Internal Combustion Engine • Hacker News Board

Re: Internal Combustion Engine

#91

Post by mywittyname » Fri, Apr 30, 2021, 8:56 PM UTC

tmh88j wrote: post #55

specialp wrote: post #41

Earlier quoted context omitted.

I built an LSX (Aftermarket GM) iron block engine (V8 LS) for a CTS V. I had to get some very precise tools (Have to measure to 10,000ths) or they were useless for bearing clearances and verifying cylinder diameters. My cylinders were 4.155 bore, and the bearing clearances were around 1.8 thousandths. Forged pistons, rods and crank. I had cracked a cylinder/piston on the original LSA. I did not trust anyone to do the…

>I had cracked a cylinder/piston on the original LSA. I did not trust anyone to do the work so I did a lot of research and did it all myself I love working on cars so I totally get wanting to do that, but why didn't you trust someone else to do the work? There are probably more reputable LS builders across the US than any other engine family.

It helps that they are abundant (in the hundreds of millions units produced), have been in use for decades (since the mid-50s), and are simple to work on (as evidence by the OP randomly learning to machine one).

As cool as 2-atom thick plasma transfer wire arc cylinder liners are, that's not something which will ever be available to a layman.

Re: Internal Combustion Engine

#92

Post by kccqzy » Fri, Apr 30, 2021, 8:57 PM UTC

specialp wrote: post #15

I just built an engine for my car. One thing I gained an appreciation for was how CHEAP cars and engines are. There's probably nothing else with as precise machining that is as inexpensive. Engine cylinders are honed to accuracies that are less than 1 thousandth of an inch. Crank journals as well and rod journals. This is all precise machine work with metal. I use inches here because in machine work thousandths of in…

> One thing I gained an appreciation for was how CHEAP cars and engines are. There's probably nothing else with as precise machining that is as inexpensive.

Not to denigrate the amount of engineering that went into car engines, but literally, what about chips? Devices that contain billions of transistors, arranged precisely on the order of nanometers. Yet they cost only hundreds of dollars.

Re: Internal Combustion Engine

#93

Post by esaym » Fri, Apr 30, 2021, 8:57 PM UTC

elihu wrote: post #47

specialp wrote: post #15

I just built an engine for my car. One thing I gained an appreciation for was how CHEAP cars and engines are. There's probably nothing else with as precise machining that is as inexpensive. Engine cylinders are honed to accuracies that are less than 1 thousandth of an inch. Crank journals as well and rod journals. This is all precise machine work with metal. I use inches here because in machine work thousandths of in…

The raw materials may continue to cost more for EVs. Motor windings are generally copper, and batteries contain lithium and (usually) cobalt and nickel. Permanent magnet motors sometimes contain rare earths. One could make an EV with aluminum motor windings and electrical cabling, no rare earth magnets, and lithium iron phosphate batteries. That would keep expensive materials to a minimum. EVs don't need a catalytic…

> EVs don't need a catalytic converter, so that's a big thing in their favor.

I feel there is some sort of scam going on with catalytic converters for the last few years. I actually worked in a small family owned auto shop in the early 2000's. If a car came in with a clogged cat, we'd first fix the source of the issue (usually a mis-firing cylinder allowing raw fuel into the exhaust) and then we'd cut out the cat, and weld in a universal fit one that we'd get from the auto store for $20. Then charge the customer $200-$400 for labor. I still see universal fit ones[0] although they are $80 now. But still, if you aren't dumping raw fuel or oil into your exhaust, cats are basically good for 300k+ "normal" driving miles. I assume they are expensive now because they are all mostly specially made/custom fit since all car manufactures keep cramming bigger and bigger engines into smaller and smaller spaces.

And while I'm ranting, there's always a negative for every positive and no doubt for the catalytic converter. For a catalytic converter to convert "greenhouse gases", the engine has to be burning fuel at a perfect air:fuel ratio of 14.7:1. While cruising down the highway, an engine could easily save fuel by running a more lean mixture, but this would cause more "greenhouse gases" to go out. So choose your poison I suppose.

[0] https://imgur.com/a/7X0sPlk

Re: Internal Combustion Engine

#94

Post by samstave » Fri, Apr 30, 2021, 8:58 PM UTC

BrentOzar wrote: post #61

jborichevskiy wrote: post #57

Earlier quoted context omitted.

> "What? The fuel tank capacity can't have an inflated basketball in it that springs a leak during the race, leaving us with more fuel capacity?" Pardon my ignorance- what is the motivation for temporarily reducing the fuel capacity in this example? And why was it disallowed?

Your fuel tank was only allowed to hold a certain amount of fuel because if you had more, you could go farther between pit stops, thereby covering more laps while the other drivers were stopped for gas. He would temporarily meet the small tank regulations during inspection, but under race conditions, the ball would burst, allowing for more space in the tank, which would get filled up with more fuel than his competito…

How was he "caught" if thats the term?

Re: Internal Combustion Engine

#95

Post by ianai » Fri, Apr 30, 2021, 8:58 PM UTC

admax88q wrote: post #49

mfer wrote: post #38

Earlier quoted context omitted.

If people were willing to pay the higher cost for the same feature set, why would they well them for cheaper? Why not pocket the extra profit? I don't like this line of thinking but I'm sure it's going to or already is happening.

... Because the whole nature of market competition? People will still choose the cheaper option if its available.

I’m starting to think it may just be minimizing cost. Theoretically that just means “maximize profit”, but I suspect in practice it means a whole slew of bad behavior and design choices. I.e. Pay for the part that’s .0001 cent cheaper than another option, despite the cheaper part possibly being a fire hazard.

