• Member Since 2nd Nov, 2012
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Admiral Biscuit


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  • Tuesday
    March Music Monday 4

    March Music Monday 4

    For all the :yay: . . . guff I pile on my manager, he occasionally dispenses pearls of wisdom, or names songs that it turns out that I really, really like.


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    26 comments · 171 views
  • 1 week
    March Music Monday 3

    I think I mentioned in the first one of these that my manager always plays the same top-40 Country station all day every day.


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    14 comments · 210 views
  • 2 weeks
    March Music Monday 2

    Alrighty fellow music lovers, it's another Monday in March, and you know what that means!

    ... 'cause you read the title :heart:


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    This one doesn't have as much of a back story.

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    9 comments · 212 views
  • 3 weeks
    March Music Monday 1

    This is pretty much what it says on the tin.

    See, ponies like music, I think that's pretty well-established canon. I like music, too, and I thought I'd introduce you to some music you might not have heard before. After all, I've been introduced to music by other people through the years, oftentimes something I'd never have found on my own.

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    29 comments · 295 views
  • 5 weeks
    MECHANIC: The Most Boring One Yet

    I hesitate to even suggest you grab your favorite beverage, you're just gonna skim this one. But, if you're game:


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    17 comments · 318 views
Dec
15th
2022

MECHANIC: Mazda Miata and Ford F150 · 3:02am Dec 15th, 2022

Alrighty, kids, it's time for another mechanic blog! This time we're gonna talk about a Mazda Miata I worked on nearly 20 years ago, and then a F150 that I worked on just recently.

But first, you know what to do:

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Many years ago when I worked at Firestone, a Mazda Miata came in for routine maintenance. Specifically, it came in for a timing belt.

In case you don't know what that is, the valves on an engine are controlled (usually) by one or more camshafts, which are linked to the crankshaft by a chain or a belt, or in some cases, gears. Each design has its own advantages and disadvantages. While chains and gears should be lifetime items—they should last as long as the car does—a timing belt isn't. Typically, it's recommended that they be replaced every 100,000 miles or so (160,000 km). The service interval varies by manufacturer.

Chains do stretch and wear, especially on modern overhead cam engines, but while a belt breaking is often a catastrophic failure or at the very least one which renders the car inoperable until it's fixed, a timing chain can jump a tooth or two and the engine will still run, just not as well.

The car was due by mileage, and good for the customer for being proactive and not waiting until it broke to get it serviced. In fact, he was so proactive, he called Firestone's customer hotline (which we called 1-800-Get-It-Free) to ensure that the job was completed on time, per the written estimate he'd gotten (about four hours for the job) and that he didn't get any parts upsells.

I'm not gonna say that there aren't shops that'll upsell unnecessary stuff, because of course there are. But I'm also going to say that things sometimes go wrong when working on cars, and a good mechanic knows when he opens stuff up he might find things that he couldn't see from outside. For example, right now I'm working on a Cobalt that needed a heater hose 'cause it was leaking . . . except when I got it off, I found the pinhole in the pipe that the heater hose attaches to, which is where it was actually leaking. All the pipe I could see looked good, so I wasn't expecting to find rust. Could I put a heater hose on, clamp it really good (maybe toss in some RTV as well) and send it out not leaking? Probably. Would that repair last? Almost certainly not. So we told the customer what we found, and now he's getting that coolant pipe, too.

Anyway, point is when I take off that timing cover, even if everything goes well, I might find that one of the pulleys (which weren't quoted on the estimate) has bad bearings, or that a gasket that should be reusable isn't, or any number of other things.


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Incidentally, I was informed of all this before I went into the job, so I didn't waste any time worrying about anything else I found that was broken, worn, or should be replaced as a precaution, I just noted it on the work order so my rump would be covered if things went south.

Since I'm talking about it in a blog post, you can guess that things went south.


I don't like doing timing belts; those jobs always seem to go badly for me. Whether it's trying to do one one-handed after I injured my shoulder, or discovering that Chrysler's 2.5L four-banger in the Dakota had two sets of timing marks (the ones you use and the ones you don't). Doing them on a PT Cruiser where you have no clearance at all, or a Ford Ranger that's so tired that everything crumbles into rusty powder when it's touched . . .

