350 block 10066036, is this a high nickel block?
02-13-2013, 10:56 AM
#61
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When engineering originally developed the plan, they needed a way to identify the metallurgy after the block was poured, thus the fabled "stamp" But engineering soon realized that the same block part number could posess one of 3 different mettalurgical blends. Because of this, it was near impossible to trace or efficiently logistically locate castings from pourtime to end customer use, as well as service parts orders.
So it was abandoned, because with the original idea, you wouldn't be able to call any GM parts office & locate a "nickel 010 block", because there was not a specific part number associated with it. Parts are organized by part numbers, not core stamps.
Now, to straighten this out, they did change the casting part number to correspond with the metallurgical content. This is true for only older blocks (pre 71) Blocks after that just used the same sand cores as the older ones until pattern changes were made, which will give false hope to many.
Hinging on that, many cores were interchangeable. Today, error proofing measures have been installed, and it is impossible to assemble mismatched pieces without destroying a section of the core.
Processes were brutal years ago, and it was very common to grab the pallet of cores with the 010,020 stamps to keep the mold line running (even though the current run was not supposed to have the 010,020 stamps. The wost thing we could do, was to stop a mold line. If we did, the iron would cool, and we could freeze up the system with solidified iron. Always keep the mold line running! So, you cannot base your "nickel" block, solely on the 010 stamp on the timing face. Desperate times call for desperate measures, and cores have been switched in the past.
Today, most owners do not understand that the 010 on the side of the block has nothing to do what the metallurgical content is, or if it's a 4 bolt main.
Like I mentioned before, we have poured iron to what the part number is, not what the core stamps say. If I had 2 assembled core packages next to each other, you would not be able to tell if one had 010 on it, unless you destroyed & dissected it or poured iron into it & removed the iron to see. The one thing that is consistently 100% validated is the part number, which is part of the drag mold and is the seat for the upside down core package to rest in, before the cope is placed on the mold package, sealing it off.
In the end, if you have a 60's block with these stamps, there is a 95% chance that it is what you think it is. But it can be your luck that the 5% of mismatched core packages could be one of yours. If you have a 70's & up block, don't count on it, unless it's a bowtie (but only some bowties had different metallurgical qualities)
Hope that helps explain it.
So it was abandoned, because with the original idea, you wouldn't be able to call any GM parts office & locate a "nickel 010 block", because there was not a specific part number associated with it. Parts are organized by part numbers, not core stamps.
Now, to straighten this out, they did change the casting part number to correspond with the metallurgical content. This is true for only older blocks (pre 71) Blocks after that just used the same sand cores as the older ones until pattern changes were made, which will give false hope to many.
Hinging on that, many cores were interchangeable. Today, error proofing measures have been installed, and it is impossible to assemble mismatched pieces without destroying a section of the core.
Processes were brutal years ago, and it was very common to grab the pallet of cores with the 010,020 stamps to keep the mold line running (even though the current run was not supposed to have the 010,020 stamps. The wost thing we could do, was to stop a mold line. If we did, the iron would cool, and we could freeze up the system with solidified iron. Always keep the mold line running! So, you cannot base your "nickel" block, solely on the 010 stamp on the timing face. Desperate times call for desperate measures, and cores have been switched in the past.
Today, most owners do not understand that the 010 on the side of the block has nothing to do what the metallurgical content is, or if it's a 4 bolt main.
Like I mentioned before, we have poured iron to what the part number is, not what the core stamps say. If I had 2 assembled core packages next to each other, you would not be able to tell if one had 010 on it, unless you destroyed & dissected it or poured iron into it & removed the iron to see. The one thing that is consistently 100% validated is the part number, which is part of the drag mold and is the seat for the upside down core package to rest in, before the cope is placed on the mold package, sealing it off.
In the end, if you have a 60's block with these stamps, there is a 95% chance that it is what you think it is. But it can be your luck that the 5% of mismatched core packages could be one of yours. If you have a 70's & up block, don't count on it, unless it's a bowtie (but only some bowties had different metallurgical qualities)
Hope that helps explain it.
02-13-2013, 12:03 PM
#62
• Small block Chevy high nickel myth busted! I work in a materials lab for an aerospace company. I removed a chip from a mold seam line and performed an SEM/EDS analysis on my 3970010 010, 020, 509 block and discovered that it contains no measureable nickel or tin. This entire high nickel block legend is a hoax. Instrumentation is capable of detecting element concentrations as low as 0.1%.
Lets summarize
casting numbers:
3970010
3790020
3951509
numbers under the timing chain cover
010
020
509
Hmmmmm. OK, I've changed my mind. The 010 020 marking are indeed high nickel tin blocks and the 509 was Duntov's password for his laptop cause he kept forgetting it.
