3782870 Iron Alloy

[Patrick H.]

Re: 3782870 Iron Alloy

BTW 2: I thought Saginaw Cast Metals now uses the lost foam process in addition to sand casting for aluminum production. Where is Mark Gorney when we need him?

They sure did last year when you and I toured it.

[Cecil L.]

Re: 3782870 Iron Alloy

They may or may not, have higher nickle content, but there is nothing on the block casting that tells you this. The part number or casting number reflects the design and metallurgy.
As was pointed out, the 010 and 020 referred to are simply the last three digits of the casting numbers in production at that time that use the same front and rear end patterns . In this case it's 3970010 for the 350 and 3970020 for the 307 which were cast at Saginaw. If you look in the same place on a Tonawanda cast small block of the same period, you will find 014 and 024 which have nothing to do with the metallurgy but represent the last three digits of the 3970014 350 block and the 3970024 which is a 307. That's why you find 011 , 962, 068, 814, 422 etc in the same area on the front and back of 348's and 409s since they use the same end patterns.
.
Here's a response to a question about the "010/020 high nickle content block" myth from a thread on block castings on NastyZ28.com from a guy who actually works in the foundry:

"I work at a GM foundry. We make engine blocks, heads & cranks.

The numbers you are talking about (010, 020) are only sand core identification numbers. The 010 is a side core for a small block chevy, and it does not guarantee that the block is a 4 bolt or not. Most were 4 bolt blocks, but some 2 bolts were built with 010 side cores, or whatever side core was available. The 010 designation has nothing to do with metallurgy (nickel content)
Each time we make a batch of iron, a 10 ton crane will move across the metal staging area and pick up certain metals and dump them into the cupola. Each batch is done this way, and the irom metalurgy between each batch can differ slightly. Certain iron batches are made for certain parts and heated to certain degrees. The only true way to tell the nickel content is by part number. But that alone is only a guideline, and cannot be relied on 100%. Most high nickel blocks will also have a brighter sheen after a chemical cleaning. It would be the same sheen if a standard block was shotblasted 2-3 times.

Iron properties will differ from each run. Some will be harder due to longer mold line time, and some are slightly harder due to a multi travel through the shot peening booth.

But don't be fooled that harder iron is better. GreyIron (blocks, heads) under a microscope look like a slivered chip, whereas nodular iron (cranks, carriers) look like perfectly round balls. Grey iron that is hard will easily crack. Grey iron that is soft will easily wear. Nickel blocks are nice to have, but they will also be subject to mold line time. In the end, it'just a brag to a select few if you have a nickel block.

You need to understand how sand cores are created & assembled to have an idea of what I am talking about. The timing cover front slab core is a different sand core than the side slab cores or the rear slab core.

Each sand core has an identification number, so we can trace it back to the core number if there is a problem with the finished product. Because once the block has been poured, and mold line time has expired, the entire block mold goes through a shakeout process where the sand mold is destroyed and the iron block is extracted. Once this happens, all of the sand cores have been destroyed, and the numbers on each facet of the block is all we have left to trace identification.

Other identification areas are just inside the waterpump holes. You will see water jacket numbers there. You will also see numbers on the underside of the block, next to the first cam journal. This is the barrel core number. The large single digit number near the part number is the drag core pttern number. Alongside that, you might see CFD or GM-D, which means "central foundry Defiance, or GM-Defiance. SMCO means Saginaw metal casting operations.

Every facet of a block or head will have identification marks to tell me what particular core was used to create that particular part.

And as in your case, some cores are universal. Even all the big blocks & small blocks we make today use similar iron recipes. Some may have hotter iron batches such as the 3.8 cylinder head, but the ingredients are the same.... unless it's a bowtie run.

When we pour iron, the only reference to what we are making is the last 3 digits of the part number. "We're making 781's today!" We never refer to any other identification such as core numbers. The iron blend is purely based on the casting part number.

Think about going out to buy a GM block. Try and ask the parts guy that you want a part number "xxx", BUT with a 010 side core or a 020 front core. He will look at you strangely, and then laugh at you, because the differences are indexed by part numbers only, not by core numbers. His parts book is indexed by part numbers only as well. GM indexes all the differences with their parts by different part numbers.

Once all the cores are screwed together to make a core package, the package assemblies can sit on shelves for days before they are placed in the mold for an iron pour. And... once all the core pieces are screwed together to make a core package, there is no possible way for us to see inside to verify what core numbers were used to make the core package.... Because of this, we cannot follow the myth that 010 ID's mean "high nickel", because it's impossible to view the 010 ID once the package is screwed together & shelved. The only ID we have is the part number.

What you wrote was how it was supposed to be. But once it was put through the system, engineering realized that their intent could not be efficiently tracked. So the plan was abandoned, but it would have been too costly to rework all the patterns in the core machines, so those were left alone.

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.
BrianBerry"

[Kenneth B.]

