Hi folks,

This question came into my head a few days ago. I often hear people
suggesting that the latest vehicle engines last longer and are more
trouble-free than older engines. But I also hear people saying, just as
often, "They don't make them like they used to".

I was looking at a Dennis Z Type lawnmower a few days ago. I am hoping
to acquire one. For those who don't know, this is a legendary machine. I
think its engine is probably the best lawnmower engine ever made. It has
forced lubrication and an oil filter, complete with a passage for oil
through the crankshaft, and was introduced in 1922.

Now it's possible that one might look back at older products and view
them as being superior because all the poor quality products from the
era wore out and were replaced. It's also likely that the answer to the
question will depend on the type of engine you look at, and the quality
of construction. But I'll leave it as a general question, as I'm
interested to hear anyone's experience.

I get the impression that perhaps engine technology is moving in two
opposing directions. On the one hand, improving technology such as
better lubricants, filtration and bearing materials, are resulting in
components lasting longer. But on the other hand, the whole industry
appears to be moving towards less maintainable engines. Engines which
are wholly dependent on electronics, sometimes with coated rather than
lined cylinders. Engines which are difficult for anyone to maintain at
home. Perhaps this is why I don't hear people talk about replacing
piston rings, or having crankshafts regound anymore? Or perhaps these
parts last for the lifetime of the vehicle?

I'd be interested to hear people's opinions. I'd also be very interested
to see data comparing wear rates in modern and old engines, if anyone
knows where I can find such data.

Best wishes,

Chris Tidy

On Aug 1, 8:28*pm, Christopher Tidy
wrote:
Hi folks,

This question came into my head a few days ago. I often hear people
suggesting that the latest vehicle engines last longer and are more
trouble-free than older engines. But I also hear people saying, just as
often, "They don't make them like they used to".

I was looking at a Dennis Z Type lawnmower a few days ago. I am hoping
to acquire one. For those who don't know, this is a legendary machine. I
think its engine is probably the best lawnmower engine ever made. It has
forced lubrication and an oil filter, complete with a passage for oil
through the crankshaft, and was introduced in 1922.

Now it's possible that one might look back at older products and view
them as being superior because all the poor quality products from the
era wore out and were replaced. It's also likely that the answer to the
question will depend on the type of engine you look at, and the quality
of construction. But I'll leave it as a general question, as I'm
interested to hear anyone's experience.

I get the impression that perhaps engine technology is moving in two
opposing directions. On the one hand, improving technology such as
better lubricants, filtration and bearing materials, are resulting in
components lasting longer. But on the other hand, the whole industry
appears to be moving towards less maintainable engines. Engines which
are wholly dependent on electronics, sometimes with coated rather than
lined cylinders. Engines which are difficult for anyone to maintain at
home. Perhaps this is why I don't hear people talk about replacing
piston rings, or having crankshafts regound anymore? Or perhaps these
parts last for the lifetime of the vehicle?

I'd be interested to hear people's opinions. I'd also be very interested
to see data comparing wear rates in modern and old engines, if anyone
knows where I can find such data.

Best wishes,

Chris Tidy


I tend to agree with you to some degree, however, as consumers our
expectations have gone up over the years. It wasn't that long ago
that cars were worn out at 20K miles, and that automobiles came with
instructions that told you how to repair the babbit bearings in the
engines yourself. Now, a car with 200K miles is normal, even barely
broken in. Machines made by craftsman who understood the fine details
of quality machinery were rare and highly sought after, as they had
under one hat engineering, design, assembly, and maintenance skills,
but they couldn't make them very fast or very cheap. Now these skills
are most commonly segregated to individuals, with less and less having
all those abilities at one time. Competition has ensured that quality
and endurance are important, as well as cost. Modern automotive
engines are designed and can be easily reproduced with tolerances
unattainable not that long ago, and the tight tolerances, combined
with carefully worked out assembly processes ensure that the cost
comes down with little to no loss in quality. During the Civil War,
every citizen soldier had his own musket, each of a slightly different
caliber, so they had to cast their own bullets, and repairing them was
difficult due to lack of interchangeability. Mass manufacturing
methods not that long afterwards resulted in rifles being crafted in
great numbers with precision, which drove the cost down and the
deadliness of warfare up.

That said, all engineering design is a compromise. Quite often a
lower quality part is selected for a car or other machinery because it
keeps the cost down. Rarely do we notice these things, and when we
do, it's often a big deal. If money is not object, someone somewhere
will build you the machine you want with the very best components that
you want, but it will cost a lot of money, be hard to find parts for,
and only used by limited numbers of people. We as consumers also have
to make a compromise based on our needs, wants, and wallet, and while
I'd like to have a Bugatti in the driveway, I don't have the money or
a practical need for it. I just need a car I can rack up the miles on
with low maintenance (as compared to my Triumphs...) and do everything
else I need it to do.

"Christopher Tidy" wrote in message
...
Hi folks,

This question came into my head a few days ago. I often hear people
suggesting that the latest vehicle engines last longer and are more
trouble-free than older engines. But I also hear people saying, just as
often, "They don't make them like they used to".



short answer, "yes", at least for automotive use. I have 1936, 1938, 1951,
1959, 1985, 1986, 1993, 1997, and 2001 vehicles under my purview. up
through the 51 year car, 150K miles or so was the limit - at that point the
bores were 40 to 60 over, rings shot, no compression, crank oval, no oil
pressure, etc. 59 is good for 200K easy. there was a major change in the
metalurgy of the engine block, etc, as I understand it - we can debate what
changed, but the longevity is just not an issue


** Posted from http://www.teranews.com **

Christopher Tidy wrote:

This question came into my head a few days ago. I often hear people
suggesting that the latest vehicle engines last longer and are more
trouble-free than older engines. But I also hear people saying, just as
often, "They don't make them like they used to".

I would think advances in metalurgy, newer more ridgid machines that can hold closer
tolerances in making your engine parts, and oil designed with better additive packages
would tend to improve engine life. The electronics are a plus in my mind. I don't miss
setting breaker points and checking timing.

Fuel injection sure beats carburation and with the emissions requirements, we have sensors
that monitor a/f ratio to allow the computer to adjust engine parameters for good
performance. They are tilted toward lower emissions.

And recent vehicals have ODBII which I have found very helpful in spotting a problem
before it becomes serious.

I think they are better. But if you want any engine, new or old to last, change the oil
often. My car has a light that comes on every 5500 miles that tells me to change the
oil, I change the oil far sooner than that.

