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#451 2020-12-02 17:57:51

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,054

Re: Housekeeping

For kbd512 and SpaceNut ...

Thanks to each of you for adding to this subtopic ...

On Earth, home owners (or apartment dwellers) are rarely totally dependent upon the machinery added to the dwelling to enhance the living experience.

On Mars, everyone ** will ** be totally dependent upon machinery.

In your comment, kbd512, I think you have pointed the way that future engineers must think for the early phase of Mars settlement.

Ultimately, the current practice we see on Earth, of mass production to bring price as low as possible to serve as many people as possible, may show up on Mars, but (on the other hand) the lethality of the machine environment on Mars, in space, and anywhere away from Earth may impel a higher level of performance of the engineering discipline.

For SpaceNut ... the points you have made about water quality seem (to me at least) to point toward a higher level of water quality certification on Mars, both for the individual habitation, and for any public service that may come into being.

In short, it seems to me reasonable to suppose that the catch-as-catch-can attitude we often see on Earth will not be tolerated on Mars, or anywhere else away from the Earth.

Eventually higher standards away from Earth may feed back into the Earth culture.

(th)

Last edited by tahanson43206 (2020-12-02 21:37:03)

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#452 2020-12-02 20:33:33

kbd512
Administrator
Registered: 2015-01-02
Posts: 6,240

Re: Housekeeping

tahanson43206,

A belief in the value of making machines with the best quality practical has to start on Earth, whereupon it will naturally transfer over to any other place humanity goes.  Humans already know perfectly well how to make most parts of a car last for at least a century, but most consumers refuse to spend the extra money on proper materials choices and machining and dimensional standards for parts.  Naturally, the automotive corporations would prefer you purchased a new car every few years.  However, their engineers wouldn't be designing engines that can run for five or even ten years prior to a major failure if they were completely disinterested in quality and durability.  I don't think it's a matter of bad engineering practices.  The engineers are doing what they've been directed to do- namely, a juggling act that attempts to balance the wants of their own corporation with that of the consumer and regulators while all three groups have divergent wants.

We presently design all-steel or mostly steel diesel engines that provide at least a million miles of service between major overhauls.  If we had reasonable power-to-weight ratio expectations of gasoline engines, then those engines could also last a million miles.  If anything, the electronics have improved the service lives of both types of engines.  There was a time in our history when all crankshafts and connecting rods were forgings, rather than castings or powdered metal.  The cast iron engine blocks had a high Nickel content, so they would develop surface rust or patina, but typically wouldn't corrode into uselessness unless they were left submerged in salt water.  Engineers are not dummies.  They know how to make durable and reliable machines, if they're permitted to select the materials and manufacturing processes that are conducive to that goal.

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#453 2020-12-02 22:12:38

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,054

Re: Housekeeping

for kbd512 re #452

Your post is internally consistent and it reads well, so I feel almost guilty pulling out a few words for comment ...

but most consumers refuse

I'm going to start by making the assumption you had to over simplify to try to pack a complex subject into a couple of paragraphs.

My sense is that it is to give too much credit to the average consumer, to imagine they are aware of materials that go into a product, or design considerations that govern the expected life.  However, I do sense that the average consumer does not check with Consumer Reports before buying a product.  Obviously enough do so that Consumer Reports stays in business.  i have a relative who subscribes, and it makes sense that his service lifetimes are better than the average. 

The global market may be large enough now (2020) to support a full range of offerings, carefully designed to live precise amounts of time at a particular price point, in competition with myriads of competitors.

For Mars, especially in the early survival days, I'm hoping the engineers will be asked to deliver the best possible systems achievable with current technology, and that the funders (government or private) will be willing to allocate the necessary resources.

However, I started this little subtopic with the observation that a piece of hybrid equipment (electronic systems packaged with mechanical ones) failed in a particularly dramatic and potentially lethal way.  i have no doubt the smoke from that device was toxic, so clearing the house immediately with winter air was a necessity.

A failure like that in a closed habitat would be far more serious.  In fact (come to think of it) something similar occurred on MIR, if I recall correctly.  I hope that engineers tasked with designing machinery for Mars (or anywhere away from Earth) will be given both the responsibility and the resources to anticipate such failure modes and prevent them.

A belief in the value of making machines with the best quality practical has to start on Earth, whereupon it will naturally transfer over to any other place humanity goes.

I like the sentiment in that statement, but worry that that "natural transfer" depends upon education and training, and longevity of old hands.  Many many science fiction writers have studied human fallibility in this specific area, and while I've (of course) read only a minuscule fraction of what's been written, I've read enough to have a healthy respect for the sheer power of entropy in this area.

