New Mars Forums

Official discussion forum of The Mars Society and MarsNews.com

You are not logged in.

Announcement

Announcement: As a reader of NewMars forum, we have opportunities for you to assist with technical discussions in several initiatives underway. NewMars needs volunteers with appropriate education, skills, talent, motivation and generosity of spirit as a highly valued member. Write to newmarsmember * gmail.com to tell us about your ability's to help contribute to NewMars and become a registered member.

#176 2021-01-20 20:09:19

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,024

Re: Internal combustion engines for Mars

That would mean less compression and temperature shift is required from glow or spark plug ignition to occur.
So far we have quite the variety of engines and fuel combinations that are more than plausible for mars use..

Offline

#177 2021-01-24 11:24:32

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,024

Re: Internal combustion engines for Mars

Offline

#178 2021-02-08 12:01:24

kbd512
Administrator
Registered: 2015-01-02
Posts: 4,601

Re: Internal combustion engines for Mars

SpaceNut,

SCCO2 is a necessary technology for heat engines, the only type of 24/7/365 power plant in existence, for use here on Earth and on Mars, whether solar or nuclear.  Both photovoltaics and batteries degrade over 25 years (photovoltaics) or 5 years (Lithium-ion), we don't have good methods for recycling them, and we can never make enough with available raw materials to satisfy demand.  A glass encased mylar film or polished stainless steel reflector does not degrade appreciably within a human lifetime (we even have a few select examples of well-cared-for non-stainless steel from the Middle Ages in good physical condition).  A molten salt thermal power storage liquid and CO2 power transfer fluid do not degrade at all under the conditions we would use them, and both materials are abundant / easy to obtain / low-cost, both here and on Mars.  A high-grade steel SCCO2 turbine does not appreciably degrade over 25 years.

We have had diesels running continuously in oil fields for longer than photovoltaics have existed.  We have had solar thermal and nuclear thermal since the beginning of time.  Until such time as the new hotness in battery and solar technology are recyclable, the simple heat engine is the way forward.  We need to recycle the CO2 by pulling it out of the atmosphere.  The only energy equation that matters is whether or not we have more power output than power input.  We can get that from solar thermal or nuclear thermal, as well as liquid hydrocarbons by way of H2O and CO2 recycling.  Without those things, technologically advanced human civilization ends.  One day, many years from now, we may master photovoltaics and batteries, but we're nowhere close to that technology goal despite chasing it for the better part of half a century now without achieving the result we're after.  All power technologies have their uses and I'm onboard with developing all of them, but heat engines are the bedrock of modern human civilization.

Offline

#179 2021-02-08 14:49:57

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 7,208

Re: Internal combustion engines for Mars

For kbd512 re #178

I was with you right up to this line:

The only energy equation that matters is whether or not we have more power output than power input.

(th)

Offline

#180 2021-02-08 16:25:58

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 1,154

Re: Internal combustion engines for Mars

This belongs in the nuke mobile topic, but it occurred to me after reading kbd's post.  If we are going to use a nuclear reactor to melt phase change material, then it would make sense using that material as a gamma shield.

We would mount a sodium cooled fast reactor on a trailer along with its SCO2 power generation machinery.  The phase change tank would sit in the middle of the trailer.  The reactor would be at the back.  The SCO2 machinery and generator would be mounted forward of the phase change tank, partially shielding it from high gamma fluxes during reactor operation.  The reactor would be surrounded by a tank of water, which is just thick enough to reduce fast neutron fluxes during operation and thereby prevent activation of materials on the trailer.

At the end of each day, the rover would be detached from the trailer and would drive several hundred metres away from it on battery power.  The rover would be positioned so that the phase change tank obscures view of the reactor.  The nuclear reactor would then be run and the heat would melt the phase change material whilst the crew sleeps.  A few hours before sunrise, the reactor would shut down, allowing a few hours for short lived fission products to decay.  After a few hours of shut down, the rover reverses back and hooks the trailer back up.  The vehicle then drives on stored heat, which runs the SCO2 power generation loop.  The phase change tank would serve a useful secondary function of absorbing decay heat from the shutdown reactor.

