Nickel in blocks???
 

Saw this on FB.. varying replies as if it is an urban legend.

Anyone know the real deal?

One of the CRG Core members asked the same question years ago. The late John Z's response:

NOPE.

"Most people have no clue how a high-volume foundry operates - the "recipe" for the grey iron and malleable iron melt load wasn't changed; it was very carefully arrived at over the years, and its content was stabilized. The "high-nickel block" theory was debunked years ago, although some folks still cling to it."

John

Very interesting, I've always heard about the 010 block being high nickel too.
So, does anyone know what the 010, 020 509 indicate on a block ?

Last three digits of the part number, the block applies to 3 variants on this one.

Well this can be tested. Get a 307 casting and drill into it and you will see how soft the casting is compared to the same year 010 302/350.

Start there.

Casting numbers are different due to changes in metallurgical content and design.

This makes sense…..and what I assumed for years.

3970010
3970020
3951509

Kurt

Yep. and why the need for variants??

Nearly all 010 castings from the mid 1970's onward were all "010" for all HP designations. Why were there basically no variants after hi compression was dropped?

Better yet just have a metal composition analysis preformed, it will tell you all you need to know about the high nickel block, after all they did cast the harder ductile main bearing caps. So the material was there.my .002 cents.

Recall all those kids that did budget builds on 307's by overhauling them with higher compression pistons?

Neither do I.

I'm a metallurgist and was superintendent of the melt department at the Tonawanda metal casting plant. Jon's statement was true. We ran all 4 of our cupolas with the same chemistry base iron. We were producing about 2,500 tons of iron a day - feeding 7 molding lines, so as a practical matter, it would have been impossible to route different base irons to different lines in production. Alloying with ferro-chromium and silicon was performed as the iron was poured into the hot metal crane ladles (these cranes traveled on monorails that transported the molten iron to the individual molding lines). All lines received silicon (a late alloying agent designed to refine the grain structure of the cast iron by providing more grain nucleation sites and reducing carbide formation). Ferro-chromium was only alloyed into the lines that produced blocks (mold line 1 & 2 at Tonawanda). It was added to promote pearlite formation which increased the tensile strength of the cast iron. You may ask - then why wasn't ferro-chromium added to metal being delivered to all of the lines? the reason is that chromium can cause carbides to form in thin sections of casting. The cutting tools at the motor plants would not like this, so chromium was only added to blocks where increased tensile strength was required (class 30 gray iron). The chrome content in class 30 iron was targeted at .032 %.

Just food for thought - nickel is also a strong pearlite stabilizer and would increase the tensile strength of cast iron (similar to chrome, but without the tendency toward carbide formation). Ferro-chromium (not metallic chromium) is a relatively cheap commodity, and, therefore, a good choice for alloying in a high production environment. In smaller job shops - nickel alloying could be used to increase tensile strength in cast iron. In these low production environments - the shop may not want to risk the carbide formation tendency of ferro-chromium. So - this is just conjecture - over the years people familiar with job shop practices may have assumed that nickel was being used in high volume environments.

Very informative post. Thank you for clarifying the process Bruce.

That is an urban myth. The last 3 numbers of the casting were typically cast in both front (area under timing cover) and rear (area covered by the bellhousing) of block. 3970010 have the 010 and 020 because they are last three numbers of blocks in that casting timeframe. The 3970010 and 3970020 blocks.

You will also see this on small blocks made throughout the 60's.
1967 3892657 blocks have 657 and 944. (3892657 and 3896944)
Some 1965 3782870 blocks have 870 and 721. The 3790721 was the predecessor.
So it was a foundry thing to do this.


Its just a coincidence that the 010 and 020 blocks ended in those numbers.

I agree - front and rear housing cores were common among several part numbers. Every time a casting was modified, a new part number was supposed to be assigned, but if the change didn't involve the front or rear casting face - the same old housing core boxes would be used. These front and rear housing cores were made on equipment that was the oldest at Tonawanda. The binder used was actually a derivative of linseed oil. The dimensional tolerance capability of these "oil sand" cores was not great, so it was gradually being phased out in favor of phenolic urethane binders. the "oil sand" front and rear housing core boxes were very old & were used for multiple part number blocks over the years.

If anyone knew, it was the late great John Z. I asked him numerous questions about Chevy SB Heads and he always answered my emails.

Most 307 castings did not get hot rodded because of the small bore size, and they are all two bolt main. Although four bolt mains aren't essential, they are so prevalent and cheap, most folks would prefer to start with a 4 bolt block.

"One interesting fact regarding the Chevy 307 V8 was that it was also manufactured by GM for boat use and sold by the Outboard Marine Corporation as a high performance marine engine. The marine version of this engine produced between 235 and 245 horsepower and even used the same aluminum valve covers that were used in Corvettes and Camaro Z-28s." Quoted from this article: https://www.enginefacts.com/chevrolet307/

Don't know about "kids", but many others have use 307s as a starting point with good results.

https://www.onallcylinders.com/2021/...307-big-power/

https://www.motortrend.com/how-to/su...e-performance/

https://www.onallcylinders.com/2020/...blowing-it-up/

Ok for the sake of discussion. Bergy:


Why were the later 010’s all the same after the mid 1970’s?

2 bolt mains and 4 bolt mains?

And I just called a local guy who has overhauled engines fir a living for decades

The metal is definitely softer on the later blocks.

