Cronatron welding products makes a superb welding rod alloy just for gears and shafts, they also have some great welding rods for cast iron have given me the best luck welding all types off metals

What will we do when all the arts of craftsman's are lost?

Have not been able to find any one local that still has an oven or furnace to heat and cool for welding.

Wife will not let me use her ceramics kiln:confused:
She said the head is to big to fit.

I don't really feel like building a bonfire to weld it in.
Wouldn't want to add to global warming;)


Have found a good bare head!!
Keep in mind I am not a diesel guy.
Was planing on using my old valves but find something that to me is odd.

The stems are good--little to no wear.

QUESTION
The seat area on the valve has a step back up to the thicker section.
Is this normal?
Or is this wear from the hard seats?

If it is normal then they will be a pain to grind but can do it.
If it is wear it is the worst case I have ever seen.

I suspect I will be buying new valves.

---

Talking about cast iron welding.
Have done automotive heads--mainly British and hard to find types.
A fish fry burner to pre heat and keep hot for welding/brazing.
All I have done was brazed.
When done would turn burner down slowly and sit close and listen.
If it didn't make the "pink" noise it probably didn't crack during cooling.
If it made the noise it cracked.
This is more doable than you would think.

Anyone ever mess around with oil surface hardening?
I have and it also works out way better than I would have thought.
Makes for an ugly surface finish!


Road trip to pick up head tomorow.
Hope its a good one.

Thanks
David

Cast iron welding rod for oxy-acetylene is still available, it's just hard to find sometimes. Try your local welding supply house, not a parts house as most times they don't have a clue for specialty stuff like this. If the welding supply house doesn't stock it, they should be able to order it.

Welding cast iron is somewhat of a lost art but it's not impossible as it's still just fusion welding. I used to drill the ends of the cracks out, then "vee" 'em out. Lots of preheat, constant heat during welding and a long slow cooling in wood ashes, lime or sand seems to work best.

I've had numerous cracked D6 heads repaired, using the "fusion" welding process. We had a great, local, cast-iron head fixing man for many years, but he retired, and I think it's a lost art.
He used to repair all the big diesel loco heads, that cracked in the extreme heat on the iron-ore railways of the North of Western Australia .. and he said they were his cream jobs, and all the others were just skim milk ..

He would fab a temporary furnace around the head, out of firebricks, with the head sitting on bricks on the shop floor, and then poke the gas burner in one side, and light it up. After a couple of hours, the head would be glowing a dull red all over, and he'd produce his cast iron rods (he made his own), and proceed to fusion weld the crack/s.

After welding, he'd gradually turn the gas down over a period of hours, then bury the head in sand for final cooling. His repairs were guaranteed, and I never had one of his welds crack .. and he did quite a number of repairs for me on the D6 heads.

At the time (late 1960's - early 1970's) .. a new head was around $AU2500, and the average crack repair cost was around AU$1000 .. so it was economic.
However, nowadays .. with aftermarket heads being low cost .. I would imagine that no-one even bothers to repair the old heads anymore.

My service manual arrived today and I now have a couple more questions.

Is it really necessary to pull the radiator in order to remove the crankshaft pulley? It looks like there are two small bolts (capscrews), and one large bolt (called a screw in the manual), then use a puller to get the pulley off. I'm hoping I can use a puller through the opening at the bottom of the radiator where the front pto would normally be. The service manual is describing removal of the timing gear cover but I'm content with stopping at the pulley. From what I've seen so far, I think there should be enough clearance to pull the pulley out without hitting the radiator.

When I spoke to a local welding shop about building up the pulley and then machining down to fit a "C" V-belt, he wasn't real keen about trying to build up on a cast iron pulley. I assume it is cast. Is this really going to be a problem or should I just try a different shop? Clearly CR was able to build his up with good success.

You guys are seldom wrong, and my parts book doesn't show them either, but Dean Cat and others show the valve seats are replaceable. The part numbers are 7F8922 for the exhaust valve seat and 7F8923 for the intake valve seat.

You can pretty clearly see a ring aroung the valve seat inserts in the head and when I lay my new inserts on top of them they line up.

I have tried TIG welding a bead around the insert to shrink it and have ground down a valve and welded it to the insert. The insert is really hard compared to the cast iron head around it and it just breaks chunks out of the insert when you try to drive it out with the valve welded to it. I even built a heavy duty "valve surrogate" with a 3/4 inch steel shaft that I TIG welded to the insert with stainless steel rod (seems to stick better) but this still won't drive the insert out.

If I had a mill I could reference it to the center of the valve guide and use an end mill to cut the old insert just shy of the exact depth and width of the new inserts I have. I am sure that it would then be weak enough to drive out.

Any other ideas would be appreciated.

Thanks,
KansasD7

Find the ends of the crack and drill a 1/8" or so hole just beyond where the crack starts. .this will keep the crack from "running" further. If you don't do this, there's a good chance the crack will continue to spread specially in something that the temp will vary.

