OT: Engine quiz

The proportion.

Thank you, I don't need my personal information harvested.

Engine's work because there's a little man inside who turns a crank (on the crank shaft, naturally).

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www.wescottdesign.com

istics as the gasoline bit.

Steam stroke 6 can harvest most power when the engine runs flat out. But in terspersing an extra 2 lower power strokes works rather against the power/w eight ratio. At the low power end, steam will harvest nothing. Then there i s the fact that the engine needs to run hotter, away from its ideal operati ng point. Then there's the compatibility issue of water with spark plugs. I t has its uses, but like any engine design it has some real issues too.

on the cold side. It's bound to be seriously large, but the alternative is to run an open cycle, which wastes a lot of heat.

I don't see any reason that it would need to be seriously large. Get some d ecent speed going between gases and metal and the size shrinks very nicely.

NT

Maybe in New York. Not here.

If I say that I'm an engineer, the usual reply is "Cool, what do you do?" Being a hardware engineer is even better than being a software engineer.

Nerds and engineers are hot here. Guys are "brogrammers." Twitter and Square and Uber and Dolby HQs are a couple of blocks away, and jeans and backpacks are in style. Lots of she-nerds, too. They dress about like the he-nerds but with better footwear.

I was rounding the corner and four huge, hairy, mean looking, scary guys were blocking the sidewalk. I sneaked around them and one was yelling "DYNAMIC RESOURCE ALLOCATION!" They were geeks.

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John Larkin         Highland Technology, Inc 
picosecond timing   precision measurement  

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com

The classic issue about a steam engine isn't how big the boiler or the engine is. The problem is the condenser.

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John Larkin         Highland Technology, Inc 
picosecond timing   precision measurement  

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com

Run 'em open loop, like steam locomotives. Water's cheap.

Water vapor is a greenhouse gas and might be considered a pollutant: I can see the headlines now: "Steam powered vehicles accelerate global warming". Maybe a temporary ban on driving steam cars until the humidity levels drop to tolerable levels. Then, there's the mold and fungi growing on everything, paint that never dries, and chronic dirty window glass. Then, there's the noise produced by steam engines, which I've found to be far noisier than infernal combustion engines. Are you sure steam is a good idea?

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Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

At least as good as EVs.

So, what was your score?

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** So what is "longer" about the expansion ??

.... Phil

On Tue, 12 Jan 2016 20:20:26 -0800 (PST), Phil Allison Gave us:

They typically DO have a longer stroke, which yields a higher torque output per combustion cycle.

The higher compression is not the reason as the output of each combustion is less. That is why they boost it with a turbo. THEN there is a greater yield.

That's what I thought so I answered "it doesn't" and got it wrong. :( Otherwise 29.

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Rick

Not really. No one should care about MPG. We care about MPM - miles per money. Around here diesel is nearly 20% higher price per gallon, so costs more per BTU.

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Rick

A longer stroke for a given displacement means a smaller piston area and so less force on the piston. The two effects exactly cancel. Do the math.

The higher compression ratio is *exactly* the reason why diesel engines get more power. They also raise the compression as much as practical in high performance gas engines for exactly the same reason, higher output for the same size engine. Saying "each combustion is less" makes no sense.

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Rick

Yeah, some of the questions were pretty lame.

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Rick

I think the question was about configuration of cylinders, not engine types. The rotary engine doesn't really have cylinders.

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Rick

** It that were true, while making no other changes to an engine, simply increasing the stroke of the pistons would increase the power output at the same rpm.

This defies the conservation of energy and so is false.

Facts:

Increasing the stroke of an engine requires the piston surface area to be reduced by the same factor in order to keep the capacity the same.

A smaller piston area means less force is created by the combustion pressure: Force = Pressure x Area

Any increase in torque from having a larger radius on the crankshaft is cancelled by the smaller area and hence force from the pistons.

** The hotter combustion temp of a Diesel means more pressure hence and more torque at the same rpm.

... Phil

** FYI the word "longer" refers to either time or length.

Unless you are Humpty Dumpty.

.... Phil

On Wed, 13 Jan 2016 02:32:46 -0500, rickman Gave us:

Longer stroke IC engine produce more torque per unit displacement volume. Known fact. The piston is only smaller on compact automotive engines. Big diesels get away from the piston diameter base impact issue by having a longer rod and bigger block. So no smaller piston.

When someone strokes their race engine, they do not go sleeve it for a smaller piston, so displacement goes UP in that case as well.