Posted by gordon maney, power wagon advertiser on May 30, 1999 at 21:45:28:
In Reply to: CRACKED BLOCK posted by JerRy on May 29, 1999 at 17:29:36:
If your crack is confined to accessible surfaces of the cylinder block, you can repair it with a system called Lock-n-Stitch. I learned of it during my time with Kwik-Way, manufacturer of automotive machine tools used by automotive machine shops.
The system uses an overlapping row of threaded, tapered studs. The head of the plugs twist off as they are screwed in with a pneumatic tool. The plug twists off at a reduced diameter part of the plug, just below the head. The reduced diameter is sized to permit the appropriate maximum driving torque for the diameter of the tapered thread. Pilot holes are drilled in the overlapping pattern with a drill jig. Then the holes are tapped. Subsequently, the plugs are screwed in. Pilot holes are drilled one at a time, drilling some of the previously installed plug away to make way for the next plug.
The completed row of installed plugs can be ground down, and the surface finished to make the repair virtually invisible.
It works really well, and it is quite a fast procedure. It was initially developed for industrial maintenance problems and found a logical home in the automotive industry. All things condsidered, it is a relatively cheap repair. It is very, very reliable. On a surface crack such as you describe, I would use this method before I would weld, even given the good history of success welding methods such as have been mentioned. There are also aluminum plugs for repairing aluminum castings.