I came to this forum from Dr. Dartnell's Knowledge forum.  The theme there revolves around the fragile nature of the ever moving mental matrix of ultra specialized human talents and skills that supports our economy.  To over simplify and exaggerate to a ridiculous degree, it may take as many as a million separate steps to make a modern pencil.

A reason that the Knowledge forum is languishing may be that a person who actually tries to comprehend the fragility of the billions of balls we are simultaneously juggling will become depressed.

At least with the Mars venture, it seems to me there is a sense of optimism that we'll keep all those balls in the air long enough to start them bouncing in another location than Earth.

For that reason (among many) I appreciate your sense of optimism.

SearchTerm:Quality in design of machines

http://newmars.com/forums/viewtopic.php … 93#p174493

(th)

Last edited by tahanson43206 (2020-12-02 22:14:43)

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#454 2020-12-03 11:53:17

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,054

Re: Housekeeping

For SpaceNut re ID recovery ... 397-418 are ready for unbanning.

Let's start thinking about how to recruit new, high value members.

I'm thinking of "high value" as those who contribute at least as much as they receive from the forum.

This forum is blessed with a number of PhD level members.

That is a fragile and perishable resource.

We need younger members and we ** especially ** need those who can imagine themselves actually walking on Mars in ten or twenty Earth years.

Thanks to your command decision to cut off the incessant flow of spam ID's, we have an opportunity to make sure we actually ** know ** the person we are inviting to participate in the forum.

Anonymity can be preserved for those who do not wish to be identified to the global audience, but it seems essential (to me at least) for each new member to be vetted so that there is a sense of the contribution they can make, and their ability and willingness to actually deliver on the promise.

The FluxBB forum software does not lend itself to easily accessible retrieval of knowledge, but careful design of posts can increase chances the investment made by a member in recording knowledge or best practice will be accessible to others in future.

(th)

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#455 2020-12-03 17:30:05

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 26,798

Re: Housekeeping

There is one more reason for longevity issue of manufactured goods as corporate greed comes to make an item cheaper by changing materials, or item design shape to use less material and to change a process on made materials.

Still on cellphone mode for a few more days but will do my best to do the unbannings while commenting.

There appears to be a duplicate.

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#456 2020-12-03 18:21:39

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,054

Re: Housekeeping

For SpaceNut re duplicate .... thanks for catching that!

I am still learning how to work with FluxBB for this project!

My working assumption had been that the system would tell me if I made a duplicate ID, but it did not.

Instead, it appended the letter 'a' to the ID and saved it without "saying" anything about the substitution.

TestiD00379a
TestiD00421

The duplicate was converted to fit into tomorrow's run. 

Interesting.

Also ... thanks for trying to view the video's as they come up.

I'm looking forward to the one on Engineering a rover.  The challenges faced, and the solutions found, will surely guide engineers as they continue designing equipment for Mars.

In another topic, kbd512 recently commented upon "quality" in design.  Nature has a way of enforcing a high standard for design.

(th)

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#457 2020-12-03 21:11:52

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 26,798

Re: Housekeeping

Originally it was missing the I in the name and when I went to save it the software indicate that it was a duplicate so I put the a on the end to save it.

I gave those topics a bump.

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#458 2020-12-03 23:02:21

kbd512
Administrator
Registered: 2015-01-02
Posts: 6,240

Re: Housekeeping

tahanson43206,

It always comes down to how much you want to spend to achieve a given result, along with how much weight and/or inefficiency is tolerable.

Engines that achieve fantastically high outputs from tiny displacements are always living on borrowed time.  The F1 engines that achieve 500hp/L have lifespans measured in hours.  Rocket engines have lifespans measured in minutes.  A single cylinder low-speed diesel can run for decades on end without stopping for maintenance.  It'll have an exceptionally low output, given its weight, but that modest power-to-weight ratio is what provides ultimate durability and longevity in operation.

The same will be true of life support systems or chemical refining systems that achieve fantastic temperatures, pressures, and/or efficiencies.  A true cost-benefit analysis would carefully weigh all trade-offs associated with bleeding edge performance.

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#459 2020-12-04 07:24:41

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,054

Re: Housekeeping

For kbd512 re #158 and market economic decisions

Your opening sentence captures an important segment of the population, bearing in mind that an individual can move between categories.

Yesterday, I visited a local big box store to find a replacement for the defunct microwave.  I paid close attention to my thought process, and I also paid attention to the comments of another shopper who was on what sounded like an identical mission.  We'd both had microwaves that lasted far beyond their warranty.

We ended up buying exactly the same product, from a range of microwaves that included a $50 minimal dorm room coffee warmer to the top of the line over-the-oven model that was close to $300.  At no time did I think about the materials inside the unit.  I did think about the outer appearance of each model, and the power of the magnetron, the convenience of mechanical operations, and the capability of the control system.