As timing belt jobs go, the Miata isn't bad. It's a simple routing, it's simple to get to, and it's a fore-and-aft engine, so leaning over the bumper you're looking right at it. The car was clean; it was a convertible and only driven in the summer. The instructions for the job were clear and concise, timing marks easy to see, and I got the belt on in the allotted time, rotated the engine over by hand to make sure that the marks lined up again, which they did.

Satisfied with my work, I put the car back together and turned the key, and it did not run.

I won't bore you with the variety of attempts to fix it that failed. There were a bunch, and I was losing money with every moment that car stayed in the shop, since I wasn't getting paid to do post-repair diagnosis. I determined that it had no compression, and it was towed to Mazda for them to figure out.


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What had happened was that the woodruff key in the crankshaft was broken. As long as the harmonic balancer stayed on the engine, it clamped the crankshaft gear in place, and the engine would stay in time. When it was removed, the crank gear could turn on the crankshaft; I put the bolt back in by hand (as you do) and turned the engine over to line up the timing marks, but since it wasn't firmly held, it rotated on the crank. Or maybe that had happened prior to me even getting the front cover off; there might have been some tension on the valves and they'd rotate the cam(s) to a neutral position, especially if the crank gear could turn freely on the crankshaft. Since I never slid the gear off, I never knew.

If I had known to look for it, I might have been able to save the engine; I might have been able to get it to TDC before removing the harmonic balancer, marked the old belt to match the timing marks, pulled the crank gear, put a new woodruff key in, lined everything up like it should be, and then it would have been okay.

The customer decided to not fix the car; he bought a little yellow Toyota or Honda convertible (can't remember the model) and he promised me that I'd get to do all the work on that car.

The next time I saw it was when I was unloading my new toolbox from the Matco truck, and I considered pushing my new box on top of his car, but I didn't.


My toolbox, loaded in the back of my truck some years ago


Which brings us almost to the present. About a month ago I put timing chains on a relatively low-mileage F150 with a 3.5L twin-turbo Ecoboost V6. I didn't diagnose it, but I do know about timing chain problems on those, especially if they weren't well-maintained. My manager wanted to do the full job, so we were doing the chain and the guides and the camshaft phasers and the oil control solenoids. And, since we're not Firestone and have mostly good, well-educated customers who trust us, if we found something else while we were working on it, we'd fix that, too. Or at least advise the customer [there have been a few 'I warned you that was going to break' situations over the years].

The job went relatively smoothly; I was fresh off the Econoline I blogged about a little while back, and I've done these before. We have the camshaft holding tools you need to do the job right.

The only thing that was unpleasant about the job was putting the front cover back on. A lot of times, there's a specified bolt tightening order, and there'll be an illustration showing the pattern in which you tighten bolts 1-n.


Also there are steps . . .

I tighten the bolts that are hand-written in like this:
Step one: tighten in sequence to 89 inch pounds
Step two: tighten in sequence to 177 inch pounds plus 45 degrees, except bolt 21.
Step three: tighten bolt 21 to 177 inch pounds plus 90 degrees.

Then I tighten the bolts that are printed the same way, except that bolt 22 is 89 inch pounds plus 45 degrees.


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Got it all back together, ran pretty good and even better when I connected the ignition coil I forgot to plug in when I put it back together. I was happy, the manager was happy, the customer was happy, and that happiness lasted for about a month.

It still runs well, but there's this little ticking noise from the engine, and the customer is being proactive and wants to know what's going on.

The ticking sounds like it's coming from around the right valve cover. Also, I can monitor where the cams are compared to where they're supposed to be, since it's a variable cam timing engine. One pair (I think it was the intake cams) are always five degrees off, while the other pair varies from six to ten degrees off.

Oil pressure is also lower than it should be. Hot idle is supposed to be 25psi; this one's at eighteen.

We covered oiling problems in the upper end when I talked about the Jeep (link!). I don't have a way to hook an oil pressure gauge up top on this one, but it's safe to assume that the 18psi at the oil filter means that there's less at the cams and phasers.

