Cracked block, cast iron.

[caferacermike]

Has this been beaten to death before? Sorry I typically stay over in my Mitsu/Satoh forum.

My lil Beaver got laid up over the winter months without much antifreeze in the mix and sure enough she popped. I basically bought a tractor to play with and gave it to a friend of mine to use on his land. Maintenance is his responsibility but he failed this time.

So what I have (at least I hope is the extent of the damage) is a block that has 2 cracks each about 3" long between the cylinders in the outside water jacket. Why the freeze plug failed to pop is another issue.

Research says strip the engine bare and either take it somewhere or pin stitch it. I may just pin stitch it but I'm afraid of drilling through the cylinders and making a bigger mess. I don't want to strip the engine as parts are as rare as hens teeth and I don't want to need gaskets, rings or bearings to go back together again.

I've been watching a few how to's and asking around a bit. I'm handy with the MIG and I can burn a rod if I have to. I don't know anything about stick welding other than crank up the heat until the rod melts. Lol. I have no idea what rod is what, just grab a grey one and go. I've got a nice 220v 180amp MIG and one method I've been interested in is swapping to a 307 stainless wire and basically making a 1/4" tack weld. Set down the torch and beat the snot out of the tack with a ball peen hammer and go do something else for 30 minutes. Allow the metal to completely cool and do it again, and repeat for days until finally closing up the crack.

I could also scrub the cracks clean, acid flux them, and brass braze them. Or I've considered some rods from Castaloy that claim to repair cast iron with a MAPP torch.

So what I'm asking is how would you do this considering that I feel stripping the engine, heating the case for a day, welding it and then cooling it for 2 days is out of the question. I could always Use JB WELD on them.

 

[puckgrinder85]

Are you absolutely sure that's the only cracks present?

Also freeze plugs aren't there to protect your engine from cracking from being frozen, yes they may pop out if it freezes but that's not their purpose at all and is just coincidence as they are the weak link. The holes they cover are just for sand cast removal.

 

[Arc weld]

Find someone with experience! Peening isn't beating the snot out of things. That will cause will cause more stress. 307 stainless? See if there any shops that specialize in cast iron repair in your area.

 

[caferacermike]

The tractor starts and runs fine for 10 minutes until it begins to overheat. Just ask my friend after I told him to check the water and oil levels before starting the tractor. Oops.

It's a diesel. I'm willing to bet it wouldn't have started easily if the cylinders were cracked.


Of course I really don't care either way. I'm totally willing to blow through some wire just to play.

Then again I'll be doing a complete compression test and leak down test once I get the tractor back to my home/shop.

But then again that's not what I asked about. I'd like to keep it on topic about how to weld this pig.

 

[caferacermike]

ARC, I did call around. All the shops said it must be totally stripped and bare. Again not an option. Once I strip it bare, I'll make more money selling the internals in my forum area than the tractor is worth as a running deal. It's just that I beat and beat and beat on our little grass mower and we'd like to keep it running just for novelty sakes at this point.


I mean, ****, I could just buy a running tractor. We just use it to mow down 30 acres. Nothing more than that.

And yes when I say grab a ball peen and beat the shart out of it, I'm just being an ***. It's called trying to be somewhat good humored about the fact that a friend killed my favorite Beaver.

I'm not going to strip the motor. That's a $2,000 option for a $1,200 tractor. There just are no longer any parts available for non-collectible tractor. What I'm after is a one time chance, just a shot at a repair before I pull the reverser and sell it along with the shredder and a few other parts and I retire it to the SouthEast corner and it becomes our shooting tractor.

 

[Arc weld]

Drill holes in the end of each crack, V it out a bit and run short MIG welds on it. It sounds like you don't really care and I've heard of people having success just MIG welding engine blocks cold.

 

[Mark @ Everlast]

I'd just have it brazed....shouldn't be a big issue...and probably the easiest way to fix it.

 

[Shield Arc]

This may help you, I've never done it myself. But I saved this from another site.

"I do a lot of cast iron repairs with 100% success so far. Last year, after several months of research, I found information on a couple websites & mostly in an old Lincoln Welding book. The process is called "Cold Welding Cast Iron With MIG". I practiced several weeks on broken cast iron parts & broken/cracked manifolds my bro' gave me to get my technique down pat. It has worked with superb results.

I use MIG, 309/309L .030 wire, 98/2(AR/CO2) @15cfh & generally in the 80A range. You can use any gas with a mix of no more than 5% CO2 (ex:95/5). The 309 wire has a carbon content of .01 & works best. The idea is to keep the temperature cool by running short beads <1" & allowing the joint to cool before continuing. After running the short bead, you can take your glove off & lay your hand on the metal & will feel only warm to the touch. Since your pieces are not large, I would suggest shorter 1/2" beads & allow each weld to cool back to room temp before continuing".

 

[yomax4]

Also look at Spray Powder for cast. never lets you down. I agree with the cold weld process if you are going to weld it. spray powder is always my 1st choice if the application is right.
. Drill and vee is a must too.

 

[flusher]

The lower right flange on the engine block of my 1947 Farmall Cub broke completely off. It's part of the attachment for the front end bolster that carries the axle and radiator. It's a known weak spot on that engine block and very often you'll find one cracked and sometimes completely broken like mine.

I was able to stick weld it with a stainless steel filler rod (Super Missile Rod, 1/8" dia rod, 90 amps, DC+). You need to control the temperature of the heat affected zone (HAZ) carefully to prevent cracks in the cast iron.

I don't have an oven large enough to heat the block to 1000-1200F as recommended for welding cast iron. So I used the alternative method--run short beads (1" long) and lay down successive beads using back stepping. I used an inexpensive infrared temperature measurement gun. Kept the peak temperature at or below 300F and let the parts cool to around 100F before running the next bead.

I peened the welds during cool down. I used an air chisel with a blunt rounded point initially. This seemed overkill so I changed to my pneumatic needle scaler to peen the beads. Seemed to work OK--no cracks in the welds or the cast iron.

It took probably 6 hours of work with a die grinder and steel burrs to bevel the edges and otherwise prepare the parts for welding. Had to rig up a fixture to keep the parts aligned during the welding process. The welding itself took about 4 days--I worked slowly and spent a lot of that time waiting for the parts to cool down and grinding the beads between runs. Now that I've done the job once, I probably could do it in half the time.

Good luck.