6.2 Redblock Theory

[Robyn]

I really don't have a soft spot for any chunk of iron.

Although my first interaction with the 6.2 was with a 1982 GMC JIMMY
A local gal had it and she took it to a shop for some minor repairs (Little crap...hoses, belts yada yada yada) The mechanic told her she needed to get rid of it soon as these things BLOW UP

I traded her a Dodge Ram Charger for it....

The little Red engine ran to 300K miles for me....NEVER BLEW UP EITHER...

Only issue was the 700R4 tranny scattered all over the street one day going to work......

Swapped in a TH350...called it good.....

I don't think any oddities would be noticed when machining a Red block....

The slight difference in the material is not likely to even be noticed.....A well seasoned machinist MIGHT hear a slight difference in the sound of the cutter on a boring bar when boring cylinders.....MAYBE.....

[2INSANE]

I really don't have a soft spot for any chunk of iron.

Although my first interaction with the 6.2 was with a 1982 GMC JIMMY
A local gal had it and she took it to a shop for some minor repairs (Little crap...hoses, belts yada yada yada) The mechanic told her she needed to get rid of it soon as these things BLOW UP

I traded her a Dodge Ram Charger for it....

The little Red engine ran to 300K miles for me....NEVER BLEW UP EITHER...

Only issue was the 700R4 tranny scattered all over the street one day going to work......

Swapped in a TH350...called it good.....

I don't think any oddities would be noticed when machining a Red block....

The slight difference in the material is not likely to even be noticed.....A well seasoned machinist MIGHT hear a slight difference in the sound of the cutter on a boring bar when boring cylinders.....MAYBE.....

Ok thanks again for sharing your knowledge.

I am not gonna ask anymore questions and waste anymore time until the Lab test results are in. The test tubes have not arrived yet.

[Robyn]

I am curious.....

[More Power]

....clip...

Just goes to show how others are assuming it has higher nickel content reinforcing the Redblock Theory…

There are hundreds of posts out there with assumptions but no solid proof…

I had a red block engine rebuilt in the 1990's. The block itself was crack free, but the heads had to be replaced. That experience launched The Diesel Page.

Both metallurgically and in engineering design, engine manufacturers are always pushing for improvements (power, cost, fuel efficiency, etc). The 6.2/6.5 saw many changes in their design life, both in metallurgy and design. Some of those changes helped and some didn't. When a big change was introduced, GM included some sort of ad verbiage about the improvement. This is likely where the block alloy came into our sphere of knowledge.

Concerning the "red blocks". There are better choices... The "599" for example. Those cast by Navistar beginning in 2001 as well. The newest ones with a cast iron block girdle (P400) being the very best. I'm curious why you're interested in the red blocks.

[2INSANE]

I'm curious why you're interested in the red blocks.

I have had a lot of people ask me this same question since I started this thread and started searching for a 6.2 Redblock.

I have 2 reasons for my interest.

1. I want to know if the Redblock truly has higher nickel. This theory/assumptions has been around for 41 years. I am awestruck that no one has tried to prove it, at least no one to my knowledge. 41 years is a long long time people have been saying it has higher nickel content without substantial scientific proof.I aim to solve this soon! Hopefully in a month or two. I need test tubes and a later 84+ 6.2 diesel motor to get block samples. Should have one here soon in about a week.

2. I bought my first truck for only $500 when I was 19 years old. It was a 1983 Gmc K2500 with a painted black 6.2 Redblock. It sat in some guys yard for over 5 years. I replaced all the fluids in it, filters, batteries, glow plugs and it fired right up. It ran choppy until I added fresh fuel to it. I drove that thing everywhere and towed a lot of heavy stuff with it. It was my first off-road vehicle as well. One point of time, my brother drove his Suzuki Samurai in the bed of the truck and we drove around town with it in the back! Lol! The odometer rolled over at least 3-4 times. A lot of great memories. It finally gave out about 5 years ago. I replaced the motor with a 6.2 J Code takeout and sold the truck to a coworker. I still see it running around town sometimes. Wish I kept it. Also, I am a huge 6.2/6.5 diesel enthusiast. The Redblock cast first came out in 1981 which happens to be my birth year. So because of this nostalgia relationship between myself and the Redblock 6.2, I think it would be super cool to build a 41 year old 6.2 block, modernize and bomb proof it, put it in a 41 year old light weight GM car or truck and drive it around. I’ve researched here on thedieselpage that a gentleman put a 6.2 diesel in a Corvette and was getting 45+MPG. In this modern day of age, that would be so cool and would get a lot of attention and respect. Even with minor cracks in the webs, it would prove that even a bad block can still be good and be rebuilt with modern technology. I guess one could say I do have a soft spot for the 6.2 Redblock. But all of this nostalgia does not mean nothing to me unless this higher nickel content is true and I will not build a Redblock unless it is true.