Wes

On Sat, 02 Aug 2008 03:28:26 +0000, Christopher Tidy
wrote:

Hi folks,

This question came into my head a few days ago. I often hear people
suggesting that the latest vehicle engines last longer and are more
trouble-free than older engines. But I also hear people saying, just as
often, "They don't make them like they used to".

I was looking at a Dennis Z Type lawnmower a few days ago. I am hoping
to acquire one. For those who don't know, this is a legendary machine. I
think its engine is probably the best lawnmower engine ever made. It has
forced lubrication and an oil filter, complete with a passage for oil
through the crankshaft, and was introduced in 1922.

Now it's possible that one might look back at older products and view
them as being superior because all the poor quality products from the
era wore out and were replaced. It's also likely that the answer to the
question will depend on the type of engine you look at, and the quality
of construction. But I'll leave it as a general question, as I'm
interested to hear anyone's experience.

I get the impression that perhaps engine technology is moving in two
opposing directions. On the one hand, improving technology such as
better lubricants, filtration and bearing materials, are resulting in
components lasting longer. But on the other hand, the whole industry
appears to be moving towards less maintainable engines. Engines which
are wholly dependent on electronics, sometimes with coated rather than
lined cylinders. Engines which are difficult for anyone to maintain at
home. Perhaps this is why I don't hear people talk about replacing
piston rings, or having crankshafts regound anymore? Or perhaps these
parts last for the lifetime of the vehicle?

I'd be interested to hear people's opinions. I'd also be very interested
to see data comparing wear rates in modern and old engines, if anyone
knows where I can find such data.

Best wishes,

Chris Tidy

I ran two little 72cc Honda 4 stroke motorcycles for years. (one
replaced the other) both ran for 15,000 to 17,000 miles and were run
at 6,000 rpm at top speeds of 60km/hr in traffic. They got necessary
servicing and were utterly reliable.

these were replaced by a kawasaki BR250 that I ran for 10 years.
it developed an incredible engine vibration so I had it torn down and
the problem resolved and rebuilt. it turned out that one of the main
ball bearing cages has broken up.
I got a "you've gotta come and see this" call from the guy doing the
work. at 80,000km I think, the honing marks werent even scuffed on
the cylinder bore, there was no corrosion anywhere in the galleries of
the engine, in short once the faulty parts were replaced the engine
went back together in new condition.
the BR has gone through a number of owners since I sold it, the
current owner has it in pride of place in his lounge as a classic
bike.

I rate the hondas as little engines. I flogged the daylights out of
them and never once did they cause me problems.

engines since the 70's have been absolutley reliable if you service
them.

btw Hyundai has an engine in the excel which is embossed on the engine
as suitable for 150,000km without adjustment. that says something.

I'm sure it is in the metallurgy and the QA. but yes my experience is
that my engines have lasted far far longer than my fathers.
Stealth Pilot

On Sat, 02 Aug 2008 03:28:26 +0000, Christopher Tidy
wrote:

Hi folks,

This question came into my head a few days ago. I often hear people
suggesting that the latest vehicle engines last longer and are more
trouble-free than older engines. But I also hear people saying, just as
often, "They don't make them like they used to".

I was looking at a Dennis Z Type lawnmower a few days ago. I am hoping
to acquire one. For those who don't know, this is a legendary machine. I
think its engine is probably the best lawnmower engine ever made. It has
forced lubrication and an oil filter, complete with a passage for oil
through the crankshaft, and was introduced in 1922.

Now it's possible that one might look back at older products and view
them as being superior because all the poor quality products from the
era wore out and were replaced. It's also likely that the answer to the
question will depend on the type of engine you look at, and the quality
of construction. But I'll leave it as a general question, as I'm
interested to hear anyone's experience.

I get the impression that perhaps engine technology is moving in two
opposing directions. On the one hand, improving technology such as
better lubricants, filtration and bearing materials, are resulting in
components lasting longer. But on the other hand, the whole industry
appears to be moving towards less maintainable engines. Engines which
are wholly dependent on electronics, sometimes with coated rather than
lined cylinders. Engines which are difficult for anyone to maintain at
home. Perhaps this is why I don't hear people talk about replacing
piston rings, or having crankshafts regound anymore? Or perhaps these
parts last for the lifetime of the vehicle?

I'd be interested to hear people's opinions. I'd also be very interested
to see data comparing wear rates in modern and old engines, if anyone
knows where I can find such data.

Best wishes,

Chris Tidy



The Toyota 22re what a great engine, energizer bunny indeed keeps
going and going.....
They did have a few flaws, ie. timing chain tensioners but
resolveable, seen more than afew with 300k and still running.

Fuel injection is really one of the greatest improvement towards
longevity. Carbs tend to run rich washing down the cylinder walls
with gas, which is not a good lubericant. ED

Christopher Tidy wrote in
:

Hi folks,

This question came into my head a few days ago. I often hear people
suggesting that the latest vehicle engines last longer and are more
trouble-free than older engines. But I also hear people saying, just as
often, "They don't make them like they used to".


I can't vouch for lawnmower engines, but for automobile engines, the
designed life expectancy is ever climbing. I work as an engineer in the
automotive engine design and manufacturing industry. The designed life
expectancy of engine components for most manufacturers is 150,000 miles
minimum, some are higher, some slightly lower, but pretty much the
standard is 150k.
These components must go 150k before any appreciable wear is shown. This
means the actual useful life of the components is closer to 200-250k (or
beyond). Emissions laws pushed this to begin with, since the vehicle is
required to still pass emissions at 100k minimum. But the quality aspect
also played a role.



--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

Bernie wrote: "During the Civil War,
every citizen soldier had his own musket, each of a slightly different
caliber, so they had to cast their own bullets, and repairing them was
difficult due to lack of interchangeability. Mass manufacturing
methods not that long afterwards resulted in rifles being crafted in
great numbers with precision, which drove the cost down and the
deadliness of warfare up."

Buncha crap, Bernie. Muskets and ammunition were mass produced during the civil war period. I read
your post with some interest until I got to that part. It totally denigrated anything else you had
to say. The "one bad apple in the barrel thing", don't you know.

Bob Swinney




"Carl M" wrote in message
...
On Aug 1, 8:28 pm, Christopher Tidy
wrote:
Hi folks,

This question came into my head a few days ago. I often hear people
suggesting that the latest vehicle engines last longer and are more
trouble-free than older engines. But I also hear people saying, just as
often, "They don't make them like they used to".