In the market system we have available today, it was clear that design teams were driven by a desire to try to build the best product they could at the many price points on display.  In every case, considerable effort was invested in trying to make the package visually appealing.

One interesting variation was a category that offered a "retro" look, featuring an appearance that reminded me of the first microwaves to reach the market. I hope these had better electronics, but was not inspired to find out.

From the standpoint of the consumer, design for safe failure is not something visible or even discoverable by reading the product literature.

It is ultimately the responsibility of the designer to think about such matters, while trying to juggle the demands of the marketing department, the product liability department and whatever other forces are at work in the modern large corporation.

I appreciate your focus on engines, because those are a significant part of the future, whether on Earth, heading to Mars, or on Mars.

In the case of kitchen appliances, it seems to me that for the Mars environment in particular, basic functionality needs to be balanced by a significant investment of time and thought about safety in an enclosed environment. 

(th)

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#460 2020-12-04 19:31:13

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,054

Re: Housekeeping

For SpaceNut re ID's review...

As this initiative moves along, from time to time a member will appear in the list ...

The most recent is:

Username
=VT=

User activity
Registered: 2006-05-25 (0.0.0.0)

Last post: 2006-09-27 14:46:32

Last visit: 2006-10-28 21:39:37

Posts: 6 - Show all topics - Show all posts - Show all subscriptions

It's been over 14 years since the last visit.

A lot could have happened since 2006.

Edit #1: Here's a more recent registrant ...

Username
a regular idiot

User activity
Registered: 2012-01-01 (98.254.105.111)

Last post: 2012-01-01 02:15:05

Last visit: 2012-01-01 02:15:05

Posts: 1 - Show all topics - Show all posts - Show all subscriptions

This person's single post was about bringing soil back from Mars to use as a basis for plant growth experiments.

According to FluxBB, that one post generated 12 replies.

Edit#2 .... A.B.Bell only posted once, but that post stimulated quite a bit of interest.

http://newmars.com/forums/viewtopic.php … 68#p128468

Edit #3: This user was active between 2002 and 2005.

Username
A.J.Armitage

User activity
Registered: 2002-05-30 (0.0.0.0)

Last post: 2005-02-16 03:02:42

Last visit: 1969-12-31 20:00:00

Posts: 239 - Show all topics - Show all posts - Show all subscriptions

A curiosity is the "last visit" date, which may have been altered as a result of the "Great Crash"

Edit #4: Here is a member with four posts:


Username
a1call

User activity
Registered: 2007-06-24 (0.0.0.0)

Last post: 2007-06-25 18:07:09

Last visit: 2007-06-25 19:09:48

Posts: 4 - Show all topics - Show all posts - Show all subscriptions



(th)

Last edited by tahanson43206 (2020-12-04 21:58:12)

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#461 2020-12-04 21:55:30

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,054

Re: Housekeeping

SpaceNut, please take a look at this User ID: Aa Seat Assignment

The record was created in 2018, but nothing was ever posted.

ID's 419-440 are ready for unbanning.

(th)

Last edited by tahanson43206 (2020-12-04 22:06:02)

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#462 2020-12-05 08:21:50

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,054

Re: Housekeeping

For SpaceNut .... the ID review has moved out of the numeric range, where most ID's were banned.

In the alphabetic range, there are an increasing proportion of members.

The latest I found posted one message to a topic I have not visited before: Index» Intelligent Alien Life» The purpose of this forum

It was interesting (to me at least) to see how Adrian dealt with this subject matter back in 2002. 

Username: aaron

User activity
Registered: 2006-09-02 (0.0.0.0)
Last post: 2006-09-02 16:14:03
Last visit: 2006-09-02 16:10:11
Posts: 1 - Show all topics - Show all posts - Show all subscriptions

Edit#1:
Username: Aaron Chester

User activity
Registered: 2002-02-28 (0.0.0.0)
Last post: 2002-05-23 16:31:27
Last visit: 1969-12-31 20:00:00
Posts: 18 - Show all topics - Show all posts - Show all subscriptions

Most of the 18 posts appeared in Human Missions topics

*** For SpaceNut ... please take a look at this ID: AaronPoult
No posts and mismatch between email and ID

ID's 441-462 are ready for unbanning

(th)

Last edited by tahanson43206 (2020-12-05 09:02:29)

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#463 2020-12-05 09:09:13

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 26,798

Re: Housekeeping

Computer still not up for online use as tethering account has not reset to allow for its use.

Will take care of the unbannings but the remaking will need to wait a few days.


There was a request a long time ago to do a reach out Email campaign to see which accounts to close based on lack of the respondents verification. This something that should happen in conjunction with all other outreach we are doing.

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#464 2020-12-05 09:20:43

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,054

Re: Housekeeping

For SpaceNut ... thanks for taking care of as much as you can.