Most times I'll use Ni Rod 66 but when there's a "problem" weld, I'll grind out what I've welded and switch to the Ni Rod 99. Preheat to 450 F or so, short welds, peening after each inch long weld and bury the part in lime or ashes works well. Let it cool totally. .for a day or so before digging the part out.

Back "in the day" cast iron used to be gas welded with actual cast iron rod. This meant the part was heated to a dull red then fusion welded. After welding it was buried in again, either lime or ashes and left for several days depending on how big it was.

The D7 head that developed porosity for me was cracked before I got the machine. I had both heads welded. One worked out fine. The other was porous after the welding.

Cast iron is unique stuff. It is iron, of course, with graphite interspersed throughout. The graphite is not alloyed with the iron as with carbon steel, but exists as carbon particles. When the iron is heated too hot for too long, the graphite can be burned out of the iron and the casting loses a lot of it's desirable charistics, among them the ability to hold water.

By same token, hot iron cooled in water quickly removes the carbon from uniform dispersion in the iron and the result is "chilled" or "white" cast which is brittle as glass and hard as a whore's heart. it was used for years in plow bottoms and they would wear forever.

Quick and not the best course in metalurgy, it is the best I can do without going back to my old text books. Hope I have helped you get a rough idea of the problems associated with heating/cooling cast.

The people who reweld antique cast iron stoves, or the shops that weld cylinder heads and manifolds can fix that. You want to find a shop the uses preheating and post heating ovens. They also have to use gas welding and cast iron rod. You can use a high nickel arc rod on a modern head but on an old manifold the gas / cast iron rod will last better. Exhaust manifolds do not heat or cool evenly and the differential expansion will break the weld if it is not cast iron.

As a semi disinterested observer here, as I neither own a D2 nor have even handled one of the offending prechamberers I could be all wrong.

Now, having the disclaimer out of the way. I would think there are only two viable means of removal. It should be possible to disassemble the chamber and punch out the broken stub. Disassembly will require making two fixtures to hold both the top and bottom half of the chamber while it is heated to the point the brazing material liquefies. These fixtures would have to be made of cast iron to prevent inadvertent welding to the chamber.

The second would be to shape a common cold chisel to fit into the bore and use it like a star drill to slowly chop the broken glow plug tip to small enough pieces to allow picking out of the chamber. Lots of tap and turn of the chisel followed by picking small pieces should do it.

From the looks of the crack, it IS in a pretty critical spot. From what I see the bracket the is cracked is a front support for the engine and and harder you work the rig the more this crack could be a problem. Research you area and the welders and find one that is well experienced in cast iron welding as cast is a very picky metal to weld. Experience will determine the difference of the weld lasting the life of the rig vs rebreaking in another spot close to this one.
MIke

some of the spokes are cracked and welded ,I know today the welding on cast-iron is a little better

Set both idlers on wooden blocks side by side in front of you holding them off the floor enough to let them turn freely. Lay one pass on one, move the ground to the other idler, lay one pass on that one. keep doing that . It will give the iron time to cool. Also alternate sides of the idler in this system, (Outside of one, then outside of the other, then inside of the first one and then inside of the second, and so on. Set a fan up to the right or leaft of you to keep the air moving across the idlers. It only has to be a 20 inch window fan and it doesn't have to be trying to blow you over. It does two things. Helps cool.(Yes minimally, but it helps) and it blows the noxious gas smoke away from you as you weld. Doing it this way gives the iron time to cool and then you don't need to worry so much about cracking. Cracking may be more the result of the rod than anything. Different rods pull and shrink differently. Check with your welding supplier and tell them you are welding on cast steel that has been case hardened and that the idler has worn through the hard part. The best hard rods I have ever used were called Rainite (I have no idea anymore if it's even made becasue se used that a long time ago) and the NAPA rod I told you about earlier

Hope that helps

Chris

First you gotta realize that the gasoline we get today is absolutely awful in a cast iron engine that tends to be slow warming up. If there is anything, and I mean ANYTHING, even slightly wrong with fuel system or ignition there's going to be problems. Just do all the obvious stuff first--fuel supply, carburetor clean, magneto up to specs, clean spark plugs, etc.

If you need to clean plugs as often as I have, try heating them with a propane torch--acetylene won't work, too much carbon--and trickle in a little oxygen from the welding torch while they are red hot. The carbon will burn like fourth-of-July fireworks clear up to the seal. It's a poor substitute for new plugs but it's affordable. (Check them carefully. Occasionally a porcelain will crack.)

I run John Deeres that were built to burn stove oil and they have problems with our present day gas if there is anything just one click away from perfect.

Good luck.

Jack

I have scene that there has been some problems with getting some pieces repaired and getting the correct ones back, We are doing the same process in Connecticut and will do repairs to heads, manifolds, jugs and blocks etc. We also do welding and fabrication of unique pieces and restorations. For more information call 860-213-1771