MTFCA Forum

I decided to try the Lock-n-Stitch method to repair a freeze crack in a 1918 block. This crack was an easy fix as the parent material was thick enough to catch plenty of threads on the pins. Here are the before and after pics. I still have to grind the heads of the pins down to the surface of the block and use a de-scaler to reintroduce the original casting texture look. Next will be the usual cracks on the underside of the water jacket. The block wall is often thinner there and trying to drill and tap a hole perpendicular to the crack won’t be easy due to the limited access area for the drill. Rich C.

No cracks in the "pass through" between #2 & #3 I hope?

Rich: They make an drill and tap extensions that will help you there. But you are right that blocks are thin at that crack. Dan

Jerry- my experience has been that you almost always see the valve chamber crack in the 26-27 blocks and not the earlier ones. Anyone?

Dan McEachern wrote: ↑

Wed Jan 27, 2021 4:42 pm

Jerry- my experience has been that you almost always see the valve chamber crack in the 26-27 blocks and not the earlier ones. Anyone?

It depends on how hot the engine got as the valve seat cracks towards the exhaust manifold not towards the cylinder.
It happens on all of them and not just a particular year.
These pictures are from a 1923 that we rebuilt. You can see the cracks towards manifold.

Sorry- I was referring to the crack that runs from the center core plug under the water jacket and into the valve chamber. Not sure I ever worried about one from the center water passage to the head bolt hole. Yup- the cracks toward the manifold are common in all blocks.

Good job! They way I was shown to do it is; install cut peen then do the next one. Also use a sealant on the pins before installing.