Re: 3782870 Iron Alloy

They may or may not, have higher nickle content, but there is nothing on the block casting that tells you this. The part number or casting number reflects the design and metallurgy.
As was pointed out, the 010 and 020 referred to are simply the last three digits of the casting numbers in production at that time that use the same front and rear end patterns . In this case it's 3970010 for the 350 and 3970020 for the 307 which were cast at Saginaw. If you look in the same place on a Tonawanda cast small block of the same period, you will find 014 and 024 which have nothing to do with the metallurgy but represent the last three digits of the 3970014 350 block and the 3970024 which is a 307. That's why you find 011 , 962, 068, 814, 422 etc in the same area on the front and back of 348's and 409s since they use the same end patterns.
.
Here's a response to a question about the "010/020 high nickle content block" myth from a thread on block castings on NastyZ28.com from a guy who actually works in the foundry:

"I work at a GM foundry. We make engine blocks, heads & cranks.

The numbers you are talking about (010, 020) are only sand core identification numbers. The 010 is a side core for a small block chevy, and it does not guarantee that the block is a 4 bolt or not. Most were 4 bolt blocks, but some 2 bolts were built with 010 side cores, or whatever side core was available. The 010 designation has nothing to do with metallurgy (nickel content)
Each time we make a batch of iron, a 10 ton crane will move across the metal staging area and pick up certain metals and dump them into the cupola. Each batch is done this way, and the irom metalurgy between each batch can differ slightly. Certain iron batches are made for certain parts and heated to certain degrees. The only true way to tell the nickel content is by part number. But that alone is only a guideline, and cannot be relied on 100%. Most high nickel blocks will also have a brighter sheen after a chemical cleaning. It would be the same sheen if a standard block was shotblasted 2-3 times.

Iron properties will differ from each run. Some will be harder due to longer mold line time, and some are slightly harder due to a multi travel through the shot peening booth.

But don't be fooled that harder iron is better. GreyIron (blocks, heads) under a microscope look like a slivered chip, whereas nodular iron (cranks, carriers) look like perfectly round balls. Grey iron that is hard will easily crack. Grey iron that is soft will easily wear. Nickel blocks are nice to have, but they will also be subject to mold line time. In the end, it'just a brag to a select few if you have a nickel block.

You need to understand how sand cores are created & assembled to have an idea of what I am talking about. The timing cover front slab core is a different sand core than the side slab cores or the rear slab core.

Each sand core has an identification number, so we can trace it back to the core number if there is a problem with the finished product. Because once the block has been poured, and mold line time has expired, the entire block mold goes through a shakeout process where the sand mold is destroyed and the iron block is extracted. Once this happens, all of the sand cores have been destroyed, and the numbers on each facet of the block is all we have left to trace identification.

Other identification areas are just inside the waterpump holes. You will see water jacket numbers there. You will also see numbers on the underside of the block, next to the first cam journal. This is the barrel core number. The large single digit number near the part number is the drag core pttern number. Alongside that, you might see CFD or GM-D, which means "central foundry Defiance, or GM-Defiance. SMCO means Saginaw metal casting operations.

Every facet of a block or head will have identification marks to tell me what particular core was used to create that particular part.

And as in your case, some cores are universal. Even all the big blocks & small blocks we make today use similar iron recipes. Some may have hotter iron batches such as the 3.8 cylinder head, but the ingredients are the same.... unless it's a bowtie run.

When we pour iron, the only reference to what we are making is the last 3 digits of the part number. "We're making 781's today!" We never refer to any other identification such as core numbers. The iron blend is purely based on the casting part number.

Think about going out to buy a GM block. Try and ask the parts guy that you want a part number "xxx", BUT with a 010 side core or a 020 front core. He will look at you strangely, and then laugh at you, because the differences are indexed by part numbers only, not by core numbers. His parts book is indexed by part numbers only as well. GM indexes all the differences with their parts by different part numbers.

Once all the cores are screwed together to make a core package, the package assemblies can sit on shelves for days before they are placed in the mold for an iron pour. And... once all the core pieces are screwed together to make a core package, there is no possible way for us to see inside to verify what core numbers were used to make the core package.... Because of this, we cannot follow the myth that 010 ID's mean "high nickel", because it's impossible to view the 010 ID once the package is screwed together & shelved. The only ID we have is the part number.

What you wrote was how it was supposed to be. But once it was put through the system, engineering realized that their intent could not be efficiently tracked. So the plan was abandoned, but it would have been too costly to rework all the patterns in the core machines, so those were left alone.

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.
BrianBerry"

THANKS BRIAN
You gave a very good view of what it the foundy dose. I was patterenmaker starting in 1963. I worked at 2 pattern shops that had foundries & owned a 50 man shop since 1976. Funny that people think every casting is the same. People don't realize that you are pouring iron down a sand hole in a mold that has 15 to 20 cores. They don't know about core driers & core ovens.

[Peter L.]

