Welding steel to cast iron head?

Coming from an era when the repair, or attempted repair, of cracked engine block and heads was common, I'd advise using caution in attempting to braze an engine head as it can result in further cracks. Companies that were most successful used an oven to preheat the head/block and IIRC got it hot enough that the oil, which was soaked into the cast iron, burned out. Usually quite a long preheat also, maybe 6 - 8 hours. After welding or brazing a post heat was done for about the same time. All this cost a fair sum, in those days and alternate methods were devised to repair cracked engines.

One method was to drill and tapered holes (pipe tap) to fill the crack. Each hole overlapped the previously installed plug. Cheaper and often times successful.

There were also methods which called for grinding the cracked area clean and coating with some sort of cement which was also occasionally successful.

All in all, not a trivial sort of repair.

Having said all that I have seen a Chrysler V-8 head TIG welded. A crack that ran from valve pocket to valve pocket. The weld was successful.

Cheers,

John D. Slocomb (jdslocombatgmail)

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.

If it's just to mount a block on a castiron base, I'd drill four holes; two for dowels to keep the block from shifting, two tapped for small screws to keep the block from lifting off. Or, some kinds of rivet might be good (the expands-at-bottom type like for blind holes in concrete). Then I'd butter the holes and mating surface with RTV silicone and mist it with water (to start it curing) and screw the block down.

Preheat for brazing in cast iron is a nuisance. Takes hours.

I snagged a single stick of Evadour? Silicon Bronze today down in LA. Couple old 'uns who run two different welding shops were in my favorite welding distributor (Sims-Orange, Santa Ana) and thats what they suggested, using tig.

Ill do it this evening and report tonight.

Thanks all

Gunner, just back from 3 days in LA

I am the Sword of my Family and the Shield of my Nation. If sent, I will crush everything you have built, burn everything you love, and kill every one of you. (Hebrew quote)

I welded pipe flanges for 1" black iron pipe - the large flat with screw holes.

I stick welded them in the middle of A36 HRS plates used as stands.

Chinese flanges tend to flatten out and slump.

American flanges hold up nicely to stick and I welded through each hole.

Put on the 6' pipe and tried to tip it off the plate - it was on there. I figured it would hold a string of Helium filled balloons.

It was a Ni stick - black flux - have some in the shop still. Paid hazmat!!! Ni is a material that some people become sensitive to.

Mart> >