I was looking at a Dennis Z Type lawnmower a few days ago. I am hoping
to acquire one. For those who don't know, this is a legendary machine. I
think its engine is probably the best lawnmower engine ever made. It has
forced lubrication and an oil filter, complete with a passage for oil
through the crankshaft, and was introduced in 1922.

Now it's possible that one might look back at older products and view
them as being superior because all the poor quality products from the
era wore out and were replaced. It's also likely that the answer to the
question will depend on the type of engine you look at, and the quality
of construction. But I'll leave it as a general question, as I'm
interested to hear anyone's experience.

I get the impression that perhaps engine technology is moving in two
opposing directions. On the one hand, improving technology such as
better lubricants, filtration and bearing materials, are resulting in
components lasting longer. But on the other hand, the whole industry
appears to be moving towards less maintainable engines. Engines which
are wholly dependent on electronics, sometimes with coated rather than
lined cylinders. Engines which are difficult for anyone to maintain at
home. Perhaps this is why I don't hear people talk about replacing
piston rings, or having crankshafts regound anymore? Or perhaps these
parts last for the lifetime of the vehicle?

I'd be interested to hear people's opinions. I'd also be very interested
to see data comparing wear rates in modern and old engines, if anyone
knows where I can find such data.

Best wishes,

Chris Tidy


I tend to agree with you to some degree, however, as consumers our
expectations have gone up over the years. It wasn't that long ago
that cars were worn out at 20K miles, and that automobiles came with
instructions that told you how to repair the babbit bearings in the
engines yourself. Now, a car with 200K miles is normal, even barely
broken in. Machines made by craftsman who understood the fine details
of quality machinery were rare and highly sought after, as they had
under one hat engineering, design, assembly, and maintenance skills,
but they couldn't make them very fast or very cheap. Now these skills
are most commonly segregated to individuals, with less and less having
all those abilities at one time. Competition has ensured that quality
and endurance are important, as well as cost. Modern automotive
engines are designed and can be easily reproduced with tolerances
unattainable not that long ago, and the tight tolerances, combined
with carefully worked out assembly processes ensure that the cost
comes down with little to no loss in quality.
That said, all engineering design is a compromise. Quite often a
lower quality part is selected for a car or other machinery because it
keeps the cost down. Rarely do we notice these things, and when we
do, it's often a big deal. If money is not object, someone somewhere
will build you the machine you want with the very best components that
you want, but it will cost a lot of money, be hard to find parts for,
and only used by limited numbers of people. We as consumers also have
to make a compromise based on our needs, wants, and wallet, and while
I'd like to have a Bugatti in the driveway, I don't have the money or
a practical need for it. I just need a car I can rack up the miles on
with low maintenance (as compared to my Triumphs...) and do everything
else I need it to do.

** Posted from http://www.teranews.com **

Sorry. My retort should have been directed to carl m, or whoever the pseudonym was. My newsreader
must have appended the wrong name. Apologies to Bernie.

"Robert Swinney" wrote in message ...
Bernie wrote: "During the Civil War,
every citizen soldier had his own musket, each of a slightly different
caliber, so they had to cast their own bullets, and repairing them was
difficult due to lack of interchangeability. Mass manufacturing
methods not that long afterwards resulted in rifles being crafted in
great numbers with precision, which drove the cost down and the
deadliness of warfare up."

Buncha crap, Bernie. Muskets and ammunition were mass produced during the civil war period. I read
your post with some interest until I got to that part. It totally denigrated anything else you had
to say. The "one bad apple in the barrel thing", don't you know.

Bob Swinney




"Carl M" wrote in message
...
On Aug 1, 8:28 pm, Christopher Tidy
wrote:
Hi folks,

This question came into my head a few days ago. I often hear people
suggesting that the latest vehicle engines last longer and are more
trouble-free than older engines. But I also hear people saying, just as
often, "They don't make them like they used to".

I was looking at a Dennis Z Type lawnmower a few days ago. I am hoping
to acquire one. For those who don't know, this is a legendary machine. I
think its engine is probably the best lawnmower engine ever made. It has
forced lubrication and an oil filter, complete with a passage for oil
through the crankshaft, and was introduced in 1922.

Now it's possible that one might look back at older products and view
them as being superior because all the poor quality products from the
era wore out and were replaced. It's also likely that the answer to the
question will depend on the type of engine you look at, and the quality
of construction. But I'll leave it as a general question, as I'm
interested to hear anyone's experience.

I get the impression that perhaps engine technology is moving in two
opposing directions. On the one hand, improving technology such as
better lubricants, filtration and bearing materials, are resulting in
components lasting longer. But on the other hand, the whole industry
appears to be moving towards less maintainable engines. Engines which
are wholly dependent on electronics, sometimes with coated rather than
lined cylinders. Engines which are difficult for anyone to maintain at
home. Perhaps this is why I don't hear people talk about replacing
piston rings, or having crankshafts regound anymore? Or perhaps these
parts last for the lifetime of the vehicle?

I'd be interested to hear people's opinions. I'd also be very interested
to see data comparing wear rates in modern and old engines, if anyone
knows where I can find such data.

Best wishes,

Chris Tidy


I tend to agree with you to some degree, however, as consumers our
expectations have gone up over the years. It wasn't that long ago
that cars were worn out at 20K miles, and that automobiles came with
instructions that told you how to repair the babbit bearings in the
engines yourself. Now, a car with 200K miles is normal, even barely
broken in. Machines made by craftsman who understood the fine details
of quality machinery were rare and highly sought after, as they had
under one hat engineering, design, assembly, and maintenance skills,
but they couldn't make them very fast or very cheap. Now these skills
are most commonly segregated to individuals, with less and less having
all those abilities at one time. Competition has ensured that quality
and endurance are important, as well as cost. Modern automotive
engines are designed and can be easily reproduced with tolerances
unattainable not that long ago, and the tight tolerances, combined
with carefully worked out assembly processes ensure that the cost
comes down with little to no loss in quality.
That said, all engineering design is a compromise. Quite often a
lower quality part is selected for a car or other machinery because it
keeps the cost down. Rarely do we notice these things, and when we
do, it's often a big deal. If money is not object, someone somewhere
will build you the machine you want with the very best components that
you want, but it will cost a lot of money, be hard to find parts for,
and only used by limited numbers of people. We as consumers also have
to make a compromise based on our needs, wants, and wallet, and while
I'd like to have a Bugatti in the driveway, I don't have the money or
a practical need for it. I just need a car I can rack up the miles on
with low maintenance (as compared to my Triumphs...) and do everything
else I need it to do.