Re: Internal Combustion Engine

#96

Post by esaym » Fri, Apr 30, 2021, 8:58 PM UTC

Robotbeat wrote: post #86

elihu wrote: post #47

Earlier quoted context omitted.

The raw materials may continue to cost more for EVs. Motor windings are generally copper, and batteries contain lithium and (usually) cobalt and nickel. Permanent magnet motors sometimes contain rare earths. One could make an EV with aluminum motor windings and electrical cabling, no rare earth magnets, and lithium iron phosphate batteries. That would keep expensive materials to a minimum. EVs don't need a catalytic…

Tesla already uses aluminum for power cabling because it’s cheap and lighter weight. Tesla Model S were induction motors (at first at least) with no rare earths, and Tesla is partnering with CATL for lithium iron phosphate batteries in lower cost versions of, if I believe, Model 3 and Y.

Note to replace copper wiring with aluminum, you have to go up at least one gauge size.

Re: Internal Combustion Engine

#97

Post by outworlder » Fri, Apr 30, 2021, 9:01 PM UTC

whatever1 wrote: post #40

Viker wrote: post #25

Earlier quoted context omitted.

Hmm... Hard to beat that energy density when the workload is large. Trucks, tractors, planes, ships. Sure consumer cars will be EV but ICEs are not going anywhere

People have hard time grasping how much energy chemical bonds can hold. 15 gallons of gasoline store 500kWh of energy. That is 5 tesla model s worth of energy. Efficiency plays role for our day to day car tasks, but when you have to deal with external forces or higher requirements of momentum, then you need more energy period. Towing, beating high-speed drag / waves, climbing high, cannot be addressed with smarter de…

> 15 gallons of gasoline store 500kWh of energy. That is 5 tesla model s worth of energy.

Yes. However, the Carnot efficiency means that most of it is lost as heat. Suddenly the advantage is not that large anymore.

Re: Internal Combustion Engine

#98

Post by tmh88j » Fri, Apr 30, 2021, 9:01 PM UTC

londons_explore wrote: post #62

kirse wrote: post #37

Earlier quoted context omitted.

Pure EVs will reach a fundamental peak percentage similar to any other car class... Hybrid powertrains are really where the next 20-30 years are headed for the bulk of vehicles. Automotive racing and supercars have demonstrated hybrids are the most effective setup for the past decade, and barring some major breakthrough in battery tech that will all trickle down into consumer cars over the next 0-20 years.

As soon as governments get serious about CO2 emissions, Hybrid powertrains will end up as a "worst of both worlds" position. Already across most of Europe all subsidies and discounts that applied for "eco friendly cars" no longer apply to Hybrids. That leaves few people wanting to buy a hybrid - it won't be cheapest or most eco friendly.

Not sure I agree with that. I don't think you realize how many cars have switched over to hybrid powertrains, but are not advertised as a main selling point like the Prius or Volt. Volvo's entire lineup is now hybrid or electric along with their new performance brand Polestar. Mercedes is switching over to hybrid powertrains even on their AMG models. Audi's using hybrid powertrains even on their highest performance models like the RS6 and their ultra luxury vehicles like the A8. Hybrid technology is great for sports cars and offers many advantages over fully electric, most importantly being the weight savings.

Re: Internal Combustion Engine

#99

Post by specialp » Fri, Apr 30, 2021, 9:01 PM UTC

kccqzy wrote: post #92

specialp wrote: post #15

I just built an engine for my car. One thing I gained an appreciation for was how CHEAP cars and engines are. There's probably nothing else with as precise machining that is as inexpensive. Engine cylinders are honed to accuracies that are less than 1 thousandth of an inch. Crank journals as well and rod journals. This is all precise machine work with metal. I use inches here because in machine work thousandths of in…

> One thing I gained an appreciation for was how CHEAP cars and engines are. There's probably nothing else with as precise machining that is as inexpensive. Not to denigrate the amount of engineering that went into car engines, but literally, what about chips? Devices that contain billions of transistors, arranged precisely on the order of nanometers. Yet they cost only hundreds of dollars.

Yes you are referring to another insanely complex thing that is very cheap relative to making one of cost due to mass production. But it isn't machined metal :) I didn't say I don't appreciate electronics too.

Re: Internal Combustion Engine

#100

Post by elihu » Fri, Apr 30, 2021, 9:02 PM UTC

Robotbeat wrote: post #86

elihu wrote: post #47

Earlier quoted context omitted.

The raw materials may continue to cost more for EVs. Motor windings are generally copper, and batteries contain lithium and (usually) cobalt and nickel. Permanent magnet motors sometimes contain rare earths. One could make an EV with aluminum motor windings and electrical cabling, no rare earth magnets, and lithium iron phosphate batteries. That would keep expensive materials to a minimum. EVs don't need a catalytic…

Tesla already uses aluminum for power cabling because it’s cheap and lighter weight. Tesla Model S were induction motors (at first at least) with no rare earths, and Tesla is partnering with CATL for lithium iron phosphate batteries in lower cost versions of, if I believe, Model 3 and Y.

I thought CATL makes lithium iron phosphate batteries, and lithium sulfur hasn't been commercialized yet. Unless there's some news on that front I missed?

I think induction motors tend to be less efficient than permanent magnet motors (and thus require more cooling). The Netgain Hyper9 (a popular motor for conversions) is a permanent magnet motor which doesn't use rare earths. It's very efficient but not particularly powerful (though that may be due more to the relatively low voltage it runs at).

That's cool that Tesla is using aluminum for power cables. Makes sense to save cost and weight where you can.