This set up appears to allow a minimally shielded nuclear reactor to power a rover.  By relying upon distance instead shielding as the dose reduction measure, a nuclear reactor can be made quite compact.  There needs to be enough shielding to prevent dangerous gamma doses from fission products to people walking around the trailer during the day.  But this is a few inches of steel, around a core that is perhaps 30cm in diameter.  Such an arrangement could therefore be very compact.  It also has the advantage of providing a detachable powerplant, that can be removed from the rover at a destination and used to power equipment or provide process heat.  If we needed to work around a reactor during operation, a shield bunker could be dug out.

Last edited by Calliban (2021-02-08 17:20:20)


Interested in space science, engineering and technology.

Offline

#181 2021-02-08 18:32:30

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,024

Re: Internal combustion engines for Mars

CO2%20phase%20diagram.jpg

First problem is thermal concentration for this is a fixed point due to size of reflective surface required to raise the temperature pressure to make it stay sustainable for making use of its phase change due to heat. Salt takes even more heat to make it molten....

Offline

#182 2021-02-08 21:29:02

kbd512
Administrator
Registered: 2015-01-02
Posts: 4,601

Re: Internal combustion engines for Mars

tahanson43206 wrote:

For kbd512 re #178

I was with you right up to this line:

The only energy equation that matters is whether or not we have more power output than power input.

(th)

tahanson43206,

We can't perpetuate a technologically advanced human civilization without enormous energy input.  In this universe, using known physics and technology we actually have in hand, that is simply a fact.  All life requires energy to continue.  The more sophisticated the life form, the greater the energy input it will require.  Every bit of the whiz-bang technology we have today was the result of copious quantities of energy input.  To pretend that life as we know it will continue, absent enormous energy input, is fallacious thinking.  When it comes to the master resource, there's no such thing as "doing more with less".  You can improve efficiency, up to 100%, but beyond that, absent additional energy input, technological progress grinds to a halt.

Photovoltaics, for example, weren't created by subsistence farmers using ox-drawn plows to till the land.  We industrialized using coal / oil / gas / nuclear, labor became specialized because the resultant energy abundance permitted enormous amounts of time and energy to be sunk into children with improved education.  A veritable explosion of new technologies resulted from that energy investment.  One of them was photovoltaics.  In the many thousands of years of human existence under subsistence farming prior to that, not even the most rudimentary electronic devices were created.

New knowledge was most certainly piled upon extant knowledge, so that was likewise very important, but we went from walking and riding horses to landing on the moon, in a single human lifetime.  Two generations, possibly three dependent upon how you interpret the process of industrialization, from making steel / concrete / textiles / food in mass quantities, to sending rockets and spacecraft to other planets.  A dedicated and experienced rider could cross America in a month or two on horseback without killing their horse in the process.  A train or car can make the trip in a matter of days.  Jet aircraft can complete the trip in a matter of hours.  Spacecraft require less time than it takes to eat a meal.  The only constant there, as it relates to energy, is that the faster you want to complete that trip, the greater the energy input required.

Offline

#183 2021-02-08 21:57:23

kbd512
Administrator
Registered: 2015-01-02
Posts: 4,601

Re: Internal combustion engines for Mars

Calliban,

Using small, portable nuclear reactors in conjunction with combustion engines would enable us to consume power while stationary to produce liquid oxidizers and fuels to power vehicles during transits to / from work sites.  If you're going somewhere to dig a well, then when you're not otherwise using the power output of the reactor for life support / heat / drilling activities, then you can convert some of that reactor's power output into storable liquids for later use for transportation or emergency power.

If you have a 100kWe reactor, that's not enough power to propel a heavy duty (well-built and therefore reliable) off-road vehicle, but a 30cm core diameter (and perhaps a meter or two in length) is realistic for that level of power output.  However, if you run that reactor at moderate levels of output for a couple of weeks, in order to split a storage tank filled with CO2 into storage tanks filled with O2 and CO, then over that period of time you have sufficient power for both life support and creating the liquid fuels to supply the energy input necessary for a three vehicle convoy (one of them being a remotely piloted vehicle holding the reactor), to travel, say, 500km from where you're presently at.  When you get to where you're going, then you have a month or two of drilling activities or local exploration to identify natural resources for extraction, so there's adequate power available for recycling the CO2 to make the trip back to your main base of operations.

