be better I guess.

I would think cracks or thermal induced stress concentrations that could become cracks would be the issue. Where does it need welded? That may matter. Also cost... welding vs new flywheel?

Just buy the proper flywheel, you been farting about with this one for weeks.

I normally don't ask questions, I just do it.
Anyway I got a new idea.
Heaven forbid anyone who welds something, doom and despair.

Welding on a flywheel? Well, first off I think you would have to know EXACTLY what steel grade you have. There are many versions of "steel". Secondly, all welding processes introduce stresses into the base metal. When a liquid metal solidifies it shrinks, thus the stresses. So IF you were able to identify the base metal AND you were able to get an applicable welding procedure, I would think you would have to stress relieve the flywheel after welding. And then contend with potential distortion.

PS, there is nothing magic about the sub arc process.

Why are you trying to weld it and where are you welding?

Good lord, I would never, ever have contemplated the thought of welding a flywheel. That is based simply on intuition. Many things can and should be welded, (I just had a fair amount of welding done on my K frame, including the perch that holds the motor mount in place), but there are things that to me should not be repaired or welded. A flywheel is one of them.

Heating metal to welding point does change the crystalline structure of the material, to whatever degree. In some cases it is negotiable, in others not so. So essentially you now have a spinning object with considerable centripetal force and differing, uneven crystalline structure throughout, directly perpendicular to your feet and lower legs.

That is not based on any scientific investigation or knowledge on my part, but unless convinced otherwise, that is something i would never do!

Beside that you have a surface that will have a different hardness and will lead to clutch chatter quickly.

You need to be more specific if you want an engineering answer. Lots of flexplates are weldments. A flywheel could be a welded assembly if the design was correct. TIG is probably better than MIG but it all depends what you are trying to do.

time for a new flywheel. if you MUST weld it, at least be sure to spend significantly more than a new flywheel would have cost...

Pretty much every torque converter is welded back together plus the starter ring is welded on.
Crankshafts are welded up everyday to put back in service, (I guess they glue that Mallory metal in), I could go on. So what I'm hearing is a spinning flywheel is more critical than a spinning t converter or driveshaft?
I'm sure I'll get another flywheel, don't have the time to tinker with it. Plus I don't think it fits that bell housing either, too deep. Would still like to hear from an expert on the subject. Is there one out there?

HOLD ON GUYS!

What part of the flywheel needs welding? Did the starter ring come loose? Was a bolt hole damaged? Was it broken in half and he's trying to put it back together?

If it's not a deep fissure being welded on the surface of the flywheel it's likely okay to repair.

I'll bet you a $20 bill that if you find an 'expert' they are going to ask the same basic question I did, what 'steel' do you have? Unless you know that no knowledgeable 'expert' is going to touch your question. I'm no 'expert' but I got into a lot of weld repair during 41 years in power plants, mostly successful some not so. I saw an 8" shaft on an ash pump crack completely through at a weld build up in the packing area. Reason? High carbon steel shaft and no stress relieving after welding. I hate to be critical but you still haven't indicated just what you are trying to do. As such, examples such as ring gears, convertor weights, and crankshaft journals may or may not be applicable as they aren't subject to the forces a flywheel is. As with a lot of things in life, it all depends.

Reality: A new steel flywheel will cost you less than welding an old one.

Theory: If you wanted to resurface a steel, not cast iron, flywheel, it could be done by running a continuous bead from the ID to the OD of the wheel, then facing it off. That would give an even hardness across the surface and would probably work out well. That's the only way I'd say welding the working surface of a flywheel could be done with satisfactory result. You'd probably need a welding procedure for the particular type of steel from which the original flywheel was machined. It may need to be stress relieved or normalized or another post-weld heat process.

Comment: I agree that most of the hysterical responses you got were meaningless, except they all pointed to the fact that it is far easier to create a problem welding a flywheel than it is to do the job properly. Avoiding hard spots is one area of concern.


There is another problem that was hinted at and that is weldability. Not all steels are equally weldable. But they are many many times more weldable than cast iron.

Supposing this was a flywheel for a Stutz Bearcat, it'd probably pay to develop a weld procedure and have it properly performed. But the Stutz's wheel is probably cast iron so the issue is moot. For a more modern vehicle, it will most likely be better to buy a new steel flywheel.

R.

Ok, build up the outer edge 1/8 inch so the ring will fit. 3/8" wide. I have no idea what type of steel, whatever's common for an aftermarket blow proof wheel, sliced off of a bar is my guess.
I would add the weld would not be within 1-1/2" of the clutch face.

I fail to see how pointing out legitimate potential pitfalls of a proposed course of action qualifies as "hysterical responses". But that's just me.

Yep, there is.

But he has a good memory.

Now THIS is what happens when you weld a flywheel, boys and girls, every single time!

So let that be a lesson to you, DON'T DO IT!!

The first attempts of a planetary trans from what I remember, lost part of his foot.. Of course I won't use that much percentage of nitro on my street car.
I'll only listen to the ones who stayed at the Holiday Inn too.

I am curious, how did you get a mismatched flywheel and ring gear that is off by 1/4" on the OD?

Short answer, 66-69 Hemi wheel, direct drive starter, ring is on the clutch side, all others are on the block side, 318 to 440. I guess they machined the back side smaller so idiots wouldn't put the ring on the wrong side, or maybe for bendix clearance?
One of the many "bright" ideas from Chrysler.
The only reason I'm pursuing this is that its a brand new, premium steel, made in the 60s- 70s USA product, not some new Chinese stuff.

If it's a full perimeter kind of thing I'd be tempted to make a ring from flat stock and use a few short welds to hold it to the flywheel. That would induce far less heat and stress than a full perimeter weld.

Don't they make epoxies now that are stronger than welds?

I bet they even make flywheels that actually fit

Make a ring the proper interference size to fit your flywheel and ring gear, then heat it and place it, let it shrink, then heat the ring gear, place it and let it shrink, been there done that!!

I'd gob that up with some Liquid Nails or JB Weld or Bondo even.

You got it, ta da. Exactly what I been thinking all day, and will do, 1/8 X 1/2 rolled and welded in a circle ever so slightly bigger then the inside of the ring gear, heat the ring to fit the spacer then the same on the wheel, tig weld a few spots for good measure, done! Test it to 10,000 rpm a couple times, if it stays on, run it.
A simple fix for a simple item, it's not the space shuttle going to Mars.
Thank you all for your answers, the good and not so good.