Edit:

Pics of my 83 gmc 6.2 with a fresh rattle can paint job. Sold it shortly after.

[JohnC]

I guess one could say I do have a soft spot for the 6.2 Redblock. But all of this nostalgia does not mean nothing to me unless this higher nickel content is true

Are you sure you want to know? Sounds like it might be traumatic if it turns out to be much ado about nothing!

[2INSANE]

Are you sure you want to know? Sounds like it might be traumatic if it turns out to be much ado about nothing!

Heck yeah I want to know! It is a fun experiment and will help me determine if I want to build up a Redblock. It will take thousands of dollars to do so and with that kind of money being thrown at a 41 year old motor, it would help me sleep better at night knowing it has higher nickel! Lol! And then it would go boom! Lol

[More Power]

...41 years is a long long time people have been saying it has higher nickel content without substantial scientific proof....

If anyone sees something "official" here in TDP in our published content concerning engine design, it likely originated with GM... either in their published literature or perhaps in a conversation I had with a GM Powertrain engineer/tech/etc., or through our own testing.

For example... Here's a corner of a 660 block we cut apart to help determine whether what we heard about cyl boring would affect cyl wall durability.

65-Cyl-Wall-Thickness-01.jpg

[2INSANE]

If anyone sees something "official" here in TDP in our published content concerning engine design, it likely originated with GM... either in their published literature or perhaps in a conversation I had with a GM Powertrain engineer/tech/etc., or through our own testing.

For example... Here's a corner of a 660 block we cut apart to help determine whether what we heard about cyl boring would affect cyl wall durability.

65-Cyl-Wall-Thickness-01.jpg

Wow! Those walls are thin! I’ll have to be extra careful getting drill shaving samples. Got any more of those block pics? In your many years, have you ever tested for the nickel content in any 660 cast?

[sctrailrider]

If I were going to drill anywhere it would be the bellhousing flange...

[2INSANE]

Here’s a couple more pics of my old 83 Redblock that I dug out of an old Flashdrive.

If I were going to drill anywhere it would be the bellhousing flange...

Was thinking that would be a good spot too! What did you think about donating some P400 Block samples to this experiment?

The test tubes arrived. I’ll start collecting samples and get pics for yal.

[sctrailrider]

Yes I'll contribute a P sample, I'll message you my address...

[2INSANE]

Yes I'll contribute a P sample, I'll message you my address...

That is awesome! Thank you sooo much! I can mail a test tube your way!

Sample #1

Red Block Verification.





Safe sample location found and surface area cleaned with a grinder.





Weight of 5 grams is equivalent to the weight of a nickel as seen in photo. I used my wife’s baking scale and made sure it was zeroed out.



I used a clean long piece of paper to catch the shavings and carefully placed them on the scale.



The size of hole left on the Redblock did not come close to the boundary of the main cast.



Scale zeroed out with an empty test tube and placed material in the tube. Then I scaled it out again to make sure 5 grams was in there.



I labeled the test tube and now waiting on more samples. I will get a sample from my 2003 NAVSTAR Optimizer and ask a customer if they would donate some 1985 6.2 Samples.

[Robyn]

I like it..
Serious scientific data being gathered.

Gonna finally separate the Fly Chit from the Pepper.

It will be real interesting to see what these tests reveal.....

Urban legends are so much a part of society that it is nearly impossible to believe a lot of things......

What do you suppose we will find....Was GM using old bed springs, ground up Toyota blocks with an occasional Honda dropped into the mix for good measure.....or maybe some old crushed Studebaker and International iron....or was it whatever was available from China Iron Company ????
This is going to be worth the wait....
Missy sits waiting the real deal data

[2INSANE]

I like it..
Serious scientific data being gathered.