As far as efficiency is concerned, it's not efficient at all, but either a substantial percentage of a vehicle's total tonnage will be batteries, or you accept the inefficiency of using the reactor as a heat engine to produce liquid fuels as a necessary part of the resource identification and extraction mission.  The planning for that mission is not, in any way, subject to the effects of Martian dust storm / weather events.  The nuclear reactor doesn't care if it's pitch black outside or as bright as the surface of the Sun.  You come and go whenever you're ready to do so- and that's the principle benefit of 24/7/365 on-demand power output.  Strangely enough, after metal ships / trains / cars / aircraft were created, that's pretty much how mission planning has been done.  Aircraft obviously can't take off in a hurricane or tornado and ships can't set sail during a tsunami, but anything short of the most extreme weather events nature can throw at us, and it's business as usual, no matter the local weather conditions or time of day.  I would think that's how a truly technologically advanced society would approach mission planning, meaning we use utterly reliable technology to produce the end result we're after (making the trip whenever we're ready to do so, rather than having the Sun or Mars itself dictate when we can travel).

Offline

#184 2021-02-09 04:56:57

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 1,154

Re: Internal combustion engines for Mars

Below is a link to the 2015 Quadrennial energy review, produced by the US department of energy. https://www.energy.gov/quadrennial-tech … eview-2015

Go to Section 10, Table 10.4 for a summary of materials inputs into several different types of powerplant in ton/TWh. Here are some tallys per TWh:
Nuclear (PWR) = 760t concrete / cement; 3t copper; 0t glass; 160t steel; 0t aluminium.
Wind = 8000t concrete / cement; 23t copper; 92t glass; 1800t steel; 35t aluminium.
Solar PV = 4050t concrete / cement; 850t copper; 2700t glass; 7900t steel; 680t aluminium.

1. Compared to a pressurised water reactor nuclear power plant, a solar PV plant producing the same electric power output will require some 5.3x more concrete; some 280x more copper, some 49.4x more steel; and thousands of times more glass and aluminium.

2. Wind turbines (presumably onshore) require about an order of magnitude more materials for the same amount of electrical energy generated.

The reasons behind this are simple.  To intercept enough solar energy to produce 1GW average of power, you need to cover about 200 square kilometres of land with solar panels or about 500 square kilometres with wind turbines at maximum density that wind shadowing will permit.

There is no indication that these quantities include any materials investments needed for energy storage. This would require further materials investments in pumped hydro, CAES or some other means. This increases the materials cost of wind and solar still further. Embodied materials are a reflection of embodied energy.

The heavy materials budgets of wind and solar on Earth, are a consequence of the low power density of wind and solar energy.  This is the nature of the resource and not something that technology can change.  It tends to make the energy cost of energy quite high for renewable energy sources.  On a societal level, that will tend to make people poorer as we switch over to sourcing more energy from these resources.  The reason is quite simple.  A lot more of the energy that we would have used to produce other goods and services, will need to be reinvested in the power producing equipment that we need to power society.

It also means less energy available to grow the economy (which means forgoing consumption and investing in the future) and what we do invest will produce less growth, as economic infrastructure is becoming more energy and materials intensive.  When we take into consideration the fact that energy infrastructure is only one part of the total infrastructure that needs to be maintained for society to function, there can be no doubt that switching to lower EROI energy sources will make society poorer and we will inevitably experience degrowth.  This is now inevitable at a global level.  On average, the next generation of human beings will be poorer than their parents.  One can see the bell tolling by looking at the stagnation in the growth of global exports since 2008.  Most of the apparent increase in GDP in Western countries since 2008 is an illusion resulting from the spending of borrowed money.  This has inflated stock and asset prices, but the real goods economy has been stagnant.
https://data.worldbank.org/indicator/BX.GSR.MRCH.CD

On Mars, the solar constant is only 43% of Earth's and there is too little atmosphere to support wind power.  If Martians are to build a technological civilisation on Mars, it is clear that we need a richer energy source.  Nuclear fission is the only energy source that fits the bill in current technology sets.

Last edited by Calliban (2021-02-09 05:25:12)


Interested in space science, engineering and technology.

