BB65

Is it possible to repair a cracked block to a level where it will pass NCRS judging? If so, then does anybody have a recommendation?

365GTB4

Back in 1980 I had my block welded. The block had frozen and the area on the side of the block had pushed out and cracked. The process was cut out the cracked area and weld it back in. This is tricky because the cast iron is hard to weld and the block had to be annealed in an oven. Then the whole area was braised over to ensure no leaks. Then the area was sand blasted. It is hard to tell that the block has been welded. The down side is the block was warped and had to be line bored and decked which wiped out the original stamped numbers. In 1980 it cost about $2000.00 and took a couple of weeks.

I know the antique guys do this all the time on valuable old blocks but I would think you could find a replacement block that would be suitable if you look long enough.

magicv8

Yes - and what you end up with depends on what's cracked. I have seen an NCRS article or two on the subject, which is why old cars with original engines don't mean much to me. Driving one long distances could "expose" a repair.

jdk971

over at 348-409 site, several cracked blocks have been stitch welded. but as mentioned
above it depends where the crack is. jim

BB65

Thanks for the info --- I will look at the NCRS articles. I prefer saving the block -- it's a 396 -- and I avoid a "re stamp". The cracks are all on the water jacket -- no cracks elsewhere. I have a second block that will be "the runner". The first one is for judging only.

Nowhere Man

if it is only going to be driven on and off a trailer and onto the show field it can be done.

MikeM

It is still a mystery where your block is cracked, believe it or not.

Don't use brass in the repair as paint doesn't like to stick to it. The stitch welding is drilling/tapping/plugging and works well.

BB65

To be more specific about location, the crack is horizontal, about 1" below the deck, about 12" long. Ordinarily, the exhaust manifold would hide most of the crack. I have not pulled the soft plugs, nor boiled it out. The prior owner repaired the crack with some sort of grey epoxy. I have read about stitching --- but it seems that method would not pass visual muster with a judge.

MikeM

If that judge has a three axis periscope, he might be able to see the repair. Not that he has any business inspecting that area.

If your block is cracked there, it may be cracked on the inside above the lifters also.

The Lock Stitch method is easy to disguise.

BB65

The block is not cracked anywhere else that I can see --- it has been completely dismantled and inspected. No cracks at the bores or the lifter valley. If the stitching can be disguised, then it makes sense to me too --- avoids ovens and high heat altogether. That all said, I have heard some judging stories that seem to rise to the level of "stranger than fiction". And maybe that's what they are: fiction.

67*427

Want to see what a GOOD stitching company can do??? Here's the link to my 427 that was repaired. You can't find the repair now and if you go to their website, you can see some of the work they do. They do ALL of the work for the Nethercutt Museum in LA and many of their cars are national award winners.

If you want to call them, ask for Gary and tell him I told you to call. They'll treat you right.

http://www.dasplace.net/Corvette/Loc...-N-Stitch.html

Steve

mgoeppert

Do a search for Lock N Stitch in Turlock, CA.

BB65

Thanks you guys --- I will look into the stitching.

pullin-gs

This is a scary thread....makes me never want to purchase a restored matching numbers vette again!

65specialk

What is there cost to do a repair??
Dave

John McGraw

I have had several blocks repaired over the years and have never had one leak. I have an old guy in Austin that has done them for me and you can not see the repair once it is done and painted. They drill on either side of the crack and drive tapered plugs into the holes to close up the crack. They put a sealant in the crack before driving the plugs in. This is commonly known as "stitching" a crack, since the holes alternate to opposite sides of the crack. He grinds off the remaining plugs and re-textures the block with a needle scaler, and it looks like virgin cast iron.

Most of the guys that do this are real artists, but they are getting old and quickly disappearing.


Regards, John McGraw

BB65

John --- Is this guy still around? If so, do you have a name?

Mike

landshark 454

There used to be a place in the Carolinas that did both cast iron, and aluminum block and head repairs and guaranteed the repair to be undetectable. Their brochure showed repairs to devastated parts, not just cracks, but blocks that you could stick your arm through, and they had a $10,000.00 bond that they would pay if you could detect the repair. My friend had a pair of L88 heads repaired. They came back perfect. They could also return modified parts to original configuration, with original finish.

I also saw a display at the Atlantic City Auction for a company that did the same thing. They displayed a V 24 small block that they had put together, complete with finned valve covers. It looked like one solid casting. They were located in New Jersey.

This was over 15 years ago, but shows that the ability exists.

magicv8

I've known that there are people doing this for the last 20 years. While I would buy a Corvette with an original engine, I would not pay a premium to get it, unless all I intended to do was drive it between the trailer and the show field to collect awards for my own edification.

MikeM