Gonna finally separate the Fly Chit from the Pepper.

It will be real interesting to see what these tests reveal.....

Urban legends are so much a part of society that it is nearly impossible to believe a lot of things......

What do you suppose we will find....Was GM using old bed springs, ground up Toyota blocks with an occasional Honda dropped into the mix for good measure.....or maybe some old crushed Studebaker and International iron....or was it whatever was available from China Iron Company ????
This is going to be worth the wait....
Missy sits waiting the real deal data

Definitely a fun and interesting project! When I drilled into the block, it felt like I was drilling into an Exhaust Manifold. The drill shavings were more gritty and powder then big curly chunks.

I was thinking about filling in the hole with some welding Rod. I don’t think it would hurt the block to weld on it where I collected the sample. During your years of service, what Rod seemed to work best on the 6.2 block?

[sctrailrider]

Why , your asking for trouble welding iron when it's not needed. And it's normal for iron to be gritty, it's not like steel.

[Robyn]

What trail Rider said

Leave the welder in the corner.

If the little hole bothers you...mix up some JB Weld and fill it....Let it harden and sand the surface flush....

Welding cast iron is a very tedious process of preheating....Welding and then post heating to allow a slow cool down.....

I have done it.....Lets not go there...

[More Power]

Wow! Those walls are thin! I’ll have to be extra careful getting drill shaving samples. Got any more of those block pics? In your many years, have you ever tested for the nickel content in any 660 cast?

I have many pics of engine parts with various problems. Some were sent to me by members, some were my own. I worked in a science department at UM for a long time - coinciding with the production life of the 6.2/6.5. We had several analytical instruments that were used to perform elemental analysis. I never felt a need to look at the iron in these engines. I analyzed our well water once...

Btw - to begin an analysis of iron shavings, a sample will first be weighed precisely on a lab scale - probably somewhere between 1 to 5 grams. Then, the iron will be dissolved in an acid - nitric or hydrocloric, diluted to some degree to produce a clear liquid. The liquid will then be analyzed in a plasma flame, with the elemental analysis being done optically, compared against a "standard" to produce a PPM (parts per million) for all primary elements found in the sample (there are always several trace elements). Every element produces its own color flame within the plasma flame, and an alloy will produce many colors, most not visible/discernible to the human eye. That's where the instrument's optics and calibration come into play. Our department had two ICAP (Inductively Coupled Argon Plasma) instruments. Each one was mega bucks. We had other types of spectrometers as well, including micro-beam x-ray machines that could do elemental analysis.

If there's nickel in the alloy you're looking at, it'll be identified and quantified. But then, what's normal and is that nickel concentration different when compared to other year blocks? It's all interesting though. I always enjoyed lab work.

[Robyn]

Good bet GM won't give up the recipe they used on the various years of blocks.

I am very suspicious that the curing process and the stress relieving process were to blame for the cracking issues more than the nickel content....

As in they skipped it...or it was a chemical bath of some sort to save $$$$

[2INSANE]

I mentioned before that I work at a recycle center. These pictures I just took show that the bales recycled, are mixed with all kinds of metals. Copper, Aluminum, Lead, Gold, Silver, Platinum, Titanium, etc. These metals have been refined and processed xxxxx amounts of times. I believe the newer cast blocks are going to have all kinds of alloys in them. Which I think is the reason they are stronger. These bales get sold to China, Mexico and Canada. The United States does not produce much at all. Probably the number 1# consumer nation in the world.







Back in the 1980’s the United States did a lot more production instead of consumption/recycling. The metals back then were refined and processed only a couple of times, if that and I’m assuming will have far more iron in the casts compared to the newer casts. Anything with high iron is prone to cracking. Like a wood stove… If the Redblock does have higher nickel, I feel safe to say that the nickel was intentionally added into the casts. The newer casts, not so much.

When I look at these bales of metal, It is fun to think that this bale could be GMs next and finest diesel motor… Or a new line of “Improved Heads” from China. lol!!

Also on a legality side of things… There is a chance I could get sued by GM or some company for exposing the metal content in the blocks. It would be a US Patent issue. I will do some research on this just to be sure. If I am not mistaken, after 30 years the Patent Laws no longer apply.

JB Weld is a great idea! Didn’t think of that.