Offline

#185 2021-02-09 17:48:46

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,024

Re: Internal combustion engines for Mars

Which brings me to size matters in why KRUSTY make sense  for mars use not to much mass, steady 10kw electrical, plus a plausible 30kw of IR heat make use of and its already a molten salt unit.
Use an up draft chimney to heat compress Mar's Co2 and create power from the updraft.

Here is my post of the use of the pair in a solar chimney design

Offline

#186 2021-02-11 12:44:32

kbd512
Administrator
Registered: 2015-01-02
Posts: 4,601

Re: Internal combustion engines for Mars

SpaceNut,

This is really "nuke mobile" content, but in response...

We could design a "bespoke" KiloPower reactor that only generates thermal power output to split CO2 into CO and O2, or to heat a tank of molten salt.  The 10kWe KiloPower reactor is actually generating 40kWt, all of which can be used to supply process heat.  At the temperatures involved, a molten salt could store roughly twice as much power per unit mass as a Lithium-ion battery.  If the crewed vehicles in a convoy were using tanks of molten salt to provide thermal input power to 50% efficient SCCO2 gas turbine, then you have a 100% reusable solution that doesn't require re-generation of chemicals, has roughly the same gravimetric energy density as Lithium-ion, but without the battery degradation problems.  The "battery" still weighs 8t, but it will last until the ceramic containment unit cracks.

If the process heat is used to re-heat the molten salt, then it would take a bit over 100 hours, or 4 days, to recharge a single battery.  The insulated tanks lose less than 1% of the stored heat per day, so it's practical to recharge several vehicles with a single reactor, over a few weeks.  If a single tracked vehicle carried 4 reactor cores, then all of the vehicles in the convoy can be recharged in less than a week.  A foot of steel surrounding each coffee can should be sufficient to shield the reactors.  Maybe a stainless steel foam impregnated with Boron can shield against both neutrons and gamma for less weight.  It'll be really heavy, but it should work.

Offline

#187 2021-04-14 19:12:32

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,024

Re: Internal combustion engines for Mars

If we tap into a methane source for mars or what a denser fuel we might want to convert it to gasoline…
Turning greenhouse gas into gasoline; New catalyst provides design principles for producing fuels from carbon dioxide emissions.

Offline

#188 2021-04-14 20:05:55

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 7,208

Re: Internal combustion engines for Mars

For SpaceNut re #187

Thank you for the link to the research on production of CO from CO2.  One detail that the author did not explain was how H2 is produced from CO2 ... I suspect there is something omitted from the article ...

In any case, I was happy to see support from the USAF and participation by MIT...

The research was supported by the Air Force Office of Scientific Research and the MIT Department of Chemistry, and is part of the research taking place through the MIT Energy Initiative’s Low-Carbon Energy Centers, established as part of the Institute’s Plan for Action on Climate Change.

On Mars, there may be a reason to try to create chemicals that incorporate Hydrogen, but with the effectiveness of CO as a fuel, I just don't see the point.  You'd be investing more energy in making the products that include Hydrogen, but you would still need to carry enough Oxygen to oxidize whatever material you have, so why bother?

If there is someone with a chemical background who would be willing to take a look at the situation, I'd be most interested to see a comparison.  My guess is that CO would turn out to be the most cost effective solution on Mars, because of compounding losses in manufacture of materials that include Hydrogen.

(th)

Offline

#189 2021-04-18 11:21:37

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,024

Re: Internal combustion engines for Mars

repost

Calliban wrote:
louis wrote:

I'd forgotten about this. It does seem that my original thought, that you could capture CO and oxygen from the atmosphere   and have a ready made energy store when humans landed a couple of years later is not so crazy and could work. Whether it's worth going to that trouble compared with just loading 30 tons of methane and oxygen on a Starship is another matter. I guess boil off over two months might be an issue?

If I read this correctly, Louis is suggesting the capture of CO and O2 already in the atmosphere on Mars.

