The Stovebolt Site Forums The Shop Area Engine Shop Cracked Block Repair

I have a crack along the lower left side of my 216 block. In previous threads, different ways of fixing it have been discussed. Deciding to go the easy way first, I tried JB Weld with no success. The crack just opened up right through the material. Then I bought a product from Eastwood called High Temp Epoxy (#31177). It is an aluminum-filled resin which comes with screen material to use as reinforcement. Have brought the engine up to operating temp a couple of times since with not a drop of water leaking out.

Hi pknauth,

Back when I was in high school, I took metal shop classes, and one of the projects that we did was weld a crack in cast iron engine block.

First we used a angle grinder to clean the crack before we started welding. Then just one "tack" (dot) at each end, then wait 10-15 mins when the cast iron is fully cool. We kept repeating this until the crack was fully sealed.

One thing about cast iron it doesn't like to get real hot when welding on it. If it gets to hot, the crack will take off, and get bigger.
Chevyboy62

I had a 216 with the same common problem. Looked more like the bottom of the water jacket has rusted through from the inside,a line of small weeping pinholes.Does it rust through and crack, or just corrosion?Or crack and then corrode?

Yeah, lots of them are cracked in this same location. I always assumed it froze (Colorado), but it is at the bottom of the water jacket where a lot of crud collects. I wonder if engines that spent their lives in warm climates had the same problem.

Odds are that if the truck lived south of the Mason-Dixon line where it didn't freeze that it didn't have antifreeze in it. When I was growing up most folks only added water in the summer, then come fall they would add enough anti-freeze to get through the winter. Now we know that anti-freeze prevents corrosion, I'm just old enough to remember the tail end of the use of alcohol for freeze protection.

I had a very similar crack in my 270. I took it to get machined and they "stiched" the block. It was a really neat operation.

They drill/tap holes along the crack, spacing them equally with a jig of sorts. they then tap each hole and screw a special screw into the holes. the head of the screw is designed to break off leaving a nub. They then drill out the space between each previously tapped and now filled hole. This drilling will overlap the new screws that were just installed. the new holes are tapped and new screws are installed in these holes. again the heads break off and all that is left to do is to grind down any excess that is left sticking out and you have a "stiched" block.

I was told that this is as strong as the original block due to some special threading of the screws that are installed. They actually pull the two pieces of metal together, or just close the gap caused by the crack.

The guy who did mine showed me how strong this system was by taking 2 pieces of flat stock and butting them up together. he then tapped a hole right down the butt line. Then screwed the special screws in and I could not pull the two peices apart. it was way cool!

Anyway, the process was not extremely expensive. I had my entire block rebuilt and the stiching done for $2200.00. i am not sure what the stiching costed, but I think it was less than $250.00.

Good luck.

Tom

yup bluebird, I've had that stitching done a time or two. Another approach is to drill the two ends of the crack and install screws and grind out the crack and fill it in. Had both ways done and both worked good for me.