Cracked Block

[Mike T.]

Just brought home a barn find and discovered the original block is cracked. Looks like it froze up. Horizontal cracks on both sides, just below the heads, each about 4 to 6 inches long.
We've heard that over the past few years some new processes have emerged that can save these blocks.
Has anyone had good experiences with "stitching," "lacing," or using a special kind of stick weld?
Thanks.

[Clem Z.]

Re: Cracked Block

Just brought home a barn find and discovered the original block is cracked. Looks like it froze up. Horizontal cracks on both sides, just below the heads, each about 4 to 6 inches long.
We've heard that over the past few years some new processes have emerged that can save these blocks.
Has anyone had good experiences with "stitching," "lacing," or using a special kind of stick weld?
Thanks.

i have had them welded with a high nickel rod and a lot have been
"stiched" i would have it pressure checked before doing any repairs to make sure there are not more cracks

[Clem Z.]

Re: Cracked Block

more info. http://www.lincolnelectric.com/knowl...ronpreheat.asp

[Domenic T.]

Re: Cracked Block

more info. http://www.lincolnelectric.com/knowl...ronpreheat.asp

Clem,
I found that interesting and now understand why some of my welds were good and why some were not so good.
By the way (Just a tid bit), I was getting ready to put the intake on a 350 that I painted with a doner intake and the guy watching said " are you going to put that on before fixing that crack"?
I got a cold feeling as I saw a 10" crack above the lifters. The shop that bored the block said they test every engine for leaks, they didn't.
I think your idea on the leak test is good especially if the cracks are internal.

DOM

[Mike M.]

Re: Cracked Block

make sure the weld shop heats the block in a furnace before using the nickle rod that clem mentions above.mike

[Clem Z.]

Re: Cracked Block

make sure the weld shop heats the block in a furnace before using the nickle rod that clem mentions above.mike

the guy that did mine use a charcoal pit to heat the blocks.

[Joe L.]

Re: Cracked Block

Just brought home a barn find and discovered the original block is cracked. Looks like it froze up. Horizontal cracks on both sides, just below the heads, each about 4 to 6 inches long.
We've heard that over the past few years some new processes have emerged that can save these blocks.
Has anyone had good experiences with "stitching," "lacing," or using a special kind of stick weld?
Thanks.

Mike------

If you are referring to a horizontal crack in the lifter valley, these are fairly common on small blocks. I'll bet a lot of guys have them and don't even know it. I highly recommend "stitching" as the method of choice to repair these. With a weld, it's tricky metallurgy and one never really knows what the quality of the weld is. You could end up with even more cracks adjoining the weld.

With a "stitch" there's not any "guesswork". However, a "stitch" is expensive because there's a lot of time involved in doing it, especially if the crack is long and/or there are multiple cracks.

[Clem Z.]

Re: Cracked Block

Mike------

If you are referring to a horizontal crack in the lifter valley, these are fairly common on small blocks. I'll bet a lot of guys have them and don't even know it. I highly recommend "stitching" as the method of choice to repair these. With a weld, it's tricky metallurgy and one never really knows what the quality of the weld is. You could end up with even more cracks adjoining the weld.

With a "stitch" there's not any "guesswork". However, a "stitch" is expensive because there's a lot of time involved in doing it, especially if the crack is long and/or there are multiple cracks.

most of the time "stiching" is done on expensive blocks like large diesels.

[John S.]

Re: Cracked Block

Just brought home a barn find and discovered the original block is cracked. Looks like it froze up. Horizontal cracks on both sides, just below the heads, each about 4 to 6 inches long.
We've heard that over the past few years some new processes have emerged that can save these blocks.
Has anyone had good experiences with "stitching," "lacing," or using a special kind of stick weld?
Thanks.

I had similar several (2"-3" long) horizontal cracks on the side of of my 72 350CI block just above the pan attach points. My intent was to save an original # matching block. The machine shop suggested that they be stitched rather than welding. He told me there is a risk of more cracking do to heat up and cool down of the welded area if it wasn't done correctly. So stitching was done and haven't had any problem as of yet. I might add that when done (if done correctly) it is almost undetectable to visual inspection.

John

[Clem Z.]

Re: Cracked Block

here is all you need to know about "stiching" http://www.locknstitch.com/

[Mike T.]

Re: Cracked Block

Thanks Joe and everybody. I'm headed in the right direction now, and know what questions to ask. There's a couple places here in Dallas that do stitching. One guy calls it "lacing."

[Jerry G.]

Re: Cracked Block

here is all you need to know about "stiching" http://www.locknstitch.com/

Very interesting. I see they do cylinder head repair. I happen to have a couple of 461 heads with cracks in the combustion chamber through the valve seat. It looks like they do this kind of repair. Has anyone ever done this repair with Chevy heads and how did it hold up?

[Peter J.]

Re: Cracked Block

Clem,
Thanks for the post, that explains stitching - something I have heard about but knew nothing of.

[Joe C.]

Re: Cracked Block

Here are the videos that I watched last year, before deciding that I'd weld a crack if I had one. The procedure is VERY labor intensive, and interesting to watch:

http://www.youtube.com/watch?v=Pq0wfU4ZaKk

The process is covered in THREE videos, first for pin installation, second for lock install, and finally, the thread repair.

Putting cast iron heads in a large gas grill with the cover closed will heat the part to 700 degrees before it can be braze welded. If the crack is drilled on each end, and then v-cut before filling with bronze, it should be fine. The cooling process must be done slowly.

[Rich G.]

Re: Cracked Block

That was a good video. I had a 36 ford flat head stitched with 100 pins and ran it for 5yrs without a problem. Just had a 440 done and unfortunately found out it was cracked by the motor mount after the whole car was done! No problems there either. I never saw the process done before. Gotta love the fact that there is a tool for every thing!