It could be done, but it is no trivial undertaking.  The Martian atmosphere is 95% CO2, 2% Argon, 2.8% Nitrogen, 0.174% O2 and 0.0747% CO.  For this to work, you must first separate the CO2 from the other gases.  The CO2 in the Martian atmosphere is close to its triple point temperature, so relatively little compressor work would be needed to increase its density relative to the other components.  The remaining gases would be 40% Argon, 56% N2, 3.48% O2 and 1.49% CO, by volume.  The CO would be about 1% by mass.  On this basis, the calorific value of the non-CO2 content of the Martian atmosphere is about 100KJ/kg ( CO heat of combustion is 10MJ/kg).  At 1bar, the mixture would have volumetric energy density of 150KJ/m3.  At 300bar, it would be 45MJ/m3.  Because the CO and O2 are present in low concentration, you could probably store the mixture in a single tank, without risk of explosion.  To burn it, you would may need to pass it through a heated catalyst bed, as the concentration of fuel and oxidiser is too low to support flaming combustion, even under extreme compression.

In terms of total work output, one needs to compress 19kg of CO2 for every 1kg of stored gas mixture, which would release 100KJ of energy when released.  Put another way, the chemical energy content of the Martian atmosphere is 5KJ/kg or 65J per cubic metre at 6.1mbar.  This is almost certainly too little for any release of net energy from compressing and combustion of the Martian atmosphere.  None the less, it may be interesting to consider this as an energy storage mechanism.  The compressed CO2 has its own value as a CAES working fluid.  Heating it above 31°C would produce high pressure gas that could drive a compact gas turbine.  The stored compressed residual CO containing mixture has chemical energy density 100KJ/kg.  Taking the Cv of the gas to be 1KJ/Kg.K, complete combustion would raise the temperature of the gas by 100°C.  So along with its internal pressure energy, it could be a useful energy storage mechanism for short range vehicles and compressed air tools.  It is worthy of further investigation, I think.

Offline

#190 2021-05-17 19:24:15

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,024

Re: Internal combustion engines for Mars

Took a refreshing 50 minute 2 mile walk to the garage to pickup the rebuilt 2008 subaru outback. The engine still needs so more run time to set the vehicles computer to ready for the state inspection but it passes the safety inspection for a 60 day sticker. This give me time to break the engine back in slowly checking fluids after and before each use gradual run of distance and timed use. It has had several idling in the garage lot after rebuild of 2 - 3 hours and it did not over heat but needed fluids as these are notorious for trapped air when refilling them.

Offline

#191 2021-07-18 20:12:09

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,024

Re: Internal combustion engines for Mars

found a video of my Subaru's outback engine compartment
Subaru Impreza Engine knock

Granted they are looking for a knocking sound and the process to determine what it might be...

The head I suspect has cracks that are not visible and the engine has started to knock so it looks like
If its just a leaking head gasket this is what would be done

In the vehicle gasket replacement

I am in search of a replacement engine for the vehicle at this point

engine removal

engine rebuild once out of the vehicle

some of the teardown process that I have done.

Offline

#192 2021-07-18 21:23:31

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 7,208

Re: Internal combustion engines for Mars

For SpaceNut re #191

Thanks for the several videos ... I followed the engine rebuild one most of the way through ... I liked the way they changed the pace to shorten the video while showing all the steps.

Sorry to hear that after all the work you put in, the engine is not going to be good for the long haul.

Best wishes for success finding a replacement engine ... How would you know what condition such an engine might be in?

Is there a way to test it on a bench before you commit to purchase?

***
Since this ** is ** the topic for IC on Mars, I wonder how many of the same issues will be present there?

We've discussed using CO and O2 as the fuel and oxidizer, so you'd be feeding different inputs into the machinery, but the need for high quality oil would be exactly the same.  The earlier discussion didn't get into details of temperatures and combustion chamber pressures, so those details remain to be added to the topic. 

Question of you ... since Subaru improved the engine in subsequent years, is there a chance one of the later ones would fit the cavity?

I recognize it is unlikely, but it is probably worth asking.

(th)

Offline

#193 2021-07-19 00:52:38

kbd512
Administrator
Registered: 2015-01-02
Posts: 4,601

Re: Internal combustion engines for Mars

SpaceNut,

Maybe it's time to consider a rebuilt or low mileage GM Ecotec or Honda Inline 4.  Some research will be required to determine what will fit within the dimensions of your engine bay without cutting anything, though I'd be willing to bet that there's more than one engine that will fit.  If this is a Subaru EJ20 or EJ25, then you're golden on engine width and length, although height may be a bit of a problem, or maybe not, dependent upon how much crap is mounted atop that engine in the engine bay.  It has the same rev range, a little more power, and it's a bit lighter to boot.

