History Factory storing castings outside to "age"

I 've heard the stories, usually about Ford, engine castings were cured outside for a year before using...
Say it's true, is there proof of this beside a story from Uncle Fred ? Have any of you seen it first hand , reliable info in book or a photo?
It's clear that Chevy didn't age blocks in the 1960's. The date codes on the engine were only a month older the build date of the car...But this might wrong also.... Any truth out there?

 

I was tinkering with a 1958 chevy 283 engine yesterday, it was cast on the 22nd, and assembled on the 23rd of January 1958.

 

I've got a few flathead castings sitting outside "aging".

 

I had a student in the 80's that said he had a block stored outside to I believe "cure" it. He was a bit of a strange duck with some odd ball ideas and it was A Ford engine block by the way.

 

I'm like Alchemy. All my stuff has cured. Now I'm replacing sheetmetal from the curing process.

 

I've always heard that 'cured' engine blocks were ones that had seen service, with the idea that the heat cycles from use would cause the casting to take a 'final' set and reduce dimensional changes at operating temps...

 

I think that it is a story started by someone who read about a seasoned block and though that it meant that someone stored them outside for the season.

@lippy my model A has cancer really bad and I am torn between curing it or just throwing some old worn out inline 6 in it and driving it as a rusted out POS so I can be one of the cool patina guys.

 

Porsche used to (still do?) do this with cylinder barrels. I saw a shot of their storage yard years ago, barrels on pallets all over.

 

I found this with a quick google search. Powermatic machine tools catalog used to have pictures of acres of raw castings sitting outside.



Aging cast iron = Old wife's tale?
60 posts by 29 authors


Kurt Laughlin
1/4/99
This is gonna cost me, but I gotta do it. . .
Reading the other posts on "aging" cast iron, I was doubtful that the "room
temperature anneal" described would do much. So today, I looked into it.
From the Metals Handbook, 8th Edition, Volume 1, published in 1961 by the
American Society for Metals, pg 362 - 363:

"If residual stresses are high enough, they may relieve themselves slightly
at a very slow rate at room temperature. This is the origin of the old
practice of aging castings for three months to a year before machining.
However, modern methods of investigation indicate that a maximum of only 15%
of the residual stress can be relieved by aging, and therefore the practice
is seldom used today. Table 25 shows that aging for 84 days at room
temperature had no stress relieving effect."

[Note 15% is the max theoretically *possible*, not the amount normally
achieved.]

[. . .]

"Castings with residual stress have tension and compression balanced in the
as-cast piece and are dimensionally stable at room temperature. When part
of the surface is removed in machining, the balance of forces is altered.
If the casting is of relatively stiff section, there may be no noticeable
change in dimensions. Distortion will be most evident in castings of low
stiffness from which a large volume of highly stressed metal has been
removed."

"Since the surface of a casting is often the principal site of residual
stresses, a large proportion of the stress is relieved by rough machining,
with consequent maximum distortion. If, before final machining, the casting
is relocated carefully and properly supported in the machine tool fixtures,
acceptable dimensional accuracy will usually be obtained in the finished
piece."

[. . .]

"It is difficult to make general statements concerning the dimensional
stability that can be achieved in a gray iron casting without stress
relieving. However, it is well known that automotive engine blocks are
taken directly from the foundry without stress relieving and are machined to
tolerances of +/- .0002 in. in such areas as crankshaft bearings, camshaft
bearings and cylinder bores. Therefore, if a casting is properly designed,
and cast under controlled conditions, and if proper machining practice is
followed, extremely high dimensional stability can be obtained in many
applications without stress relieving."

"Table 26 illustrates the effect of a stress-relief heat treatment on
cylinder sleeves for a tractor engine. The data show no consistent
improvement of dimensional stability as a result of stress relieving.
Similar results have been obtained for gray iron pistons."

As I thought, "aging castings" is an Old Mechanic's Tale, just like
"crystallizing firing pins" by dry firing.

 

Beaner put the A model back outside for a few years and cure it till theres nothing left of it and you won't have to worry about it. Farmers here have been doing it for years.

 

Fabber I think shotpeening would be faster and achieve more than 15% possibly.

 

I actually have been working on a low budget research project along those lines. The premise is this, that everything comes from the earth which eventually tries to get it back. I throw things in the back of the pickup, what the earth wants back blows out and I keep everything else. I also use rusting old hulks as an example if you wait long enough it will eventually go back to the earth from which it came. LOL

 

I'd think the ideal way to cure a block would be heat cycles. And in a perfect world, the block should be stressed like it would be when the engine was completely assembled.