Pulling the right valve cover reveals nothing. Five degrees off isn't enough to be one tooth off on the timing chain (besides, if it had been, it would have set a code already and it hasn't). Some of you are probably already guessing where this is going to go.


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Hold that thought.


Some high-consequence parts are held in by torque-to-yield bolts. Those are designed to stretch a specific amount when they're installed to get maximum clamping load, and one of the hallmarks of them is a torque spec that's x foot-pounds (or inch pounds) plus y degrees. I don't know the exact technology or the full science behind them, but I do know that you shouldn't re-use them.

The catch for a shop is bolts get expensive, and while for some jobs you don't want to skimp (for example, a cylinder head), it's hard to justify spending an extra hundred dollars on front cover bolts, especially since it's held on with RTV, too, so if one of the 24 or so bolts isn't clamping as well as it should, all the others will make up for it.

On this engine, the one we really shouldn't have skimped on was the harmonic balancer bolt. It's also torque-to-yield with installation instructions similar to this:
1: install bolt finger-tight.
2: tighten bolt to 89 foot pounds.
3: loosen bolt 180 degrees.
4: tighten bolt to 36 foot pounds.
5: tighten bolt 90 degrees.

When I removed the A/C stretch belt (someday I'll tell you about that fun new innovation), the used harmonic balancer bolt I'd installed rotated one full turn, and when I got to the point of removing it from the crank, it didn't feel right. Kinda gritty and loose in the threads. If it's not holding the crank gear as well as it should . . . .

And when I put the bolt back in to rotate the crankshaft and line up the timing marks to make sure it was still in time and not a tooth off, I also watched the cam gear's relationship to the crankshaft, and this is what I saw:

(backup link)

This is not good, and what saved this engine was the customer's worry about the noise, and us tearing it down before the pin broke all the way.


The pin wasn't meant to hold the cam gear in place when the engine ran, just to line things up for replacing the timing chain. As the worn-out stretch bolt worked itself loose over the course of a month, the pin started to work way more than it ever should have. I assume the noise the customer was hearing was the cam gear slamming back and forth on that pin and the rotational speed of the crank changed. The more it wore, the worse it got, and I would guess that it would have only lasted a couple more weeks before the engine experienced dynamic disassembly.


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So yeah. I hate doing a job twice, especially when it's for a dumb reason, but at least we aren't putting an engine in it at our expense.


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Outro!


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Comments ( 31 )

Was feeling lazy and forgot to put the links to the Jeep upper end oil problem in.
Here's the problem

Here's the resolution

One thing that identifix advises for oil pressure problems on the Ford 3.5 VCT engine is to just replace the engine. We got bit by one a while back that had debris in the oil passages; we did the chains and everything else, but the screens in the new oil screens got plugged pretty quick when more debris shifted; that one wound up getting an engine at our expense a few months later.

Some learning occurred quick from this one; while I was working on it I also diagnosed an Equinox that was a no-start. Sounded like it had no compression, if not well-maintained, they're known for the timing chain eating its guides and then jumping teeth. The oil was low, the oil change was thousands of miles overdue, and there was glitter in the oil . . . rather than offer the option of putting chains on it and see what happens, I quoted an engine replacement or tow it away.

I mighta gotten fast and loose with torque-to-yield and stretch bolts, they're the same thing.

Also, notes on a blog post, what madness is this?

5703382
Funny, my ex used to say the same thing.

We covered oiling problems in the upper end when I talked about the Jeep (link!).

how ever will I find that blog now!? Why it's not like I can just go to your blog posts and find it.

when i was younger way younger i had a 1976 Chevy LUY truck with a tiny Opel 1.8 . i put a timing chain in that one summer after the old one broke. yep that was a full rebuild.
all back together and running really good. driving home from school i saw the oil pressure go from 85 hot to about 15 now i was going 55 at the time. lol i was 17 so yes i was going 55.
i found that one of the anchor pins holding the timing slide rail had blown out of the blocks oil passage.
so that little opel was a total loss.
well as this little truck was a 4 speed as it was and i had a 283 small block sitting in the back of the garage. 2+2 = a vary fast truck..
i ran that truck like that for a good 10 years and later sold it to a friend who ran it till the rusted to the ground.
that silly thing got 25 mpg like that.

