1. Repairing a crack across the exhaust valve seat on a 2.5L GM cylinder head.
CYLINDER HEAD & CASTING REPAIR
2. This is a common crack that extends across the induction hardened seat.
3. The method I use is the LOCK-N-STITCH metal stitching process. It is is approved by GM and several other manufactures. The crack is drilled and tapped and pins are installed in an overlapping fashion.
4. The repair is then ground down to the parent metal.
5. Peening the repair finishes it and relieves any stress the casting may have. The head is then pressure tested at 40 psi to be sure there are no leaks.
6. The valve seat is then cut to the proper size or a new seat is installed.
Soren Specialties, Inc
1-435-257-6140
1-800-950-2437
Repair on a 2.5L GM cylinder head
Repair of casting on a Quad 4 engine
The connecting rod on this Quad 4 engine caused the damage shown in the top photo. The missing pieces were left on the road.
Welding may be possible, but because of the location and the way cast iron behaves, the best way will be to use the LOCK-N-STITCH metal stitching process.
The process starts by making a plug for the break-outs from mild steel. Since the block is curved at the large break-out, the plug is made of thick material so it can be shaped to the contour of the block (Block is sprayed red to emphasize the plug).
The plug is epoxyed in place to start the stitching process. We begin by grinding the contour and using 6 stitching pins in three opposing spots. The LOCK-N-STITCH pins are used in an interlocking fashion until the plug is completely sealed to the base metal. The repair is then ground and peened to finish and contour the repair.
Inside view of stitching pins
Metal Plug
Damage
.
Finished repair
For more information on the LOCK-N-STITCH metal stitching process visit their website
LOCK-N-STITCH is a registered trademark of LOCK-N-STITCH, Inc.
116 N. 200 W. Tremonton, Utah 84337