GM LTG Crate Engine Dimensions

If this is a Subaru Forrester or Impreza or something like that, then a number of people have swapped in 5.3L GM LS series V8 engines into such vehicles.  What's wrong with getting a plain Jane naturally aspirated American V8 and calling it a day?  Rich Rebuilds swapped a LS into their dead Tesla, which magically transformed the vehicle into a working Tesla.  You can pluck LS motors from wrecking yards across the country without spending a small fortune.  At the end of the day, you'll have a reliable engine that doesn't require scarce and expensive parts.  Perhaps most importantly, the engine makes V8 sounds, rather than silence.

Whatever you choose, I hope it serves you well.

Offline

#194 2021-07-19 01:43:57

kbd512
Administrator
Registered: 2015-01-02
Posts: 4,601

Re: Internal combustion engines for Mars

tahanson43206,

Generally speaking, a mechanic "knows" the condition of a junkyard replacement engine by first taking it apart, sometimes at the junkyard but usually after taking the engine back to their shop, by which time it's generally too late to bring it back if it doesn't work, visually inspecting all of the components, and repairing or replacing anything that's excessively worn or damaged.  If you had a working vehicle equipped with a mobile engine dyno to bring to the wrecking yard, then you could absolutely pull and test a motor prior to purchasing it.  So yeah, without that million dollar mobile test rig that all shade tree mechanics seem to lack, it's mostly a crap shoot, just like life.  Hey...  Maybe that's a metaphor for life.  Most of the time it pays off, but sometimes it doesn't.  If you never try, then it won't "pay off" 100% of the time, guaranteed.  How's that for a life metaphor?

Out of curiosity, how do you normally know what the condition of an engine is?

I only ask because I've never personally done or even seen it done any other way, but I was hoping that maybe you read about some newly developed X-ray vision whiz-bang computer technology out there that can tell me the condition of the crankshaft and rods and bearings without ever turning a wrench or eyeballing the part in question.

I thought of another metaphor for life:

Riding in a "mowtah caah", whether it's a Rolls-Royce or not, beats walking 25 miles through the snow to work, every day of the week- unless your name is Forrest Gump.

I also learned the following from Smitty Ray during my time in the Navy:

"Nevah paak the caah at Hahvaad Yaad."

Given the option, though, I would rather ride in a Rolls, so long as it doesn't have a European engine in it, because they still haven't figured out that how well an engine functions means everything and how needlessly complex it is means nothing at all, except how often it'll break and irritate its owner.  Someone at BMW hasn't informed their engineering staff that changing a spark plug shouldn't involve removing the engine from the engine bay.  Ferrari or Lamborghini?  Fuhgeddaboudit!  Sometimes I feel as though the engineers who work for BMW could've taught Rube Goldberg a lesson or two.

If we could send our factory workers over to Rolls-Royce to teach them about craftsmanship and attention to detail, and they could send their powertain engineers over here to learn about how an engine should be designed and built, then "with our powers combined" smile, I feel like we could have both vehicles and engines that could be passed from generation to generation, possibly saving enough energy that we wouldn't need to concern ourselves with running out of dino juice for at least another century, by which time we will hopefully have perfected teleportation, replicators, and ride around on electric unicorns that only emit rainbows from their tailpipe as they prance about.

Offline

#195 2021-07-19 04:53:27

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 7,208

Re: Internal combustion engines for Mars

For kbd512 re #194

SearchTerm:unicorns rainbows
SearchTerm:rainbows unicorns

SpaceNut seems to have a practical problem to solve.  As nearly as I can tell from his reports, he has a policy of only working with cash, so borrowing funds to invest in a new vehicle is not an option.  He bravely opted for a Subaru with a few years and a few miles on it, and found that the engine overheated.  Apparently that particular model year has a history of overheating.  In any case, SpaceNut bravely dove into a repair project that only a few people I've ever met would tackle.  I've certainly met such people, and had an Uncle who ran a repair shop, but in my experience, they are only a handful of (probably) thousands of people I've met over the years.