Hopefully the faster service will free up soon!

***
I like the idea of an email outreach effort.  It could be done one-by-one, using NewMarsMember account.  That account has a gmail email, and it could be set up to notify someone if email arrives.  I'm thinking about setting up a dedicated system just to monitor that email account.  I have too many balls in the air at the moment, but the hardware is available.

(th)

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#465 2020-12-05 14:44:31

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 26,798

Re: Housekeeping

Currently I am expecting a nor Easter that could mean power outages by Sunday as the wind picks up. We currently have wet snow falling with about 4 inches already on the ground.

Update at 17:50 as initial post was almost 3 hrs ago

Its now raining heavily

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#466 2020-12-05 15:16:15

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,054

Re: Housekeeping

For SpaceNut re #465

Best wishes to come through the weather event without an outage or damage. 

The weather channel gave a mini-seminar on snow types last night, as they covered projections for your area.

I had not realized the range of ratio of water to volume in various kinds of snow.  Your area is apparently expecting a snowfall with a ratio on the order of 1:7. The very best possible snow in alpine skiing country may have a ratio as high as 1:30 or more.

(th)

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#467 2020-12-05 16:07:09

kbd512
Administrator
Registered: 2015-01-02
Posts: 6,240

Re: Housekeeping

tahanson43206,

Apologies for the long post, but…

One point to consider is that modern solid state electronics with premium components provide a level of reliability / durability wildly beyond their analog counterparts, in most cases.  If the absolute best quality environmentally hardened electronics were used, then it's nearly a mathematical certainty that all of the mechanical components in the engine would require several refurbishments or replacements before the engine stops due to computer failure.

Engines with computer controls can obviously fail in ways that analog components cannot, but generally speaking, computer control prevents or drastically reduces the aberrant operating conditions that typically caused the premature demise of analog engines.  When electronics were first used to control combustion engines, the designers didn't fully appreciate the severity of the environment that the electronics were being asked to operate in.  Quite frankly, the materials and fabrication methods weren't as good as they are today.  These days, all of those issues have been ironed out.  The result is that the electronics, while a pain to work with for those who don't know how they function, are primarily responsible for much of the increased engine life seen in typical vehicles.

The machining tolerances of mechanical components, application-specific aerospace coatings, and lubricants have all improved along the way, but most of the factory engines are now constructed as cheaply as possible (cast crankshafts, powdered metal connecting rods, plastic oil pans and valve covers) while managing to survive power output levels and duty cycles that would've destroyed carbureted engines constructed with better quality materials and methods (forged crankshafts and connecting rods, sheet steel oil pans and valve covers).  The advent of billet CNC machined micro-shot-peened (WPC treatment) components has taken dimensional accuracy and resistance to fatigue cracking to another level, with the end result being that proper component selection allows engines to reliably operate at 1hp per cubic inch of displacement for hundreds of hours.

A man by the name of Gale Banks finally cracked the code of explaining boosted engine operation to shade tree mechanics.  Basically, he teaches people that manifold air density and temperature are what determine power output.  Some number of pounds of air are required to completely combust a given number of pounds of fuel, which determines an engine's horsepower output, provided that all components can survive any power increases; and that a boost gauge is utterly meaningless in this regard.  The engineers knew that all along, but he explains that quite well in layman's terms with pictorial examples.  These days you see a lot fewer people with diesel trucks blowing black smoke because now they realize that, in addition to wasting fuel, they're also damaging a very expensive engine.  None of his engines smoke at all, because nearly all of the fuel is being combusted in the combustion chamber.  The modern computer-controlled ultra-high pressure common rail fuel delivery systems completely atomize the fuel to increase the surface area of the fuel mist / droplets in contact with the air intake charge in the cylinder, reducing emissions and increasing power output while keeping internal temperatures in check.  He's done simple but profound things like improving the geometry of intake pipes to reduce the force / turbo back-pressure required to compress a given volume of air.

