Welding steel to cast iron head?

Gunner Asch fired this volley in news: snipped-for-privacy@4ax.com:

But Gunner, you said the valve cover almost touches the guide towers. It IS an option to attach the guide to the valve cover, instead of to the head. Mmmmm???

LLoyd

I was going to suggest that (since I started the thread), but you'd have to get a whole lot of the thing really hot; I'm not sure what it'd do to the straightness of the head and the valve guides -- certainly if the head has any bits of rubber in it the idea is a no-go.

I'm for the TIG brazing, particularly since it's Gunnar who has to come up with the machine!

I don't think I've ever used phosphor bronze wire, but I have no reason to think it wouldn't be a good choice. Try sticking some scraps of steel and cast iron together and see how it works.

I mentioned sili bronze because it's pretty common and relatively strong. It's not the easiest bronze to use -- it's viscous and acts like there's a skin on the puddle. If I were doing it here I'd use A2 aluminum bronze because I have some, it's strong, and it's better behaved than silicon bronze.

Preheat with a big rosebud (or oven) and tig with stainless

Tigging with stainless actually would make a better job if you had a peice of cast to make the repair with, but this is not a terribly high load application. I'd have been tempted to just build up the damaged area with Stainless rod and grind it to fit, myself.

Looking at the picture, Brazing would work fine - but why not just drill, tap, and fasten with a couple small screws? Permanent loctite and bob's your mother's brother.

Busting out rolling on the floor. Dry cough. & I quit what ever this year's date is ago. That was a good one.

I would have tightened that bolt a CH tighter and been in Hell A away from the warden.

Should be a thick hardened steel rod holding that all together and won't matter much in that direction anyhow. That bolt will hold it another 40k+.

SW

Y'know... all kinds of folks jump ALL over someone for top-posting, but everyone in this thread has quoted the ENTIRE GD OP just to post one- liners.

All the complaining about "style", and not one single soul seems to have any _courtesy_ toward other posters OR the net bandwidth.

It's kind of like straining at gnats, doncha think?

Lloyd

Well, Bob 'was' one of her brothers. ;-)

TIG braze it with some Silicon Bronze filler.

No need to apologize for bailing out at MS?? level, Tim.

4-40 flathead screws with Loctite would work just fine. Even 2-56 screws would probably suffice. It's not a fix a grease monkey would think of, but it'd be easy peasy for a machinist or gunsmith.

A good braze would be stronger, but all that's needed here is "enough". Gunner sez a dozen pounds. Call it 50 for a bit of margin. A bad braze with micro cracks in the surrounding casting, bad wetting, or foaming of the braze alloy would very likely fail, and the likelihood of getting a bad braze is significant for folks like me and Gunner having no experience brazing with TIG. Torch brazing ain't on the menu here unless the head is stripped and preheated, and even with that there is significant risk of warping. The advantage to TIG, if it works, is that you're in and out of there quick as a surgeon with a golf date, leaving a very limited heat-affected zone. The question is what happens in that very limited HAZ. Any crack upon cooling is a failure. Cast iron varies a lot in tolerance; some castings can be welded or brazed without difficulty while others are impossible. I have successfully repaired fractures in the intricate cast iron lattice work on the treadle of a vintage Singer sewing machine, totally failed on the exhaust manifold of an '80's vintage Japmobile.

So I'd either learn and verify a TIG brazing process experimentally on scrap stock, or I'd drill, tap and use flathead machine screws.

I'd go with TIG if I could find some cast iron to practice on, because I have lots of time, 3 working vehicles and no urgent need to be anywhere other than medical adventures with Mary and Mayo. If I were in Gunner's sit, I'd go with machine screws.

Sometimes top posting is appropriate. For example when someone posts just to say " I agree." Nothing worse than to scroll down a page to find the person that replied has added nothing of consequence.

The only thing worse is those that post just to say that the previous poster should have not top posted. I mean to say the idea is to convey intelligence. If someone is too slow and needs everything in the same format in able to comprehend what is going on, they ought to be ashamed to admit it in public.

Trimming is almost always appropriate.

Dan

Looked at the pics. I'd just use a TIG and braze the tab on. The opposite side gets a majority of the torque and I have seen a few 3.0 with broken alignment tabs. Normally I just grab a spare head but if that one has been worked then I would just fix it. Make DAMN sure you keep heat away from the valve springs and keep the head as cool as possible. The stem seals don't like heat and you don't want to have it reworked again if you cook them. Pull it apart if you want to be sure to keep them OK. I would anyway because you don't want any iron swarf in there.

Same here. I'd have screwed and glued before gummer finished his first batch of posts. What happened to the mechanical "knack" he claimed to have? It morphed into "my mechanic"! Have you heard the adage "if you watch an expert long enough, it feels like you're an expert"? Well, gummy discovered that talking was even easier than watching.

Anyway, this is only episode 2 of the Rancho Deadbeato Great Cylinder Head Debacle. Stay tuned for 3 and 4.

Wayne

IANAM, but I'd braze that puppy. 'Course, that should have been done before the springs and rubber seals went back in. Maybe soak the bottom half of the head (lengthwise) in water while you braze to keep the heat entirely away from the rubber parts.

Take ya ten minutes from start to finish. Soak the head, 'tin' the tab, 'tin' the head, heat both, and braze together. The rocker should have a radiused block it rides on so the tab won't get so much pressure against it that it would try to pop off, I don't think.

Was it dropped against something?

-- Not merely an absence of noise, Real Silence begins when a reasonable being withdraws from the noise in order to find peace and order in his inner sanctuary. -- Peter Minard

One could always install the stud, drill and tap 'em, and screw the piece on.

Your buddy Cliffy (or rangerssuck) might do it that way, eh?

-- Not merely an absence of noise, Real Silence begins when a reasonable being withdraws from the noise in order to find peace and order in his inner sanctuary. -- Peter Minard

I suppose if you used 4-40 flatheads, one on either side of the stud, it might work. Brazing still seems best to me.

-- Not merely an absence of noise, Real Silence begins when a reasonable being withdraws from the noise in order to find peace and order in his inner sanctuary. -- Peter Minard

The hole in the center would only attach it to that thin area in the stud path; much less to hold on to.

Couldn't hurt.

Yes. (Means: I have no idea.)

Maybe he knows. Hmm, maybe not. (Their web guy didn't. He linked to the aluminum repair video, and their brazing rod is ONLY $75 a pound.)

-- Not merely an absence of noise, Real Silence begins when a reasonable being withdraws from the noise in order to find peace and order in his inner sanctuary. -- Peter Minard

...leaving a full 0.047" of thread engaged? I think not.

-- Not merely an absence of noise, Real Silence begins when a reasonable being withdraws from the noise in order to find peace and order in his inner sanctuary. -- Peter Minard