Little Mazda is cute.

That's her name now.

I just barely know enough about cars to change the oil. (Messy but WAY cheaper than paying a mechanic )

One thing I learned that some may not know. The mechanic does NOT clock in to work on your car. There is a set rate for "How long does it take to replace the framistat?". It used to be in a HUGE printed book, these days it's doubtless on the internet. There's doubtless pressure to meet or beat that time.

The Admiral touched on this but didn't go into details like "How do they pick the time for a given job?" For all I know, they use a ouija board to consult Henry Ford 1.

5703394
Yes, back in my youth, I had a friend that bought Grammy's Straight 6 Ford Maverick with under 10,000 miles on the engine. He took the engine out & traded it for a car with a small block V8 & a positraction rear end (and other stuff ICR) with over 100,000 miles on the parts that still worked. Over the course of the summer he managed to halve his gas mileage and triple his insurance rates.

His Grammy was VERY impressed. Not favorably impressed, but impressed. Especially when he called her to get him out of jail at 6 AM. (For some reason the cops had impounded his car, he lacked cab fare & didn't feel like walking 10+ miles down a backroad with a hangover to get home.)

:rainbowdetermined2:

But first, you know what to do:

Boop de snoot? :yay:

as the harmonic balancer

I can't tell if this is real or not. I mean, I trust you, but, well, harmonic balancer? Googling myself would spoil the fun.

My toolbox, loaded in the back of my truck some years ago

Is this one of those situations where the toolbox is worth more than the 4 wheeled beast used to transport it?

Got it all back together, ran pretty good and even better when I connected the ignition coil I forgot to plug in when I put it back together.

Some engines are picky, wanting all the coils back in the place they should be.

On this engine, the one we really shouldn't have skimped on was the harmonic balancer bolt.

I'm beginning to suspect that harmonic balancers are real. Maybe.

5703382

Glitter in the oil. That does not sound like happytimes at all.

The Mazda Miata was always a 'chick car' to me, along with the new VW Beetle. It's why my wife insisted we get one for our daughter when she graduated high school in 2015. PINK, of course. Good thing we opted for the gas engine because we found out later VW fudged the numbers on emission for its diesel engines and offered to "buy back" the cars.

As soon I read Ecoboost, that was enough.

Harmonic Balancers sound like the kind of tech an engine manufacturer adds to a big engine in order to fit on a smaller engines mounts to save costs, when they dont want to stick a serial hybrid in and call it quits?:trixieshiftright:

You forgot to add 'like and subscribe'. And we love you too n_n

5703418
aww yes the days of yesteryear. i kind of remember them.

That reminds me of the saying in my dad’s half of the family about Fords, “Family doesn’t allow family to drive/own Ford’s.” For whatever reason a large portion of that side has always had horrible luck when it comes to any Ford family vehicles.

5703383

how ever will I find that blog now!? Why it's not like I can just go to your blog posts and find it.

That's true, although I hid the resolution in a different blog about a different car. . .

5703394

when i was younger way younger i had a 1976 Chevy LUY truck with a tiny Opel 1.8 . i put a timing chain in that one summer after the old one broke. yep that was a full rebuild. ... i found that one of the anchor pins holding the timing slide rail had blown out of the blocks oil passage.
so that little opel was a total loss.

Ooh, that sucks. Not much you can do with that, honestly, and I doubt it's something that you could have foreseen.

Sometimes that's where our access to service information really helps out; we might not have seen something at our shop but somebody else on the internet has, and so we know what to look for.

well as this little truck was a 4 speed as it was and i had a 283 small block sitting in the back of the garage. 2+2 = a vary fast truck..
i ran that truck like that for a good 10 years and later sold it to a friend who ran it till the rusted to the ground.
that silly thing got 25 mpg like that.

That's impressive mileage for an old V8! Those LUVs didn't weigh all that much, which probably helped. I wouldn't be surprised if even with the V8 it was under 2500 pounds. Back where I used to live, they were using a LUV as a junkyard runner truck until it finally collapsed due to rust.