** Posted from http://www.teranews.com **

** Posted from http://www.teranews.com **

On Aug 2, 1:56*am, "William Noble" wrote:
"Christopher Tidy" wrote in message

...

Hi folks,

This question came into my head a few days ago. I often hear people
suggesting that the latest vehicle engines last longer and are more
trouble-free than older engines. But I also hear people saying, just as
often, "They don't make them like they used to".

short answer, "yes", at least for automotive use. *I have 1936, 1938, 1951,
1959, 1985, 1986, 1993, 1997, and 2001 vehicles under my purview. *up
through the 51 year car, 150K miles or so was the limit - at that point the
bores were 40 to 60 over, rings shot, no compression, crank oval, no oil
pressure, etc. *59 is good for 200K easy. there was a major change in the
metalurgy of the engine block, etc, as I understand it - we can debate what
changed, but the longevity is just not an issue

** Posted fromhttp://www.teranews.com**

In additions to metallurgical advances, there have also been major,
good changes in lubricating oil and manufacturing precision.

I was talking to a friend who runs an engine rebuilding business,
specializing in rebuilding antique and classic engines. I told him I
was looking for plastigauge in a parts store, but they didn't even
know what it was.

He said he does not check clearances on new bearings when using new
cranks, or even when he has turned a crank himself and measures
journals. He says bearings, and new cranks, are the nominal size the
mfg says they are, to a perfectly adequate precision, not like years
ago. He says measurement capability and machining operations are much
improved today.

"Anthony" wrote in message
...
Christopher Tidy wrote in
:

Hi folks,

This question came into my head a few days ago. I often hear people
suggesting that the latest vehicle engines last longer and are more
trouble-free than older engines. But I also hear people saying, just as
often, "They don't make them like they used to".


I can't vouch for lawnmower engines, but for automobile engines, the
designed life expectancy is ever climbing. I work as an engineer in the
automotive engine design and manufacturing industry. The designed life
expectancy of engine components for most manufacturers is 150,000 miles
minimum, some are higher, some slightly lower, but pretty much the
standard is 150k.
These components must go 150k before any appreciable wear is shown. This
means the actual useful life of the components is closer to 200-250k (or
beyond). Emissions laws pushed this to begin with, since the vehicle is
required to still pass emissions at 100k minimum. But the quality aspect
also played a role.



Don't forget also that the specific power output has climbed and fuel
consumption fallen.

I learned to drive in 1960 on my father's 100E Ford Prefect (UK model). It
had an 1172 cc engine which gave 36 bhp and a 0-60 time of 29 seconds. As I
remember, it did about 28 mpg on a long run. Recommended oil changes at 300
miles, 1000 miles then every 5000 miles, and remove cylinder heard and
decarbonise at every 12,000 miles.

Compare that with any modern 1.1 litre car engine.

Fuel injection is really one of the greatest improvement towards
longevity. Carbs tend to run rich washing down the cylinder walls
with gas, which is not a good lubericant. ED

Absolutely. Mercedes took an engine with a lifespan of appx.120K miles and
installed mechanical injection and it then would live for appx. 250K.
Engine management is the key, instead of limping around with improper
jetting for 15 years an FI system makes changes as needed and now alerts you
to problems.
Dodge decided it's engines were running so well that they could save money
on cyl heads and returned tre 1930's system of boring the seats directly
into the iron, drastically reducing longetivety on it's engines and keeping
automotive machinist's families fed.
--
Stupendous Man,
Defender of Freedom, Advocate of Liberty

Don Stauffer in Minnesota wrote:

In additions to metallurgical advances, there have also been major,
good changes in lubricating oil and manufacturing precision.

I was talking to a friend who runs an engine rebuilding business,
specializing in rebuilding antique and classic engines. I told him I
was looking for plastigauge in a parts store, but they didn't even
know what it was.

He said he does not check clearances on new bearings when using new
cranks, or even when he has turned a crank himself and measures
journals. He says bearings, and new cranks, are the nominal size the
mfg says they are, to a perfectly adequate precision, not like years
ago. He says measurement capability and machining operations are much
improved today.


Sure. Today they are made under computer control, instead of union
workers.


--
http://improve-usenet.org/index.html

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm

Sporadic E is the Earth's aluminum foil beanie for the 'global warming'
sheep.

On Aug 2, 8:12*am, "Robert Swinney" wrote:
Sorry. *My retort should have been directed to carl m, or whoever the pseudonym was. *My newsreader
must have appended the wrong name. *Apologies to Bernie.

"Robert Swinney" wrote in ...
Bernie wrote: * "During the Civil War,

every citizen soldier had his own musket, each of a slightly different
caliber, so they had to cast their own bullets, and repairing them was
difficult due to lack of interchangeability. *Mass manufacturing
methods not that long afterwards resulted in rifles being crafted in
great numbers with precision, which drove the cost down and the
deadliness of warfare up."

Buncha crap, Bernie. *Muskets and ammunition were mass produced during the civil war period. *I read
your post with some interest until I got to that part. *It totally denigrated anything else you had
to say. *The "one bad apple in the barrel thing", don't you know.

Bob Swinney

SNIP

My bad. I was a bit distracted and forgot to check my facts. I had
the wrong war in mind. Haven't had an opportunity to spend much time
absorbing details of history like that in a really long time, so I'm
really rusty.

Your friend is an idiot. He risks a destroyed engine and labor to redo
it to some parts store flunky that hands him the wrong bearings;
perhaps a returned box that lists correct size, but has bearings
someone extchanged in the box. Perhaps a machine shop apprentice who
sneezed when punching in the finished OD into the CNC crank grinder.
Anything with the Human factor contributing is guarenteed to **** you
up at some point. And don't think machine made and packaged bearings
can't be defective. I once got a set of rod bearings that had skipped
the punch step that puts the anti spin tang on the end of the shell.
Just guess what would have happened if I had installed them.
JR
Dweller in te cellar

On Sat, 2 Aug 2008 08:24:37 -0700 (PDT), Don Stauffer in Minnesota
wrote:

On Aug 2, 1:56*am, "William Noble" wrote:
"Christopher Tidy" wrote in message

...

Hi folks,

This question came into my head a few days ago. I often hear people
suggesting that the latest vehicle engines last longer and are more
trouble-free than older engines. But I also hear people saying, just as
often, "They don't make them like they used to".

short answer, "yes", at least for automotive use. *I have 1936, 1938, 1951,
1959, 1985, 1986, 1993, 1997, and 2001 vehicles under my purview. *up
through the 51 year car, 150K miles or so was the limit - at that point the
bores were 40 to 60 over, rings shot, no compression, crank oval, no oil
pressure, etc. *59 is good for 200K easy. there was a major change in the
metalurgy of the engine block, etc, as I understand it - we can debate what
changed, but the longevity is just not an issue

** Posted fromhttp://www.teranews.com**

In additions to metallurgical advances, there have also been major,
good changes in lubricating oil and manufacturing precision.