There's gotta be a way to do that.

 

I used to machine gear boxes for salt spreaders in the 70s and we stored the raw castings outside for a year before machining them. JB

 

I remember reading an article about bmw m12 engines running in the formula one turbo era 1982-86.

These were 1.5 litre engines that put out 1,100-1,400 hp with ridiculous amounts of boost. The article read that they went to the scrap yards to get engines that had been through a full life of heat cycles already to fully stress relieve the blocks because they were more reliable once built into race engines.

It still amazes me that it is possible to make that amount of horsepower out of that size engine.

P

 

That is normally called a seasoned block. Back in the '80s and '90s a seasoned block was preferred by a lot of engine builders.

 

A lot of companies would do that. We did (still do) work for a manufacture of dynamometers and they stored all of their casting outside and wouldn't send them to us for machining or grinding until they were at least a year old. They now just send them to a heat treat shop and have them stress relieved

 

From the Machine shop world. Seasoning referred to the weather seasons. Which means freeze thaw cycle outside. This is a natural stress relief for the castings. In the early 1800s when Southern foundries started to make machine tools they found the castings moved a lot more after machining than castings from the northern factories. No winter freezing. Today almost all precision cast iron castings are heat and/or cryo treated for stress relief.

 

I prefer "seasoned" castings, because I can't afford new stuff.

I always thought "seasoned" meant "used"

 

So, is it safe to safe auto manufacturers didn't or don't "age" cast iron by storing it outside for a year...

 

seasoned castings since the mid 1800s industrial age, meant 1 full year outside for things like lathe beds and other precision machinery

 

I seem to remember Packard storing new engine blocks for around a year to "stress relieve" them. Said the iron would retain it's shape after machining better than taking a new casting and cutting it. Maybe so. it's for sure that any engine I get to fool with has had lots more than a year to work out the stresses.

 

It's OT, but the Fergison/Mcmillian El Mirage/Bonneville streamliner are running a 1 liter Honda that is giving over 1000hp

 

Of course castings were aged, how long and for what purpose(s) varied wildly by mfr and "need". Here's an article from February 1922 issue of Motor Age, where the mechanic is lamenting that the factories aren't aging the blocks long enough before machining.
See the second page.

 

back in the '70's I traveled a bit and saw lathe beds being seasoned outside near puxatawney pa......where the groundhog sees its shadow.............do they still do this.

 

I heard the same thing about Hercules Diesel engines. Some of them would crack a main bearing web. If one survived long enough to need rebuilding, the odds of that one being a good reman was preferred to the odds of a new casting that remained untested by use.

 

I lived near an Allis Chalmers foundry in the 1960s and they always had castings stacked outside. I assumed that they didn't have room and were waiting to move them to their factory.

New castings can have flaws. If an engine has run for 100,000 miles, the casting must be ok.

When I worked at a Ford dealer in 1979, a customer was going on a trip from Wisconsin to California and decided to have all of his hoses and belts replaced before the trip. Three days later, before he left on his trip, the upper radiator hose blew. When it was replaced a flaw could be seen where it separated. Sometimes it's better to have tested than new.

 

BMW did it.

1982 – M12/13* Formula 1 racing engine (http://www.bmwblog.com/2015/04/13/the-history-of-bmw-in-f1/)



This is the holy grail of BMW engines – the scourge of Formula 1 after it matured. Starting from well used M10 iron blocks left outdoors for seasoning (including seasoning by employees urinating on them, or so the story goes) these engines at 1.5 L went on to produce more HP than the engine dynos of the time could measure. In qualifying trim (read ‘hand grenade’) and running upwards of 60 lbs of boost, the engine was said to develop about 1,500 HP. Nothing since has done that. And that is 1 hp per cc. Yikes!

Using electronic Kugelfischer injection and the M12 (Formula 2) cylinder head – which was a conventional DOHC head, unlike the Apfelbeck head, the M12/13* was seriously oversquare with an 89.2 mm bore and 60 mm stroke.

In 1983, the M12/13* was mounted in the Brabham BT52 and proceeded to win the World Championship. Nothing has come close to the power output of the BMW M12/13* in Formula 1 since.

 

I live close to the Chrysler Trenton Engine plant. There were always raw new blocks stored outdoors and I was told they were left out there to season, that it was done for that purpose. Next door neighbor was a dept leader/supervisor and confirmed it. This was back in 69-70 when I had learned of it but it went on for quite some time after. Don'tknow/think that it's still done.