5703409
The pony drinking Coke? She's an OC, and her name is actually Fizzy Pop, although I do like "Little Mazda" as a name. I wonder how long after first contact foals would start to get car names?

5703415

I just barely know enough about cars to change the oil. (Messy but WAY cheaper than paying a mechanic )

I'd counter that a good mechanic looks at other stuff and might recognize a problem before you would. I'd avoid those quick-change places, though; while there are surely some good ones, a lot of them have very inexperienced or straight-up incompetent staff.

One thing I learned that some may not know. The mechanic does NOT clock in to work on your car. There is a set rate for "How long does it take to replace the framistat?". It used to be in a HUGE printed book, these days it's doubtless on the internet. There's doubtless pressure to meet or beat that time.

This depends on the shop, but it is a common arrangement. It is on the internet and there are also programs that shops use (such as Mitchell OnDemand) which give labor times. For a technician, being able to beat the labor times translates into better profits; when I worked at Firestone I usually worked 40 hours a week and got paid for 50-60 hours. Having a good service writer really helps, and sticking with jobs that you're good at also helps. However, flat rate can cut into the quality of the job, since the tech might want to rush things rather than take the time to do it properly. It gets complicated. :rainbowlaugh:

The Admiral touched on this but didn't go into details like "How do they pick the time for a given job?" For all I know, they use a ouija board to consult Henry Ford 1.

Manufacturers figure it out, I don't know exactly how. Sometimes they observe techs in the field (i.e., the dealerships) to see how they're doing jobs and how long they take. Sometimes the mechanics figure out things that the automaker didn't. Supposedly, mechanics figured out that to get the cylinder heads off on the 6.0 diesels, it was quicker to pull the cab off than do it the way the book recommended. Ford applied that idea to their next design of the trucks and made the cab come off easier (which I'm sure also saved money on the assembly line).

I suspect that the alternator replacement on the older Focus where you unbolt the engine from its mount, slide it forward, and get the alternator out that way was probably also discovered in the field. It sounds stupid, but it works really well.

Over the course of the summer he managed to halve his gas mileage and triple his insurance rates.

One of the reasons I've never owned a hot rod.

5703429
Usually it's get a drink and sit back, but snout-booping is also a valid answer.

Oh, man.
I just bought an electric car. A JAC E10X, a subcompact hatchback FWD.

It has a water cooled electric motor. The motor directly feeds into a differential, that then feeds into the front tyres. The motor itself has only one moving part: the shaft. I think the one mechanical weak link is the separate pump that runs the water between the motor and radiator. The car came without owner's manual, but it did come with a QR code if I cared to download the 210 page thing. The funny thing is that it genuinely just a user manual, going for ages about sitting position, how to use the plug, circumstances that will or won't fire the airbags, and driving technique. And some two dozen pages on vehicle maintenance that go on into smaller things, like how to properly wash a car, how to use a vacuum cleaner, and how to check radiator glycol and brake oil, as that's all that this car can be serviced by the owner. Anything more advanced is getting it back to the dealership every 10,000km, with about a hundred dollars in hand.

5703435

I can't tell if this is real or not. I mean, I trust you, but, well, harmonic balancer? Googling myself would spoil the fun.

It's a real part. It absorbs the vibrations from the engine and also keeps crankshafts from breaking.

cdn.discordapp.com/attachments/879533986303606834/1053495444547829820/861040_10201593315329299_135816701_o.jpg

My toolbox, loaded in the back of my truck some years ago

Is this one of those situations where the toolbox is worth more than the 4 wheeled beast used to transport it?

Considerably more, and the toolboxes are cheap compared to the tools that are in them. The current price for the big yellow box is $10,500 (I bought it used almost 20 years ago and paid a lot less than that). The truck was $300-- got it cheap because it had been on fire.

Some engines are picky, wanting all the coils back in the place they should be.

I know, right? It had five out of six working, it should have been happy with that.

Glitter in the oil. That does not sound like happytimes at all.

Glitter in the oil is not happytimes. Oil should not sparkle.