Banks used GM's new L5P DuraMax, which comes significantly over-built for its stock power level from the factory, to make over 1,000hp by swapping in a greater duration cam, injectors flowing more fuel, after-cooling, and a bigger turbo to cram in more air.  The stock everything was good enough for about 800hp.  It won't survive that power level for a long time without billet everything and cast iron heads, but he didn't damage the engine, either.  With billet crank / main caps / rods / cam, steel pistons, cast iron heads, and ARP stud kit, it could become a suitable semi truck engine at 1/3rd the weight of a caterpillar C15 ACERT.  Not saying it would last as long as the big Cat, but it could probably survive a half million miles or so at 600hp.  If GM upgraded to a stronger CGI (Compacted Graphitic Iron) block, it could conceivably survive for a million miles or so.  Truckers are partial to their big I6s, so it might take some convincing to get them to switch to a more efficient and lighter engine.  To truly survive at 600hp, we're talking about a $40,000 twin-turbo engine, but it would weigh about 1,000 pounds vs the Cat C15 at 3,600 pounds.  A purpose built pickup truck of perhaps 12,000 pounds should be sufficient to haul a fully loaded trailer.  The Mack Anthem Class 8 semi-trucks are $100,000 to $140,000 or so and weigh 28,000 to 32,000 pounds.  The stock L5P DuraMax produces equivalent horsepower and torque to Mack’s big MP I6 diesel, so we would massively beef up the L5P, produce a bit more horsepower and torque (100hp to 150hp more than the Mack) with a LOT less weight and fuel burn associated pulling that excessive weight of Mack’s much heavier Anthem semi truck.

In the aviation world, Mike Busch has been teaching the same thing that Gale Banks has been.  His personal belief is that all aircraft engines should be boosted and operated over-square (high manifold pressure, low-rpm)- the wisdom of that technique was eventually understood from experience in WWII as the best way to run a powerful boosted Allison or Merlin aircraft engine to maximize its service life, and that manifold air pressure and inlet temperature are what a pilot should really pay attention to.  A few of the better CFIs will teach their students to correlate manifold pressure changes with power setting changes, such that they run the engine based upon manifold air pressure, somewhat similar to how you'd operate a gas turbine engine.

My own CFI always harped on setting the power level to a given number of inches of intake manifold air pressure and then making sure that the prop wasn't driving the engine rpm (over-speeding from an incorrect power or pitch setting).  He basically said, "Well, kbd, you already know the red line for this engine, so obviously don't exceed that unless you want to pay for a teardown inspection, and don't let that prop drive the engine, but otherwise pay attention to the MAP."  It's fundamentally very easy to understand because it's so directly tied to the way all suck-squeeze-bang-blow engines work.

The pilots in WWII were worried about high manifold pressures damaging their engines because they were fundamentally ignorant of how they worked.  Pilots should care about manifold temperature on a boosted engine because the combination of pressure and temperature is what equates to intake charge air density and therefore weight to combust, which is what Banks is telling everyone smart enough to listen (he didn't come up with anything except simple ways to explain basic physics), but high manifold pressure is a very good thing to have.  The ignition event instantaneously raises the pressure in the cylinder to thousands of bars, whereas the manifold pressure is a paltry fraction of the ignition (combustion) pressures.  In short, each ignition event is a hammer blow to the crank pins and other parts of the rotating assembly, as compared to what simply "running the air pump" is doing to that assembly.  So, a better question to ask yourself is how the hell are you supposed to make good power if you have a near vacuum in your cylinders (low manifold pressure)?  Well, that's easy...  You can't, because that's impossible.  You need oxygen to combust fuel.  If the oxygen ain't there because you have low intake manifold pressure, then you can't make good power, period and end of story.  You're essentially blowing fuel out the exhaust, or worse, back through the intake manifold on the upstroke of the piston if your valves aren't fully shut as the rotating crank pin starts forcing the piston back up through the cylinder bore.

High RPM, on the other hand, is what ultimately causes faster fatigue failure of the rotating assembly components.  The forces don't increase linearly with RPM, either.  Double the RPM and the forces acting on the rotating assembly don't merely double, they quadruple.  That was what killed Allisons and Merlins faster.  For any kind of acceptable service life, especially due to torque reversals, the cast Aluminum pistons can only tolerate a mean free piston speed of about 3,000 linear feet per minute.  Whenever you go significantly over that figure, service life of the rotating assembly is compromised.  The Allison and Merlin engines were essentially using "stroker cranks" in them with very long strokes (good for power, but bad for piston and connecting rod service life), which means they had a high mean free piston speed, even at a seemingly modest 2,500 to 3,000 rpm, and of course machining tolerances and process control back in WWII were nowhere near as good as they are today with our multi-axis CNC machines and automated measurement devices.  The Brits hand-built their Merlins, whereas Packard made their Merlins using very accurate gauges and they were willing to reject / scrap non-conforming parts.  Both approaches were geared towards the strengths of the corporations involved.  The Brits employed master craftsman with months or even years of training, but the Americans had tools and processes and materiel for mass production using semi-skilled labor.  We could afford to scrap parts, but the Brits couldn't.

The modern medium and high rpm diesels use steel pistons rather than Aluminum for this reason, namely resemblance in operation to WWII aircraft engines with their high volumetric horsepower output and high continuous power output or duty cycle.  CNC production automation lowered parts rejection rates so manufacturers could easily afford the scrap rate and employ semi-skilled labor.  The long strokes and heat from high volumetric output cause rapid fatigue failure of Aluminum.  The low speed diesels on ships use steel pistons because the inertia from a slightly heavier steel piston is less of a problem at lower rpms.  You can also design a steel piston that is almost identical in weight to its Aluminum analog, but with a much better fatigue service life, though steel is also much harder to keep cool at high volumetric horsepower levels, as compared to Aluminum.  Everything is a compromise.

