diesel engines

[hondakiller]

i know it says anything not car related but this doesnt fit into a certain country. why do diesel engines idle so roughly but are smooth when the slightest throttle is applied?

[AndreyS]

Copression... They run at over 20:1.

[hondakiller]

so any engine with a high compression will cause bad vibration when it idles?

[AndreyS]

Gasoline engines won't be able to handle that kind of compression even at idle. As for higher rpm I think it's because of counter balancing...


Don't have that much automotive experience so anybody smarter should be more helpful.

[hondakiller]

sorry to sound like a dumb little kid but why cant they handle it?

[AndreyS]

Pre-detonation also known as pinging. Under high compression gasoline detonates under pressure even before the spark goes off means trouble, not exacly sure on what happens, perhaps somebody can fill me in.

[hondakiller]

o duh thats right they cant do it because of the octane limitations of street legal gas.

[RacingManiac]

Diesel actually runs on the Pinging on Gasoline engine. They haven't got spark plug. By running high compression, the diesel detonate when the piston reaches the top. Because of that, you can actually shut the engine off and it would still be running a couple of minutes more....

[hondakiller]

yeah they have glow plugs to get them started and their compression is so high that resulting heat ignites the fuel. thats a pretty cool idea.