I was talking to a friend who runs an engine rebuilding business,
specializing in rebuilding antique and classic engines. I told him I
was looking for plastigauge in a parts store, but they didn't even
know what it was.

He said he does not check clearances on new bearings when using new
cranks, or even when he has turned a crank himself and measures
journals. He says bearings, and new cranks, are the nominal size the
mfg says they are, to a perfectly adequate precision, not like years
ago. He says measurement capability and machining operations are much
improved today.

On Sat, 2 Aug 2008 09:53:07 -0500, "Robert Swinney"
wrote:

Bernie wrote: "During the Civil War,
every citizen soldier had his own musket, each of a slightly different
caliber, so they had to cast their own bullets, and repairing them was
difficult due to lack of interchangeability. Mass manufacturing
methods not that long afterwards resulted in rifles being crafted in
great numbers with precision, which drove the cost down and the
deadliness of warfare up."

Buncha crap, Bernie. Muskets and ammunition were mass produced during the civil war period. I read
your post with some interest until I got to that part. It totally denigrated anything else you had
to say. The "one bad apple in the barrel thing", don't you know.

Bob Swinney

Bob..many State Militia groups brought their own weapons, from
repeaters to Enfields.

While its indeed true that the Springfield was the Standard arm...

Bernies comments were more true about the Revolutionary war period
however...

Eli Whitney was the father of "weapons interchangability"

Gunner





"Carl M" wrote in message
...
On Aug 1, 8:28 pm, Christopher Tidy
wrote:
Hi folks,

This question came into my head a few days ago. I often hear people
suggesting that the latest vehicle engines last longer and are more
trouble-free than older engines. But I also hear people saying, just as
often, "They don't make them like they used to".

I was looking at a Dennis Z Type lawnmower a few days ago. I am hoping
to acquire one. For those who don't know, this is a legendary machine. I
think its engine is probably the best lawnmower engine ever made. It has
forced lubrication and an oil filter, complete with a passage for oil
through the crankshaft, and was introduced in 1922.

Now it's possible that one might look back at older products and view
them as being superior because all the poor quality products from the
era wore out and were replaced. It's also likely that the answer to the
question will depend on the type of engine you look at, and the quality
of construction. But I'll leave it as a general question, as I'm
interested to hear anyone's experience.

I get the impression that perhaps engine technology is moving in two
opposing directions. On the one hand, improving technology such as
better lubricants, filtration and bearing materials, are resulting in
components lasting longer. But on the other hand, the whole industry
appears to be moving towards less maintainable engines. Engines which
are wholly dependent on electronics, sometimes with coated rather than
lined cylinders. Engines which are difficult for anyone to maintain at
home. Perhaps this is why I don't hear people talk about replacing
piston rings, or having crankshafts regound anymore? Or perhaps these
parts last for the lifetime of the vehicle?

I'd be interested to hear people's opinions. I'd also be very interested
to see data comparing wear rates in modern and old engines, if anyone
knows where I can find such data.

Best wishes,

Chris Tidy


I tend to agree with you to some degree, however, as consumers our
expectations have gone up over the years. It wasn't that long ago
that cars were worn out at 20K miles, and that automobiles came with
instructions that told you how to repair the babbit bearings in the
engines yourself. Now, a car with 200K miles is normal, even barely
broken in. Machines made by craftsman who understood the fine details
of quality machinery were rare and highly sought after, as they had
under one hat engineering, design, assembly, and maintenance skills,
but they couldn't make them very fast or very cheap. Now these skills
are most commonly segregated to individuals, with less and less having
all those abilities at one time. Competition has ensured that quality
and endurance are important, as well as cost. Modern automotive
engines are designed and can be easily reproduced with tolerances
unattainable not that long ago, and the tight tolerances, combined
with carefully worked out assembly processes ensure that the cost
comes down with little to no loss in quality.
That said, all engineering design is a compromise. Quite often a
lower quality part is selected for a car or other machinery because it
keeps the cost down. Rarely do we notice these things, and when we
do, it's often a big deal. If money is not object, someone somewhere
will build you the machine you want with the very best components that
you want, but it will cost a lot of money, be hard to find parts for,
and only used by limited numbers of people. We as consumers also have
to make a compromise based on our needs, wants, and wallet, and while
I'd like to have a Bugatti in the driveway, I don't have the money or
a practical need for it. I just need a car I can rack up the miles on
with low maintenance (as compared to my Triumphs...) and do everything
else I need it to do.

** Posted from http://www.teranews.com **

"[L]iberals are afraid to state what they truly believe in, for to do so would result in even less votes than they currently receive. Their
methodology is to lie about their real agenda in the hopes of regaining power, at which point they will do whatever they damn well please. The problem is they have concealed and obfuscated for so long that, as a group, they themselves are no longer sure of their goals. They are a collection of wild-eyed splinter groups, all holding a grab-bag of dreams and wishes. Some want a Socialist, secular-humanist state, others the repeal of the Second Amendment. Some want same sex/different species marriage, others want voting rights for trees, fish, coal and bugs. Some want cradle to grave care and
complete subservience to the government nanny state, others want a culture that walks in lockstep and speaks only with intonations of political correctness. I view the American liberals in much the same way I view the competing factions of Islamic
fundamentalists. The latter hate each other to the core, and only join
forces to attack the US or Israel. The former hate themselves to the core, and only join forces to attack George Bush and conservatives." --Ron Marr

"Gunner Asch" wrote: Eli Whitney was the father of "weapons
interchangability"
^^^^^^^^^^^^^^^^^
Yeah. He invented the cotton gun.

I believe the elimination of lead from the gasoline has done a lot to
eliminate engine wear. (Except valve guides.)

On Sat, 02 Aug 2008 13:48:38 -0700, with neither quill nor qualm,
Gunner Asch quickly quoth:

Bob..many State Militia groups brought their own weapons, from
repeaters to Enfields.

While its indeed true that the Springfield was the Standard arm...

Bernies comments were more true about the Revolutionary war period
however...