Explain please.

And as an additional bonus isn’t it true that a flint block could be built as a lower horse motor but not the other way around?

How many LT-1’s 302’s were cast in NY??

Phil - I don’t want to argue. You always draw your own conclusion anyway :-)

Not trying to Argue.

Can you address the questions posed given your stated expertise?

This is from the camaro brochure.

So, you called a machinist who has determined that the brinell hardness reading is greater on later blocks? 😂

Do you know how silly that sounds? All you want to do is argue. PM me if you really have questions.

Quantitative hardness testing on a representative sample of blocks cast on specific dates would be the only way to draw conclusions. I lived this Phil - please don’t just be contrary. PM me if you have questions.

Perfect!

Now with that aside the Marc Dant post is instructive as to the discussion for those so inclined.

The brochure must refer to casting design enhancements. Class 30 cast iron for blocks was metallurgically unchanged.

Two apparent distinct and separate references.

One to a tougher block. The other to 4 bolt main caps.

As an aside I have a detailed Early and later 010 design comparison changes for blocks in images... I can post here if there is interest.

I’m just telling you facts Phil. Your “apparent” conclusions are on you :-)

Bergy,, I have a question. I’ve always heard that 2 freeze plug, 2 bolt main 400 small blocks were better/stronger/heavier castings than the 3 freeze plug 2 and 4 bolt main versions. So I built my 406 with the two freeze plug casting. Can you shed any light on this? I’d appreciate hearing your feedback.

When I don't know I'll tell you Andy - I don't know the answer to your question. As I recall, there was a 400 block that ended in 817 during the 70s. We all felt that it was the highest quality block that we produced. It was the only block that was cast using a single core to form all of the bores and bulkheads. So, it was a lot more dimensionally accurate then the multiple cylinder bore cored blocks.

Here's some good (debatable) reading on that subject

http://garage.grumpysperformance.com...ain-caps.1014/

[I think the 400 SBC 4 bolt blocks have a bad reputation that's probably not fully deserved , the rumor is that the web area of the block is weaker and the outer bolts further weaken the block, but I think its more a case of the extra bolts don,t significantly add to the block rigidity .
the 350 and 400 SBC OEM production blocks were designed to handle 350-400hp max,and when pushed well past that stress level its just logical that they occasionally fail.
if a two bolt block fails the normal response seems to be that
'we should have installed the angled aftermarket main caps'
if a four bolt block fails the normal response seems to be that
'we should have installed the angled aftermarket main caps, because the damn four bolt blocks weaker'
the truth is that by the time your making 500hp neither block with stock main caps keeps the main caps from moving under full loads and adding the splayed main caps while helpful is not a cure, its a band-aid at best, the aftermarket DART block has much thicker castings in the block web area and better and stronger alloys used.]

A direct quote from the Link: http://garage.grumpysperformance.com...ain-caps.1014/

"failure to check for cracks or use of a O.E.M. block at power levels its not designed for can and frequently does result in engine failure,

Most O.E.M. SBC blocks are rated at no more than 400hp, we all know guys pushing them to 500hp but much beyond that its a crap shoot and the blocks eventually going to flex and fail".

Now why would "Most" SBC blocks eventually "Flex and Fail"??

400-500 HP is not a known problem on 302's or LT-1's as far as flex correct?

386,388,618 and 010 blocks weren't cast specialty for 302,327 or 350. They were just blocks that didnt become 302 or LT1 until assembly so I would say yes they would have the same problem as any other block. I've seen more than one block machine shop didn't want to use because of poor casting like center line being off. Also plenty with main caps that were loose and moving around.

Before we begin some commentary. At the risk of additional insults we will attempt to examine factual information. This is supposed to be the premiere Muscle car site right? So guys why not hold the "circle the wagons" stuff for a bit. The moderators/Administrators have been alerted to the conduct in the thread to date - and have done zip to address it - so I will address it with information and evidence.

If all of you are the "experts" on this you will be able to debunk everything I am about to post. However substituting insults in leu of a factual argument is quite self evident, so please be respectful and so will I.

Lets begin.

The Story as we know it:

Nickel was used to harden the bore surfaces so the ring seal is better. Tin was used to make the block heat and cool more evenly. Tin and Nickel are shown as percentages in numbers cast into the block under the timing chain cover.

A "high nickel" block will have either "010" or "020", which indicates 10% and 20% nickel, accordingly.

The best blocks have both tin and nickel, and show two numbers: 010 and 020, which means the block has 10% tin and 20% nickel.

Some of the the early 400 SBC were also 010 and 020 cast and quickly became the go to choice for the circle track racers because they held up and dominated the track conditions the aftermarket followed and that motor became the go to engine for that kind of racing.

When I say 302 and LT-1 I am specifically referring to the 010 casting of both and 010 castings produced in Michigan.

FORD had the Windsor then they had the Cleveland These were technically different block designs and as we will soon see GM did the same thing with the 010 changing the design at least 3 times while keeping the same casting number.

I asked about this. I was told that these subtle changes were accomplished to at first to transition the engine from a high compression centric design then later again to adapt the block to better meet durability and emissions as GM moved to a corporiate engine usage format. These later 010's are the two bolt variants and are easily recognizable by the small pad where the usage designation was stamped which was shared by the 305 also.

The evidence:

Look at the design. Casting is different.

More:

Another: