Follow Slashdot stories on Twitter

 



Forgot your password?
typodupeerror
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×

Comment Re:I thought diesel ran cleaner (Score 1) 189

because it's important: exhaust gas volume is proportional to load.

Gasoline engines, yes, Diesel, no. As I posted elsewhere, Diesel engines have something closer to a fixed air intake on each revolution, irrespective of load.

Please read before replying.

Remember that Diesel engines use compression ignition and, without sufficient air, there is insufficient compression to ignite the fuel.

Would you like me to tell you about my AT185. or my OM617.951A?

Comment Re:I thought diesel ran cleaner (Score 2) 189

Typical compression ratio in a Diesel engine is somewhere around 20:1, vs a gasoline engine that's running 10:1 or there about.

So what?

Basically this is displacement/cylinder * compression ratio * RPM * number of intake strokes per revolution.

The compression ratio is a function of the head volume and the cylinder volume. It has nothing to do whatsoever with determining how much air is drawn into the engine, which is defined by speed, bore, stroke, and intake efficiency. It is rather determined by how much air is drawn into the engine, and how much space you have left for air at the end of a compression stroke.

Ever wondered why diesel tail pipes are a lot larger than gasoline ones? This is why, diesels move a lot more air.

Diesel tail pipes are a lot larger than gasoline ones because diesels shit the bed when you have backpressure. It ruins their efficiency and you have to play tricks to get it back. Turbocharging is worth it anyway because it's turbocharging. Now, pay attention to this part, because it's important: exhaust gas volume is proportional to load. Diesels have bigger exhausts because they have more torque. This is also why turbochargers and diesels go together so well. Turbochargers are driven by exhaust gas expansion, which as mentioned, is proportional to load.

If you carve the piston out, you lower the compression ratio, and you increase the amount of air the engine consumes. You in fact have this exactly backwards.

Comment Re:I thought diesel ran cleaner (Score 1) 189

Not when cruising at 65 mph. Not even close.

Well, tell us what it is. Neither of my turbos boost that high, but they're both old. (My F250 peaks out at 11 psi and my Mercedes at 12.) The F250 cruises at only around 2 psi unless you have a trailer, then it's more like 6 or 7. The Mercedes cruises at around 7 or 8 psi. But they have much lower boost pressure than modern diesels.

Comment Re:So much for biodiesel use... (Score 1) 189

And still has a hell of a lot of particulate emissions, negatively impacting air quality in major cities, which you might note are the entities banning the diesels here.

Gasoline has just as much particulate emissions as diesel. It's just a smaller soot particle which we couldn't accurately measure until recently. Of course, DPFs on diesels reburn the soot until it's a small, invisible particle just like gasoline, making it just as dangerous as gasoline.

Banning diesel is not the remedy. Banning combustion is the remedy. Banning diesel is just stupid.

Comment Re:Democrats are the enemy (Score 1) 549

They're all going to agree to never lobby for foreign entities, and go half a decade after they leave office before they can do that work domestically.

Guess what? Those agreements are unconstitutional and won't stand. That's like a Californian signing a non-compete agreement. Okay! Sure!

Comment Re:OK, now pull the other one (Score 1) 501

Actually, it's nowhere near that simple. For example, my wife is a "stay-at-home mom". Thus she's on the "bad" side of the labor force participation rate.

The numbers of "stay-at-home moms" includes women who are doing it because they cannot find work.

She's doing this because 1) we think it's better for our younger-than-school-age kids, and 2) she can't make enough to pay for the daycare we would have to buy.

She chose to be unemployed rather than underemployed? Thank you for making my point for me.

Comment Re:Plenty of low-wage jobs to go around... (Score 1) 501

Well, I have no great love for CNN, but I liked the look of this article. Let's see, there's a Forbes link on millenial underemployment, let's skip that one just in case. Hmm, there's an article on Monster with... no date? hmm, can't cite that. Here's one from time which says 46% of Americans Say They Are Underemployed, that's a fun idea. The federal reserve's estimate is "fairly close to the trend derived from CPS data, but at a much higher level".

IOW, the direction of trend is accurate, but the numbers are bullshit. Like always

Comment Re:I prefer emby... (Score 1) 81

I have just read about emby after reading your comment, and it has made me excited. Not in the TMI way, but in the this might be what I am looking for way, even though it depends on Mono. I'm going to download an Ubuntu image for my Pine A64+ stat. Hopefully that has enough gusto to do what I want to do with it. The data is already connected to the network via another ARM SBC (a pogoplug) which also has GigE.

Comment Re: If a drone came in your yard uninvited ... (Score 1) 44

"Nobody knows where all these cool drone parts came from. There's a chassis over there in the dumpster of the Shell Station on Richmond Street with a scratched off label. Nobody know how it got there."

No doubt if nobody saw you do it, you're golden. On the other hand, Slashdot is going to get a subpoena for logs if someone actually does find a scratched off label in the dumpster of the Shell Station on Richmond Street one day...

Slashdot Top Deals

APL is a write-only language. I can write programs in APL, but I can't read any of them. -- Roy Keir

Working...