I received copies of a dozen headlines in an email this morning. None
of us can figure out how these buffoons graduated high school and/or
college. Here's the text of a few relating to this thread offshoot:

1) Volunteers Search for Old Civil War Planes

2) Federal Agents Raid Gun Shop, Find Weapons


Eli Whitney was the father of "weapons interchangability"

One Atta Boy going his way!
Do what you feel in your heart to be right - for you'll be criticized
anyway. You'll be damned if you do, and damned if you don't.
-- Eleanor Roosevelt

"Gunner Asch" wrote in message
news

Eli Whitney was the father of "weapons interchangability"

Gunner


Here's the mother: (you gotta see this)

http://www.youtube.com/watch?v=bFVQYj_zk_M

Gunner Asch wrote in
news
On Sat, 2 Aug 2008 09:53:07 -0500, "Robert Swinney"
wrote:

Bernie wrote: "During the Civil War,
every citizen soldier had his own musket, each of a slightly different
caliber, so they had to cast their own bullets, and repairing them was
difficult due to lack of interchangeability. Mass manufacturing
methods not that long afterwards resulted in rifles being crafted in
great numbers with precision, which drove the cost down and the
deadliness of warfare up."

Buncha crap, Bernie. Muskets and ammunition were mass produced during
the civil war period. I read your post with some interest until I got
to that part. It totally denigrated anything else you had to say.
The "one bad apple in the barrel thing", don't you know.

Bob Swinney

Bob..many State Militia groups brought their own weapons, from
repeaters to Enfields.

While its indeed true that the Springfield was the Standard arm...

Bernies comments were more true about the Revolutionary war period
however...

Eli Whitney was the father of "weapons interchangability"

Gunner


In the US maybe, but he was 20 years behind, gasp, the french (Blanc) and
whitney never actually actually implemented or even designed a
manufacturing process capable of producing his guns with interchangeable
parts. He did show the need and did the congressional display entirely with
hand made parts.

"Leo Lichtman" wrote in news:9o4lk.283436
:

I believe the elimination of lead from the gasoline has done a lot to
eliminate engine wear. (Except valve guides.)




I don't think that has had much, if anything to do with it. Lead actually
acts as a lubricant. The advancement of materials, super precise CNC
controlled machines that allow tighter tolerances and features that were
not possible before, considerable strides in tooling, along with the
massive advancement of Design tools such as CAD, FEA, sensors, data
aquisition systems, etc. has had the most effect.

--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

Don Stauffer in Minnesota wrote:

He said he does not check clearances on new bearings when using new
cranks, or even when he has turned a crank himself and measures
journals. He says bearings, and new cranks, are the nominal size the
mfg says they are, to a perfectly adequate precision, not like years
ago.


Trust but verify. All it takes is a bit of crud under the bearing shell to ruin your day.

Wes

Leo Lichtman wrote:
I believe the elimination of lead from the gasoline has done a lot to
eliminate engine wear. (Except valve guides.)


I believe you are right. Especially concerning bore wear.

On Sat, 02 Aug 2008 21:26:31 GMT, "Leo Lichtman"
wrote:


"Gunner Asch" wrote: Eli Whitney was the father of "weapons
interchangability"
^^^^^^^^^^^^^^^^^
Yeah. He invented the cotton gun.

And the Red Herring.

Humm...or was that Lenin....?

No matter....


http://www.eliwhitney.org/arms.htm



Gunner

"[L]iberals are afraid to state what they truly believe in, for to do so would result in even less votes than they currently receive. Their
methodology is to lie about their real agenda in the hopes of regaining power, at which point they will do whatever they damn well please. The problem is they have concealed and obfuscated for so long that, as a group, they themselves are no longer sure of their goals. They are a collection of wild-eyed splinter groups, all holding a grab-bag of dreams and wishes. Some want a Socialist, secular-humanist state, others the repeal of the Second Amendment. Some want same sex/different species marriage, others want voting rights for trees, fish, coal and bugs. Some want cradle to grave care and
complete subservience to the government nanny state, others want a culture that walks in lockstep and speaks only with intonations of political correctness. I view the American liberals in much the same way I view the competing factions of Islamic
fundamentalists. The latter hate each other to the core, and only join
forces to attack the US or Israel. The former hate themselves to the core, and only join forces to attack George Bush and conservatives." --Ron Marr

On Sat, 02 Aug 2008 22:31:13 GMT, Jerry wrote:

Gunner Asch wrote in
news
On Sat, 2 Aug 2008 09:53:07 -0500, "Robert Swinney"
wrote:

Bernie wrote: "During the Civil War,
every citizen soldier had his own musket, each of a slightly different
caliber, so they had to cast their own bullets, and repairing them was
difficult due to lack of interchangeability. Mass manufacturing
methods not that long afterwards resulted in rifles being crafted in
great numbers with precision, which drove the cost down and the
deadliness of warfare up."

Buncha crap, Bernie. Muskets and ammunition were mass produced during
the civil war period. I read your post with some interest until I got
to that part. It totally denigrated anything else you had to say.
The "one bad apple in the barrel thing", don't you know.

Bob Swinney

Bob..many State Militia groups brought their own weapons, from
repeaters to Enfields.

While its indeed true that the Springfield was the Standard arm...

Bernies comments were more true about the Revolutionary war period
however...

Eli Whitney was the father of "weapons interchangability"

Gunner


In the US maybe, but he was 20 years behind, gasp, the french (Blanc) and
whitney never actually actually implemented or even designed a
manufacturing process capable of producing his guns with interchangeable
parts. He did show the need and did the congressional display entirely with
hand made parts.

http://www.eliwhitney.org/arms.htm


http://www.eliwhitney.org/arms.htm#1


Gunner

"[L]iberals are afraid to state what they truly believe in, for to do so would result in even less votes than they currently receive. Their
methodology is to lie about their real agenda in the hopes of regaining power, at which point they will do whatever they damn well please. The problem is they have concealed and obfuscated for so long that, as a group, they themselves are no longer sure of their goals. They are a collection of wild-eyed splinter groups, all holding a grab-bag of dreams and wishes. Some want a Socialist, secular-humanist state, others the repeal of the Second Amendment. Some want same sex/different species marriage, others want voting rights for trees, fish, coal and bugs. Some want cradle to grave care and
complete subservience to the government nanny state, others want a culture that walks in lockstep and speaks only with intonations of political correctness. I view the American liberals in much the same way I view the competing factions of Islamic
fundamentalists. The latter hate each other to the core, and only join
forces to attack the US or Israel. The former hate themselves to the core, and only join forces to attack George Bush and conservatives." --Ron Marr

On Sat, 02 Aug 2008 21:26:31 GMT, "Leo Lichtman"
wrote:


"Gunner Asch" wrote: Eli Whitney was the father of "weapons
interchangability"
^^^^^^^^^^^^^^^^^
Yeah. He invented the cotton gun.