The NHRA nitro methane drag racers and top tier diesel drag racers uses long strokes and big fat Aluminum connecting rods and pistons to cushion the hammer blows to the crank pins, by deflecting a little bit on the power stroke, as the motor spins to 11,000 rpm for a few seconds, cramming so much fuel into the cylinder that the engine is nearly hydro-locked at the moment of ignition.  These all-Aluminum big blocks can make 10,000 hp by doing that, but the lifespan of the rotating assembly is measured in seconds to a handful of minutes.  Everyone racing at this level has serious money into their engines and vehicle designs, so tossing a set of billet Aluminum rods and pistons after a couple of passes is no big deal.

The F1 engines may rev to 18,000rpm, but they have 2" stroke lengths vs the 5" to 6" stroke lengths in the NHRA engines.  Even so, their lifespan is measured in hours.  Stock cars have 3" stroke lengths and rev to 8,000rpm or so.  All of the normally aspirated race engine designs run on standard gasoline make 600hp to 800hp with nearly identical piston speeds, but very different bore / stroke combinations.  The mean free piston speed in all cases is well over 3,000fpm (like 3,600fpm), but it's wildly over 3,000fpm in the NHRA nitro methane engines (up to 11,000fpm).  Now you know why those components don't survive more than one event, sometimes more than one pass.  In all cases except stock car racing, where they really should change the rules, they're allowed to boost the piss out of the engine to allow it to make as much power as it can from a given displacement.  The heads and intake manifold will try to separate from the top of the engine, but high strength studs / washers / nuts, rather than weaker bolts, along with sufficient pre-load, and torque-to-yield torque specs, ensure that the parts remain firmly clamped together unless you exceed the yield strength of the studs (and they do this in NHRA more than any other type of racing).  They also have studded main caps and girdles to tie all the main caps together, along with structural oil pans.  The engine is itself a stressed chassis component in F1 racing.  In many ways, F1 pushes technology to the limits more than any other motor sport.  They push materials and basic designs to their limits more in NHRA and Baja racing.  To be sure, there's a lot of envelope expanding going on in all forms of racing.  In the Reno Air Race unlimited class, you have nominally 1,500hp Merlins cranking out 4,000hp or more using special high-octane fuels that they blend small batches of for that specific purpose (air racing).  The reason the air race is so short is that the engines won't tolerate more than a few laps of that before overheating.  Even then, many of the engines overheat before finishing the race.

Long story short, if you want continuous high power output, then you want lots of manifold air density as Gale Banks calls it (typically helped quite a bit by using supercharging or turbocharging and inter-cooling or after-cooling to densify the air after compression heats it up) and high-RPMs with very short crank throws (crank pins with as much overlap with the main journals as you can manage, to avoid crankshaft and con rod flex and piston fatigue failures).  BTW, did I mention that you have to remove enough heat from exhaust valves if you operate at high power output continuously?  That’s another major problem with high volumetric power output.  If you want absurd amounts of power for a very short period of time, as in drag racing, then you want longer crank throws (a "stroker" crankshaft) to produce more torque across the entire RPM range.  If you want ultimate durability, then the entire rotating assembly will be made from billets, with appropriate heat treatments and WPC treatment (pretty much every moving component should WPC treated if it's highly stressed), internally balanced, harmonically dampened using something better than a rubber torsional vibration damper (because that has a +/-25Hz limit, so not usable over the entire rpm range), short crank throws, pistons that are properly cooled (steel would be better than any type of Aluminum for fatigue life, but cooling is the real challenge with steel), and lower volumetric power output levels associated with low levels of boost.

Forged Aluminum is typically denser than cast Aluminum, but it won't last as long as a casting in normal use because it will suffer from fatigue cracking faster than a casting as a result of thermal expansion that requires looser piston-skirt-to-cylinder-wall tolerances (and associated banging around in the cylinder bores during engine warmup).  However, forged Aluminum or forged steel can also survive power output levels that Aluminum castings wouldn't survive at all, even for a little while.  That's why forged 2618 alloy pistons are used so frequently found in both gasoline and diesel race engines.  The 4032 hypereutectic (high Silicon) alloys are a kind of compromise that undergo less thermal expansion as they heat up, but aren't quite as strong as 2618, so they have better service lives in higher power output engines that don't get too crazy with the hp per cubic inch figures.  Overall, the castings seem to be preferred for longevity.  All of the high continuous output aircraft engines, which are still only 1/2hp to 3/4hp per cubic inch, use sand castings, if that tells you anything.  When you warm up those fancy 2618 alloy pistons, they're going to slap the cylinder bores more than tighter tolerance castings, until the engine heats up to operating temperature.  If you get up to around 2hp per cubic inch or so, that's a moot point because the casting alloys wouldn't survive the torque reversals and operating loads anyway.  Aluminum is much easier to keep cool than steel at higher power output levels, which is a good thing, because Aluminum will weaken considerably by 300F and fail completely if it gets significantly above 650F or so, in a piston application.  The combination of charge air cooling and oil squirters remove enough waste heat, fast enough, to keep Aluminum pistons alive.  The forged racing pistons typically use a ceramic thermal barrier coating as well.