Re: 3782870 Iron Alloy

I had no idea I would create this much discussion. I thank all who have posted contributions, especially the foundry man who gave a very detailed discussion of the casting process in a high production plant. I would like to add something. After reading all the threads (a hugh number), I decided to do some basic reseach on gray iron content. What I found confirms that casting pattern number conclusions, that the 010 and 020 have nothing to do with metalury, but only identify a particualr mold pattern part. Basically the research I did found that tin and nickel would never be added to iron in quantites over 2 to 3% maximum, to inprove strength. In fact, one of the references I found actualy does experiments of up to 5 or 6% nickel, but anything over 3% is the point of diminishing returns (the added cost in no way is justified by the very slight improvement in performance). So I have to conclude that the 010 and 020 that some refer to as tin/nickel content, is nothing more then urban legend. The fact to someone actually put in in a book doesn;t confirm it, the instead just means he bought into the legend. Check out the two references below. The first is a very technical paper on the effects of nickel when combined with other elements, on gray iron, . Being an ME, and having taken metalurgy a million years ago, I was able to follow the papers findings. Again, there is no mention of ever going above 3% nickel to improve strength. The second is much shorter, and re-inforces that conclusion.

http://www.nickelinstitute.org/~/Media/Files/TechnicalLiterature/NickelandGreyIron_InfluenceonStructureandProperties_310_.pdf

http://books.google.com/books?id=NbgtnLo7jhwC&pg=PA46&lpg=PA46&dq=nickel+and+tin+in+gray+iron&source=bl&ots=IjNbRf7N0G&sig=x6rQLtQyYW-WnCncsS86_mcWkBY&hl=en&sa=X&ei=1ENnUJ2aKaT00gH5gYGQDg&sqi=2&ved=0CB0Q6AEwAA#v=onepage&q=nickel%20and%20tin%20in%20gray%20iron&f=false

Again, thanks to all for the informative discussion.

[Kenneth B.]

Re: 3782870 Iron Alloy

I had no idea I would create this much discussion. I thank all who have posted contributions, especially the foundry man who gave a very detailed discussion of the casting process in a high production plant. I would like to add something. After reading all the threads (a hugh number), I decided to do some basic reseach on gray iron content. What I found confirms that casting pattern number conclusions, that the 010 and 020 have nothing to do with metalury, but only identify a particualr mold pattern part. Basically the research I did found that tin and nickel would never be added to iron in quantites over 2 to 3% maximum, to inprove strength. In fact, one of the references I found actualy does experiments of up to 5 or 6% nickel, but anything over 3% is the point of diminishing returns (the added cost in no way is justified by the very slight improvement in performance). So I have to conclude that the 010 and 020 that some refer to as tin/nickel content, is nothing more then urban legend. The fact to someone actually put in in a book doesn;t confirm it, the instead just means he bought into the legend. Check out the two references below. The first is a very technical paper on the effects of nickel when combined with other elements, on gray iron, . Being an ME, and having taken metalurgy a million years ago, I was able to follow the papers findings. Again, there is no mention of ever going above 3% nickel to improve strength. The second is much shorter, and re-inforces that conclusion.

http://www.nickelinstitute.org/~/Media/Files/TechnicalLiterature/NickelandGreyIron_InfluenceonStructureandProperties_310_.pdf

http://books.google.com/books?id=NbgtnLo7jhwC&pg=PA46&lpg=PA46&dq=nickel+and+tin+in+gray+iron&source=bl&ots=IjNbRf7N0G&sig=x6rQLtQyYW-WnCncsS86_mcWkBY&hl=en&sa=X&ei=1ENnUJ2aKaT00gH5gYGQDg&sqi=2&ved=0CB0Q6AEwAA#v=onepage&q=nickel%20and%20tin%20in%20gray%20iron&f=false

Again, thanks to all for the informative discussion.

THANKS for doing the search. If there was 20% nickel you couldn't machine the casting. Remember the people machining the castings did not want to machine hard iron or iron that has hard spots.

[Bill M.]

Re: 3782870 Iron Alloy

If there was 20% nickel you couldn't machine the casting. Remember the people machining the castings did not want to machine hard iron or iron that has hard spots.

That is how we discovered that the casting supplier had added the wrong alloy to our cast iron castings. The company that machined them noticed there was a problem. Since the part was a safety item, that kicked off an engineering investigation to determine if a recall was necessary. We got lucky, no recall required.

[Kenneth B.]

Re: 3782870 Iron Alloy

That is how we discovered that the casting supplier had added the wrong alloy to our cast iron castings. The company that machined them noticed there was a problem. Since the part was a safety item, that kicked off an engineering investigation to determine if a recall was necessary. We got lucky, no recall required.

All castings had to be in certan hardness range. At the foundry every batch of iron that is poured a few castings wre Brenell hardness teasted. Sometimes there is a screw up. Castings can be too soft as well as too hard like the 3 bears porage.