5703440

The Mazda Miata was always a 'chick car' to me, along with the new VW Beetle. It's why my wife insisted we get one for our daughter when she graduated high school in 2015. PINK, of course. Good thing we opted for the gas engine because we found out later VW fudged the numbers on emission for its diesel engines and offered to "buy back" the cars.

You might have done well if you'd gotten the diesel; a lot of the buyback offers and other settlement offers were more than the actual value of the car (this varied on the car's condition).

Miatas are actually fun cars to drive. They're short and lightweight and nimble, although not all that comfortable for a tall person. They're also fairly easy to work on. Plus they're rear-wheel drive, which is nice.

5703447

As soon I read Ecoboost, that was enough.

As much as I love picking on Ford, we've done a lot more expensive engine repair on late-model GM engines, especially the 2.4L and the 3.6L--both of those are unforgiving of not doing maintenance on time, especially since they consume oil and have long oil change intervals.

5703448

Harmonic Balancers sound like the kind of tech an engine manufacturer adds to a big engine in order to fit on a smaller engines mounts to save costs, when they dont want to stick a serial hybrid in and call it quits?

It's not just big engines that have them; little engines do too. One of the things that a harmonic balancer can do is prevent runaway harmonic oscillations in the camshaft, which can snap it.

Also, fun fact, a lot of the little inline fours have balance shafts in them, too, 'cause they're not a naturally-balanced engine. In fact, as far as I know, the only automotive internal combustion engine that is naturally balanced is an inline 6.

5703449

You forgot to add 'like and subscribe'. And we love you too n_n

I did forget that, didn't I?

I'll have to put that in next time 'round. :heart:

5703471

That reminds me of the saying in my dad’s half of the family about Fords, “Family doesn’t allow family to drive/own Ford’s.” For whatever reason a large portion of that side has always had horrible luck when it comes to any Ford family vehicles.

We were an all-GM family until the 90s; since then it's been whatever will serve its purpose the best. Right now my daily driver is a Dodge Caravan, 'cause they're the best domestic minivan.

I've only owned two Ford products. One lasted two days before suffering a failure that would have exceeded the cost of the vehicle, while the other did very well.

On the first, the repair was a broken inner tie rod end.

And before you wonder how that could cost more to fix than the car was worth, I intercepted both those Fords on their way to the junkyard. $50 for the first one, $200 for the second.

5703707
I wasn't disagreeing with you, I honestly thought the EcoBoost was a bad idea. You have pistons that aren't being used to convert combustion into mechanical power, that's just asking for an unnecessary repair bill. (No offense)

5703711
WAY back in the Dawn Of Time, Model T Fords had a Radiator & cooling system but no water pump. You fixed a leak by throwing some oatmeal (or similar substance) into the radiator. It would be drawn to the leak & the engine heat would cook it. Problem solved. :yay:.

Model A Fords had a water pump. You did that, you would clog the water pump & fry the engine. All the little moving parts would fuse into one big (unmoving) part.

My paternal grandfather didn't know this & kilt his Brand New Ford stone hot dead. Went back to the dealer & he just laughed. :rainbowlaugh: My grandfather DIDN'T laugh. After that, we were Chevy people for the next 50+ years.

Moral: In a free market with more than 1 choice, the customer thinks "They did me dirt." & you will lose a LOT of future business.

:trollestia:

5703692
Fair enough... I could use an excuse to reread some of your blogs anyways, they're both educational AND entertaining... and between them and "Just Rolled in" I'm never going to touch my own car if I get one.

As always interesting look inside a car (and work), thanks for this, Admiral!

I wonder what are your long-form thoughts about future of transportation in USA?

I tend to be on skeptical side, and there is everpresent debate about EVs vs more traditional ICE cars and hybrids at Charlie Stross's blog. Do you think car modification will be eventially allowed in at least some USA states? Because making new car is quite energy and material intensive... Will repair become easier in mid-term future, if people push for it?

Because to be honest I definitely do *not* want 'good' old times of widespread unqestioned human/animal exploitation to return for ...ever.

harmonic balancer

The name of this part gives such magitech horseword vibes.

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