Engine brake vs. Exhaust brake

[Beltane]

Technical question for those who know it. Just two words relating to the same thing? I mean, i know how an engine brake works, or at least i think i do.

Basically the fourth stroke is not completed, the exhaust gases not released by the valve and therefore counteracts piston movement which results in slowing down the truck. The higher the set stage of the engine brake, the more pistons are used to slow down. Feel free to correct me if i got something wrong. Would be more than happy to know it accurately.

But yea, question remain as i can see a relation between those words. Really the same or two different principles?

[Hypertext Eye]

What you described is what wikipedia calls an exhaust brake.

There is also a compression release brake (Jake brake) that opens the exhaust valve at the top of the compression stroke, so all of the energy from compression is lost. The engine has to expend energy to pull the piston back down.

[Nono54Fr]

My 2cents:

. Engine brake: the gas pedal is not actively pressed, the momentum of the truck is lost under its own weight by forcefully making the engine's parts move.

. Jake brake: the exhaust valves are open after the compression cycle (instead of staying closed before the ignition), losing the energy accumulated by the gases during said compression.

. Exhaust brake: valve(s) placed in the exhaust pipe to slow down the release of exhaust gases.

[Beltane]

Thank you very much, both of you. Looks like i really need to check on that topic a bit more closely. Not that i would have a problem with that, i am a sucker for mechanical specifications. For whatever reason, its not like my real life job is even close to that stuff ^^

[pieperjohanns]

Apparently the same words are used for different things, that doesn't make this engine brake thing easier to understand.

The truck that I once drove had a brake in the exhaust pipe like Nono described. It was a throttle valve that blocks the exhaust pipe, so the exhaust gases stay inside and slow down the engine. You would also use this brake to stop the engine when you park your truck. I thought it would be logical to call this thing exhaust brake.

There are at least two more engine brake types that work inside the engine, not inside the exhaust pipe. One being the jake brake and the other one being the one Volvo uses.

A bit of confusion with this subject is also caused by people thinking "using the engine brake" means just changing to a lower gear and letting the car roll, when instead the engine brake of trucks is an active system just like the service brake.

[MaximB]

So ETS2/ATS have only Engine Brake and Retarder?

[Nono54Fr]

Originally posted by MaximB:

So ETS2/ATS have only Engine Brake and Retarder?

. engine brake : occurs naturaly
. engine brake (bis) : aka jake brake or jacobs brake, combustion cycle altered
. Volvo engine brake : enhanced jake brake, combustion cycle twice altered
. main brake : pedal + air tank
. parking brake : push-pull button on the dashboard
. retarder : electrical, on the gearbox / driveshaft
. exhaust brake : valve in the exhaust pipe