After all that work, it sounds (as nearly as I can tell) as though the engine is failing again. 

Thanks for your review of the options for evaluating an engine.  Perhaps the practical (for the average person) best practice is to drive a vehicle before buying it.   However, the problems that SpaceNut reported did not show up during the testing which (I presume) he must have done before committing to the purchase.

I doubt that anyone in the forum would venture to try to advise SpaceNut at this point.  What we ** can ** do is to try to follow his reports closely, and applaud when he reports success. 

(th)

Offline

#196 2021-07-19 17:48:36

kbd512
Administrator
Registered: 2015-01-02
Posts: 4,601

Re: Internal combustion engines for Mars

tahanson43206,

I'm glad to see we finally have my "rainbows and unicorns" catch-phrase bookmarked for posterity's sake.  When life's running you down, it's important to have a sense of humor about it.  It's a matter of perspective.

I never asserted that SpaceNut was obligated to do anything I suggested.  I did state that if Brand X's engines were giving him too many headaches, then maybe Brand Y's engines were worth a look.  Then again, I'm the type of person who would put a Ford engine in a Chevy just to watch people lose their minds over something that doesn't actually matter in the slightest.

Offline

#197 2021-07-19 18:51:02

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 7,208

Re: Internal combustion engines for Mars

For kbd512 re 196 ... glad to be of service << grin >>

Your output has included a number of posts worth remembering and finding again.  This forum software does not lend itself well to storing information for future retrieval.  I am hoping RobertDyck can overcome whatever hurdles he is facing to provide a (small) storage space for worthy items. 

An example is the post you created about how to prepare for an emergency, such as a hurricane,  It was (probably) written from the wellspring of your experience over many years, but I remember it as comprehensive, easily comparable to articles that occasionally appear in the paid press.

***
Regarding SpaceNut .... We are all respectful of each other's circumstances.  I do not envy someone who drives a Cadillac ... such a person has the means to maintain such a vehicle, and deserves to enjoy it.  That goes for almost anything you can name.  It seems to me that most of us try to do the best we can with what we have available, and enjoy (as best we can) whatever comes from the effort.

I ** am ** interested in the learning experiences SpaceNut has given himself, and which he shares with us as he goes along.  He has shown far more mechanical aptitude than ** I ** (for sure) would venture, although modest maintenance of household items is within my reach.

It is indeed disappointing if there is a defect in the Subaru engine that SpaceNut missed while he had it on the bench. 

(th)

Offline

#198 2021-07-19 23:28:18

kbd512
Administrator
Registered: 2015-01-02
Posts: 4,601

Re: Internal combustion engines for Mars

SpaceNut,

Are you looking for a replacement EZ30 motor for a 2008 Subaru Outback?

tahanson43206,

No disrespect towards SpaceNut was intended or even thought of.  I was only suggesting that he might be able to pluck a very nice domestic or Japanese engine from a wrecking yard for very little money (less than $1K for everything), since it may end up costing the wrecking yard more money if they ultimately have to scrap it.

Offline

#199 2021-07-20 07:34:38

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 7,208

Re: Internal combustion engines for Mars

For SpaceNut ... please keep us informed as you work through the present challenges. 

For kbd512 ... how might a person (member or forum reader) try to find an EZ30 motor (or equivalent direct replacement) for a 2008 Subaru Outback?

In the age of Amazon, it is possible there is an online resource where specialized equipment is put on offer.

eBay is more tuned to the used equipment market, although eBay ** does ** seem to carry mostly new items.

The market for used equipment seems dominated (at least from my perspective) by Craig's List. 

Later, when I'm on a modern computer, (and if I remember) I'll ask Craig's list about the EZ30.  I'd be surprised to find a listing.

Come to think of it, Google may be able to handle the information search for such a specialized item.

But ... how would **any** buyer know the item is serviceable.

It seems to me that trial-and-error (and blind luck) is the only visible pathway for anyone in the present situation.

Edit later: There ** is ** another option.  Having already demonstrated the ability to tear down an EZ30, SpaceNut might be able to tear it down again and look for the cause of a knock condition.  The video he showed via link recently was about burning oil, and the presenter showed damaged pistons. Solving a knock might require a comparable level of disassembly and inspection.