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#468 2020-12-05 17:03:38

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 26,798

Re: Housekeeping

Experience with the boxer engine in the subaru makes some of the design choices made questionable for how it's going to fail.

The heads from the engine have been removed and damage to where the head gasket failed is quite discernable to the touch as well as to the unaided eye on the heads and block.

With need to fine sand/remove it's imperfections before putting the new gasket a in. Will also need new stretch bolts for them as well. Of course that means torquing them and letting them set for 24hrs before giving a final torque. This may mean partial assembly for engine to be put back in before doing so.

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#469 2020-12-05 19:58:56

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,054

Re: Housekeeping

For SpaceNut re #468 ... thanks for the update on the Subaru motor head gasket failure!  I was glad to see that your hard work of diagnosis and disassembly paid off with an accurate problem identification.  I hope your solution is effective, and that the motor runs well and for a long time after.

I assume (and hope) the Subaru engineers have addressed the vulnerability you have seen in later models.  It may too much to ask, but since you have seen a failure up close, it would be useful if you could document what you observed and the remedy that future designers (on Earth or on Mars) might keep in mind.

For kbd512 re #468 ... that post deserves to be findable .... I'll take a shot at categorizing it.  You covered so much ground it may be difficult.

SearchTerm:Todo Make tags for kbd512 #468

(th)

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#470 2020-12-05 20:04:11

kbd512
Administrator
Registered: 2015-01-02
Posts: 6,240

Re: Housekeeping

SpaceNut,

Most factory-built engines are engineered for a specific production cost and weight.  The engine alone could cost as much as the chassis it's dropped into, or more, dependent upon the quality of the components used.  The engineers can make an engine design far more durable if you're willing to spend far more money, but so many consumers want something that will last the two to four years that they intend to use it, so that's what the automotive manufacturers deliver.

Would you spend $20K on an engine that lasts 20 years before major overhaul?

If not, then complaining that they built an engine for 1/4 of the cost, that still lasts 5 to 10 years, is a waste of time.

There are specific things that could be done to factory automotive engines to make them last longer:

1. CGI block / crankcase
2. Billet steel main caps, main cap girdle, crankshaft, camshaft, connecting rods, flywheel, and timing gears with WPC treatment
3. Engine fully studded with ARP studs
4. 4032 pistons with WPC treatment and ceramic thermal barrier coating
5. Hydraulic roller cams (pretty standard these days, but it does cost more)
6. Forged steel pedestal-mount rocker arms with pressure lubrication
7. Inconel exhaust valves and exhaust headers with thermal barrier ceramic coatings
8. Use of Aluminum limited to pistons, headers, water pump, and intake manifold (steel oil pan for durability)
9. Limited boost, if any, and a very sophisticated set of electronics for engine control (EFI and EI a must for durability)
10. Staying at or under 1hp per cubic inch of displacement

Edit: Some more longevity components to add (and it all costs more money):
Adjustable stainless steel clamps rather than bolts for exhaust fittings
Multi-layer stainless steel gaskets
Stamped stainless steel valve covers
Waterless coolant (will last the life of the engine)
Aluminum radiator
Aluminum hoses / pipes instead of rubber for coolant
Aluminum or stainless steel fan instead of plastic
Permanent magnet starter / alternator vs air cooled copper and iron (integrated into the flywheel housing)
Electrically driven AC compressor (for minimization of power losses to engine-driven accessories)
No power steering (for minimization of power losses to engine-driven accessories)

All that extra work for a modest power and displacement V8 will cost between $20K and $30K.  The turbocharged I4s are incapable of providing the horsepower of a V8 without service life limiting compromises and most I6s won't fit in modern engine bays and/or weigh every bit as much as a V8.  Basically, we're talking about building cost-is-not-an-object race engines with modest output.  It can be done, but most people don't see the point in paying for a race engine with pedestrian performance.  In short, we're reverting back to supremely well-built versions of the muscle car era engines of the 1960s and 1970s, with electronic controls for fuel economy, emissions reductions, and improved durability from consistent combustion.  There may not be much of an aftermarket for them since we've already used the absolute best components that money can buy.  If you're willing to pay for all of that, then you can have an engine that lasts for at least 20 years before disassembly of major components.