Actually he also invented interchangeable parts. See
http://www.eliwhitney.org/inventor.htm for details.

"It was Whitney's idea to make all the parts of his rifles so nearly
identical that the machines parts could be interchangeable from one
gun to another. "

Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)

On Sat, 02 Aug 2008 20:22:48 -0500, Steve Austin
wrote:

Leo Lichtman wrote:
I believe the elimination of lead from the gasoline has done a lot to
eliminate engine wear. (Except valve guides.)


I believe you are right. Especially concerning bore wear.

Actually lead cushions the valve face's contact with its seat. See any
reference to using unleaded fuel. the criteria is hard valve seats.


Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)

Bruce in Bangkok wrote:

Actually lead cushions the valve face's contact with its seat. See any
reference to using unleaded fuel. the criteria is hard valve seats.


I think we came out a head on that one. The cure for no lead made for a more durable
valve system.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

On Sun, 03 Aug 2008 06:07:59 -0400, with neither quill nor qualm, Wes
quickly quoth:

Bruce in Bangkok wrote:

Actually lead cushions the valve face's contact with its seat. See any
reference to using unleaded fuel. the criteria is hard valve seats.

(Right you are, Bruce. Lead cushioned metal parts, I don't believe it
caused any wear.)


I think we came out a head on that one. The cure for no lead made for a more durable
valve system.

Perhaps in one way. But the pollution from MTBE, lead's old
replacement, is still gumming up the works badly.
Do what you feel in your heart to be right - for you'll be criticized
anyway. You'll be damned if you do, and damned if you don't.
-- Eleanor Roosevelt

Larry Jaques wrote:


Perhaps in one way. But the pollution from MTBE, lead's old
replacement, is still gumming up the works badly.

And using food to make alky as a replacement oxyginate hasn't been so wonderful either.

Wes

"Larry Jaques" wrote in message
...

Perhaps in one way. But the pollution from MTBE, lead's old
replacement, is still gumming up the works badly.


MTBE was not a replacement for lead. It was a fraudulent government
mandated additive to oxygenate the fuel. It was highly toxic, and actually
lowered fuel economy to the point where more fuel was burned and that wiped
out the intended environmental benefit that the idiot do-gooders sought to
solve in the first place.

Lead was used as an octane booster and was selected not for its incidental
lubricity, but rather because it was the cheapest thing out there to boost
the octane.

--
Roger Shoaf
If you are not part of the solution, you are not dissolved in the solvent.

"Roger Shoaf" wrote: (MTBE) was highly toxic, and actually
lowered fuel economy to the point where more fuel was burned and that
wiped
out the intended environmental benefit that the idiot do-gooders sought to
solve in the first place. (clip)
^^^^^^^^^^^^^^^^^^^
It was also very prone to leak from the underground tanks. It invaded the
water supply in many areas, and has been very hard to remove.

On Sun, 03 Aug 2008 12:05:17 -0400, with neither quill nor qualm, Wes
quickly quoth:

Larry Jaques wrote:


Perhaps in one way. But the pollution from MTBE, lead's old
replacement, is still gumming up the works badly.

And using food to make alky as a replacement oxyginate hasn't been so wonderful either.

At least the lead killed the in-tank bacteria and didn't pick up water
to rust or freeze in your fuel lines/tanks.

--
Do what you feel in your heart to be right - for you'll be criticized
anyway. You'll be damned if you do, and damned if you don't.
-- Eleanor Roosevelt

On Sun, 3 Aug 2008 10:38:52 -0700, with neither quill nor qualm,
"Roger Shoaf" quickly quoth:


"Larry Jaques" wrote in message
.. .

Perhaps in one way. But the pollution from MTBE, lead's old
replacement, is still gumming up the works badly.


MTBE was not a replacement for lead.

It is both an octane booster and oxygenate according to the Wiki
article.


It was a fraudulent government
mandated additive to oxygenate the fuel. It was highly toxic, and actually
lowered fuel economy to the point where more fuel was burned and that wiped
out the intended environmental benefit that the idiot do-gooders sought to
solve in the first place.

Indeed, and now, with $4+/gallon fuel, it's really costing us. DAMN!


Lead was used as an octane booster and was selected not for its incidental
lubricity, but rather because it was the cheapest thing out there to boost
the octane.

Right, the lubricity was incidental.

--
Do what you feel in your heart to be right - for you'll be criticized
anyway. You'll be damned if you do, and damned if you don't.
-- Eleanor Roosevelt

Larry Jaques wrote:
On Sun, 03 Aug 2008 12:05:17 -0400, with neither quill nor qualm,
Wes quickly quoth:

Larry Jaques wrote:

Perhaps in one way. But the pollution from MTBE, lead's old
replacement, is still gumming up the works badly.
And using food to make alky as a replacement oxyginate hasn't
been so wonderful either.

At least the lead killed the in-tank bacteria and didn't pick up
water to rust or freeze in your fuel lines/tanks.

Since Wisconsin has required up to 10% alcohol in gas sold in the SE
corner of the state, gas line antifreeze is no longer necessary. The
alcohol combines with the water and keeps it from freezing. Maybe
chemistry is different where you live.

Of course, the alcohol cuts gas mileage 10-20% and we pay extra for it...

David

William Noble wrote:
"Christopher Tidy" wrote in message
...

Hi folks,

This question came into my head a few days ago. I often hear people
suggesting that the latest vehicle engines last longer and are more
trouble-free than older engines. But I also hear people saying, just as
often, "They don't make them like they used to".




short answer, "yes", at least for automotive use. I have 1936, 1938, 1951,
1959, 1985, 1986, 1993, 1997, and 2001 vehicles under my purview. up
through the 51 year car, 150K miles or so was the limit - at that point the
bores were 40 to 60 over, rings shot, no compression, crank oval, no oil
pressure, etc. 59 is good for 200K easy. there was a major change in the
metalurgy of the engine block, etc, as I understand it - we can debate what
changed, but the longevity is just not an issue.

Thanks for sharing your experience, William. If any designers out there
know of significant changes in car engine block metallurgy over the last
50 years or so, and are able to share them, I would be very interested
to hear.

I'm under the impression that cast iron blocks and/or cast iron cylinder
liners were the norm in the 1950s, and that cast iron liners still are
today, but I could be wrong. There have been some engines which use
coated aluminium cylinders, but after the Nikasil and sulphur problems
in the 1990s, I thought they were in decline.