On Mars, there won't be any shade-tree mechanics, but there will be a ** lot ** of work-in-the-cave mechanics.

While use of CO/O2 for IC engines has been demonstrated on Earth, I expect it will become the main IC technology on Mars, due to the obvious benefits of eliminating hydrogen from the loop.  For that reason, I expect operation conditions of CO/O2 engines will receive attention on Earth before equipment is prepared for the Mars market.

Manufacture of synthetic oil has been discussed in this forum, and there are several posts (that I vaguely remember) that go into detail about it.

I frequently call for permanent storage for NewMars members, and this is another example of how such storage would be useful.

The existing structure could actually work if members learned how to use it efficiently for permanent searchable storage.

I've been using Post #82 of RobertDyck's Holiday's topic as a base of operations for the daily calendar report for several Earth years, and FluxBB finds it quickly and efficiently every morning.  The same technique could serve for almost any other topic with lasting value.

(th)

Offline

#200 2021-07-20 12:04:15

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 4,563
Website

Re: Internal combustion engines for Mars

In the old days,  a knock sound was usually just bad rod bearings.  Bad mains were a much deeper thump sound.  Not much else made sounds like that.  But with the modern equipment,  with all the computer-controlled variable valve timing and all that other stuff,  there are many things that can make a knock sound.  Even a bad water pump can sometimes make a knock sound.  It's all lightweight BS quality,  and many things wear out quickly and make racket.  A fair fraction of the replacement parts are bad right from the factory,  especially,  but not limited to,  the electrical/electronic stuff. 

You can make your own synthetic blend with standard oil plus a modest percentage of Lucas Oil Stabilizer.  Standard motor oil is about 80% refined petroleum (which does not wear out),  and about 20% the additive package which is a mix of liquid plastic polymers.  **** EDIT UPDATE 7-21-21 NEXT PARAGR****.  A full synthetic is 100% a mix of liquid plastic polymers.  Synthetic blends lie in between those extremes,  being part petroleum and part liquid polymers.  The plastic polymers also act to adjust the viscosity vs temperature curve;  multi-grades appeared when that technology first appeared,  before it,  there were only single-grade oil viscosities available.

EDIT UPDATE 7-21-21:  It is the additive package in a standard oil or a synthetic blend that wears out,  not the petroleum (in a full synthetic,  there is no petroleum,  it is all liquid polymers).  That,  and loading up with dirt and oxidation products,  is the way all these different motor oils "wear out".  When the additive package wears out,  your viscosity may be affected a little bit,  but your greasy sliding lubricity is completely shot!  THAT is the real problem,  and it is why you must change your oil and filter regularly:  every cold start is enormous wear! 

You can feel this if you put oil from the dipstick on the tips of your thumb and forefinger.  If the additive package is OK,  you cannot feel the slip-and-grab of your fingerprint ridges rubbing past each other.  If you can feel them,  your oil is past its proper change interval:  the additive package has failed.  You "calibrate" this by sliding thumb and forefinger tips dry:  it is quite easy to feel the slip-and-grab of the fingerprint ridges.  Then check the oil for greasy sliding lubricity.  You should feel no slip-and-grab,  no matter how hard you press together,  if the oil is still good.   END EDIT UPDATE 7-21-21

Oversimplifying,  the petroleum part is the bulk of the viscosity,  important to film lubrication (an analog to water skiing) inside the bearings.  The plastic polymers provide the bulk of the non-film greasy-sliding lubrication for valve train,  gears,  chains,  and piston rings.  If you enhance the greasy-sliding lubrication with more plastic polymers,  you greatly decrease the cold start wear before the film can form to float the bearings.  That's roughly 90% of your engine wear eliminated if you do that.  The next weakest link in the chain limiting engine life is then usually wear on the timing chain tensioners,  if so equipped (and most are). 

You get the extra plastic polymers either by buying synthetic blend (or a full synthetic),  or else by adding 10-20% Lucas Oil Stabilizer.  I've done the Lucas thing for about 4 decades,  so I know it works. 

GW

Last edited by GW Johnson (2021-07-21 12:14:51)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

Offline

Board footer

Powered by FluxBB