Internal Combustion Engine • Hacker News Board

Re: Internal Combustion Engine

#211

Post by Prcmaker » Fri, Apr 30, 2021, 11:50 PM UTC

gtvwill wrote: post #166

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…

> "I use inches here because in machine work thousandths of inches is the language du jour." Yeah not in Australia unless your machinist is >50 years old. Metric is more accurate/easier/less prone to mistakes. Metric is what we use.

I was trained in Australia, in the past decade, and was taught thoroughly in both metric and imperial. The engineers and machinists I have worked with that insist metric is the only way habe been more prone to mistakes when imperial components pop up, as they do. Accuracy is down to the spec, the person and the machine, ease of use is identical when decimal inches are used, mistakes are a result of poor communication.

Re: Internal Combustion Engine

#212

Post by baybal2 » Fri, Apr 30, 2021, 11:51 PM UTC

czinck wrote: post #147

elihu wrote: post #121

Earlier quoted context omitted.

I don't think cats are to address greenhouse gasses; they're focused more on reducing pollutants that affect local air quality and human health. The main greenhouse gas from a car is carbon dioxide. The amount you create is directly proportional to the amount of fuel you burn. I don't know why modern cats are expensive; it might have to do with the price of platinum, palladium, and so on, and the relative amount of t…

> I don't think cats are to address greenhouse gasses; they're focused more on reducing pollutants that affect local air quality and human health. I thought the same thing, but interestingly that's only kinda true. If anything, cats increase CO_2 as a desired end goal, because it's better to have CO_2 than CO or NO_x (or so the EPA has decided, I am no where near qualified to decide that). The issue with running too…

Diesels with combined SCR-EGR can go below US limits rather easily.

Re: Internal Combustion Engine

#213

Post by nemo44x » Fri, Apr 30, 2021, 11:51 PM UTC

What are the odds 50 years from now, the ICE becomes a hobby of the upper middle and upper classes? Much like analogue audio recording is becoming.

Re: Internal Combustion Engine

#214

Post by catmanjan » Fri, Apr 30, 2021, 11:52 PM UTC

therein wrote: post #208

I have always wondered, if it would be possible to make a small enough internal combustion engine so that you could just have it laying around in an apartment, sitting a few feet away from you, powering your appliances or charging a 12V or 24V battery. Dispensing the exhaust through a long tube. If all goes well, complete combustion of propane should yield CO2 instead of CO anyway. An additional enclosure shouldn't b…

Washing machines and other appliances used to be powered by ICE when the grid was not widespread

Re: Internal Combustion Engine

#215

Post by nemo44x » Fri, Apr 30, 2021, 11:53 PM UTC

therein wrote: post #208

I have always wondered, if it would be possible to make a small enough internal combustion engine so that you could just have it laying around in an apartment, sitting a few feet away from you, powering your appliances or charging a 12V or 24V battery. Dispensing the exhaust through a long tube. If all goes well, complete combustion of propane should yield CO2 instead of CO anyway. An additional enclosure shouldn't b…

Wouldn’t it be loud as hell? Even 4-stroke small engines are inefficient all things considered.

Re: Internal Combustion Engine

#216

Post by Prcmaker » Fri, Apr 30, 2021, 11:53 PM UTC

kokanator wrote: post #157

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…

Anyone who has the inclination to build an engine, should. It is super rewarding not to mention you get to buy a bunch of really cool tools. I build a 350 Windsor from the block. The research and design decisions were one of the best parts of the project. Then to put it all together and realize the power was amazing.

Ford (Aus) 4.0 was a great first build for me. I'm now taking my time on a Toyota 4K 1300cc, learning a lot more, and taking the time to design new components for it. Can't recommend it highly enough, though not for everyone to be sure.

Re: Internal Combustion Engine

#217

Post by sssilver » Fri, Apr 30, 2021, 11:54 PM UTC

Wonderful page. Here's something a bit more poetic on the subject: The man behind the smallest V-12 engine in the world[0]

[0] https://www.youtube.com/watch?v=c1pJIVqCC1E

Re: Internal Combustion Engine

#218

Post by nemo44x » Fri, Apr 30, 2021, 11:55 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…

If you’re not cheating you’re not trying.

Re: Internal Combustion Engine

#219

Post by CRConrad » Fri, Apr 30, 2021, 11:56 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…

> I use inches here because in machine work thousandths of inches is the language du jour.

I'll make a wild guess: In the USA.

EDIT: Heh, sorry... See https://news.ycombinator.com/item?id=26991690 . This time I really thought I'd checked, but there was lots of catalyst talk in between.

Re: Internal Combustion Engine

#220

Post by MAGZine » Fri, Apr 30, 2021, 11:57 PM UTC

mrfusion wrote: post #189

Isn’t it risky for the timing to rely on a rubber belt? Does it never slip? Even a mm of slippage seems like it would make the valve timing stop matching the pistons?

The belts are finely machined to very small tolerances, and things are tightened to specific foot-pound tolerances to make sure they sit exactly where they need to. So no, nothing slips.

I just went through a belt change with my brother not long ago. The tolerances you're dealing with are measured in thousandths of inches. Something that wasn't installed quite straight can cause almost imperceptible wobble that can destroy things under load.

Still, every day shop tools will help you get the precision you need.