Best wishes,

Chris

Christopher Tidy wrote:
William Noble wrote:
"Christopher Tidy" wrote in message
...

Hi folks,

This question came into my head a few days ago. I often hear people
suggesting that the latest vehicle engines last longer and are more
trouble-free than older engines. But I also hear people saying, just
as often, "They don't make them like they used to".




short answer, "yes", at least for automotive use. I have 1936, 1938,
1951, 1959, 1985, 1986, 1993, 1997, and 2001 vehicles under my
purview. up through the 51 year car, 150K miles or so was the limit
- at that point the bores were 40 to 60 over, rings shot, no
compression, crank oval, no oil pressure, etc. 59 is good for 200K
easy. there was a major change in the metalurgy of the engine block,
etc, as I understand it - we can debate what changed, but the
longevity is just not an issue.

Thanks for sharing your experience, William. If any designers out
there know of significant changes in car engine block metallurgy over
the last 50 years or so, and are able to share them, I would be very
interested to hear.

I'm under the impression that cast iron blocks and/or cast iron
cylinder liners were the norm in the 1950s, and that cast iron liners
still are today, but I could be wrong. There have been some engines
which use coated aluminium cylinders, but after the Nikasil and
sulphur problems in the 1990s, I thought they were in decline.

Best wishes,

Chris

Chris,

I am not sure of the specifics but there is cast iron and cast iron, it
varies dramatically depending on composition, application and how the
part is produced. IIRC Ford used a higher chrome CI in casting some 302
block for high spec applications in the 60s to reduce wear. I am not
sure but would expect iron liners could be produced with far better wear
characteristics than a CI parent metal bore but also at high price. Not
neccessarily applicable to CI but a mate that works for Ricardo has
mentioned on a number of occasions that specialist foundries do the
likes of aluminium heads as control of dendrite size and orientation is
critical to the success of the head. IIRC the dendrite formation is
controlled so the highest strength characteristics are at the head to
block face.

Christopher Tidy wrote:
William Noble wrote:
"Christopher Tidy" wrote in message
...

Hi folks,

This question came into my head a few days ago. I often hear people
suggesting that the latest vehicle engines last longer and are more
trouble-free than older engines. But I also hear people saying, just
as often, "They don't make them like they used to".




short answer, "yes", at least for automotive use. I have 1936, 1938,
1951, 1959, 1985, 1986, 1993, 1997, and 2001 vehicles under my
purview. up through the 51 year car, 150K miles or so was the limit -
at that point the bores were 40 to 60 over, rings shot, no
compression, crank oval, no oil pressure, etc. 59 is good for 200K
easy. there was a major change in the metalurgy of the engine block,
etc, as I understand it - we can debate what changed, but the
longevity is just not an issue.

Thanks for sharing your experience, William. If any designers out there
know of significant changes in car engine block metallurgy over the last
50 years or so, and are able to share them, I would be very interested
to hear.

I'm under the impression that cast iron blocks and/or cast iron cylinder
liners were the norm in the 1950s, and that cast iron liners still are
today, but I could be wrong. There have been some engines which use
coated aluminium cylinders, but after the Nikasil and sulphur problems
in the 1990s, I thought they were in decline.

Best wishes,

Chris


Cast iron blocks have been around since day one of engine production.
However the iron alloys used today are FAR superior. It allows thinner
castings that have tighter grain patterns and through the use of newer
alloys the wear and machining characteristics are such that the blocks
made today last longer.

99% of the aluminum blocks use steel liners cast into the blocks. The
rest use a type of chrome plating of the cylinder walls. Most of them
are not built for long life though. Many are air cooled small engines.
Things like lawn mowers and weed eaters. The industrial/heavy duty ones
have iron or steel liners.

--
Steve W.
Near Cooperstown, New York

Don Stauffer in Minnesota wrote:
On Aug 2, 1:56 am, "William Noble" wrote:

"Christopher Tidy" wrote in message

...


Hi folks,

This question came into my head a few days ago. I often hear people
suggesting that the latest vehicle engines last longer and are more
trouble-free than older engines. But I also hear people saying, just as
often, "They don't make them like they used to".

short answer, "yes", at least for automotive use. I have 1936, 1938, 1951,
1959, 1985, 1986, 1993, 1997, and 2001 vehicles under my purview. up
through the 51 year car, 150K miles or so was the limit - at that point the
bores were 40 to 60 over, rings shot, no compression, crank oval, no oil
pressure, etc. 59 is good for 200K easy. there was a major change in the
metalurgy of the engine block, etc, as I understand it - we can debate what
changed, but the longevity is just not an issue

** Posted fromhttp://www.teranews.com**


In additions to metallurgical advances, there have also been major,
good changes in lubricating oil and manufacturing precision.

I was talking to a friend who runs an engine rebuilding business,
specializing in rebuilding antique and classic engines. I told him I
was looking for plastigauge in a parts store, but they didn't even
know what it was.

He said he does not check clearances on new bearings when using new
cranks, or even when he has turned a crank himself and measures
journals. He says bearings, and new cranks, are the nominal size the
mfg says they are, to a perfectly adequate precision, not like years
ago. He says measurement capability and machining operations are much
improved today.

I can see that improved precision will result in a longer service life,
provided that the surface finish is excellent. It's my understanding
that for a hydrodynamic bearing in which the bearing's length, radius,
rotational speed (for this, take the engine's idling speed) and
lubricant viscosity are fixed, the maximum allowable load is inversely
proportional to the radial clearance. So if the parts are very
close-fitting, they will likely be able to carry a greater load than
necessary when new, but the load they can carry without
surface-to-surface contact will fall as the clearance increases due to wear.

Provided that the surfaces are not touching (except when starting and
stopping), the wear rate will probably be at a minimum soon after the
bearing surfaces are new, and after that it will slowly rise. If you are
able to manufacture bearing surfaces with excellent precision and an
excellent surface finish, you prolong the period in which the bearing is
able to carry a greater load than is necessary, and prolong the period
in which the rate of wear is low. Eventually, the bearing will no longer
be able to support the load without the surfaces touching, and the wear
rate will rise dramatically.

Babbitt metal can probably be seen as a bearing material which develops
an excellent surface finish during the running-in period.

I imagine that multigrade oils reduce the wear rate at high temperatures
and increase engine efficiency at low temperatures. I am not certain
about the effect of oil additives. Do they work by adding a layer of
slippery graphite to the bearing surfaces, in the way that cast iron
does? Perhaps someone can explain?

Best wishes,

Chris