So... It can be done, but who will buy them?

Last edited by kbd512 (2020-12-05 20:23:01)

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#471 2020-12-05 20:04:39

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,054

Re: Housekeeping

For SpaceNut re Subaru repair ... I sure hope you are doing that work indoors?

Is the space heated?  That would sure make a difference! 

(th)

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#472 2020-12-05 20:17:16

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 26,798

Re: Housekeeping

The engine is inside for the repair work.

As for engines lasting ten years is about how long the body panels are lasting before they rust through under the plastic dress and yet they already cost you that twice amount to purchase.

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#473 2020-12-05 20:35:06

kbd512
Administrator
Registered: 2015-01-02
Posts: 6,240

Re: Housekeeping

SpaceNut,

The sheet steel bodywork can be replaced with fiberglass composite.

PowerNation - Build a Kit Car with ONLY a Drill, Pop Rivets, and Rattle Can Paint - Engine Power S2, E10

Tubular steel chassis, Aluminum sheet metal interior, fiberglass bodywork, rattle can paint on everything.

Two seater mini cars are another potential alternative:

Urban Hillbilly Videos - CRAZY Hand Built MINI NOVA !!!

Again, the hand-built Mini Chevy Nova uses a tubular steel chassis, fiberglass body work, and a motorcycle engine instead of a V8.  That said, if you want the engine to last, it's going to be about 4 times the price of a regular motorcycle or snow mobile engine.  However, the I4 Yamaha Apex snowmobile engine could be built to provide 300hp or so, if desired, and operate at 100hp or less the rest of the time.

Edit:

The stock Yamaha I4 short block weighs about 125 pounds, so one person can easily pick it up.  The 300hp Edge Performance version that Steve Henry uses in his STOL drag racing championship aircraft (you take off as vast as you can, fly a short distance, land, turn around, then race back to the starting line) makes about 300hp.  That entire setup, firewall forward, less engine propeller and cowling, weighs about 170 pounds.  There are even higher performance drag race versions of that Yamaha I4 that crank out 600hp, but they're not cheap and require extensive modification to every component in the engine.

Edit #2:

You can only use 300hp for takeoff, but then you have to immediately throttle back to avoid overheating the valve train and head.  The advantage is that Steve's takeoff distances are 25 feet or less, so the aircraft gets airborne in about the same length as the aircraft.  He's at full throttle for perhaps 20 seconds, climbs a short distance, levels off, and throttles back.  Believe it or not, his machine falls within the Light Sport Aircraft (LSA) category (1320 pound max weight, 138mph max speed, 45mph stall speed, 2 people, fix pitch prop, fixed landing gear).  It's the closest thing to a helicopter in a completely conventional bush aircraft that you'll ever see- it can takeoff and land in tiny spaces, turns quite well, rolls over large rocks easily thanks to the Airframes Alaska BushWheels and 18" travel shock absorbers.  These types of aircraft can fly at speeds between 90mph and 120mph, on average.  Some are a little faster, but most are not because they're optimized for very low stall speeds of 30mph or less.  They're tubular steel (same 4130 chrome-moly tubing as the cars listed above) with fabric or plastic coverings.  The wings are tubular Aluminum and wood or composite ribs, a design feature borrowed from ultra-lights.  Max comfortable operating ceiling is between 10,000 and 12,000 feet, although some of the Zenith STOL designs have been taken up to 20,000 feet or more using turbocharged Honda engines and oxygen cannulas for the pilot and passengers.

Last edited by kbd512 (2020-12-05 20:57:46)

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#474 2020-12-06 11:09:48

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 26,798

Re: Housekeeping

Power did drop for a second during the night but it came back up. We ended up with 8 inches of wet snow as it rained during part of the storm and was quite windy during the night.

Saw id's 463 - 477 were established and performed the unban function on those accounts.

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#475 2020-12-06 12:38:46

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,054

Re: Housekeeping

For SpaceNut re finished ID's ... thanks for catching those ... the Sunday Morning News interrupted the work session.

Will finish 478 - 484 shortly.

For SpaceNut ... when you get a chance, please look at this ID ... email / name mismatch and never posted

Username : AbbyManson

User activity
Registered: 2017-04-27
Last post: Never
Last visit: 2017-04-27 15:39:58
Posts: 0 - Show all topics - Show all posts - Show all subscriptions

For SpaceNut ... ID's through 484 are ready!

FYI ... new procedure with triple check ** should ** reduce error occurrence.

(th)

Last edited by tahanson43206 (2020-12-06 12:52:57)

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