Engine break vs exhaust break

[RSchwarzli]

What is the differance between Cummins new exhaust break on the 600 engines, and Ferd's new engine break on the new power joke? Is there a differance? When we put a brake on our trucks, what do we put on?





Robert

 

[ARedetzke]

We put on exhaust brakes. They are simply a butterfly valve in the exhaust pipe, usually bolted to the back of the turbo. I'm not real sure about an engine, or "jake" brake. I believe it's called a Jake brake because a company named Jacobs makes them. As for how they work, I think that they actually close the exhaust valves on each cylinder during the exhaust stroke, thus being called an engine brake. The exhaust brake just creates a lot of back pressure. If I'm wrong about the engine brake someone chime in.

AJ

 

[bmoeller]

The exhaust brake is different animal than a Compression brake (Jake). On the Ford, they have a butterfly valve to help warm up the engine in cold temps. Western Diesel has a controller that can actuate it, to use as an exhaust brake. Same principle as a regular exhaust brake.



ARedetzke is sort of on the right track with the compression brake. However, it works works like this- It OPENS the exhaust valve right before the fuel is injected. It basically turns the engine into a big air compressor, hence the noise when turned on. The air is being compressed as it normally would be, but no power is being created. The compression brake has more braking horsepower than an exhaust brake.

 

[Paychk]

Actually the Jake opens the exhaust valve at the top of compression stroke instead of firing the injector.

 

[RSchwarzli]

Ooooooooooooooohhhhh. Its like that. Thanks. I feel so smart now.

 

[Paychk]

Wonder what it would do if the fuel were injected any way?? Maybe some neat pyrotechnics or just a melted turbo??

 

[dpuckett]

Ok, I was aware of the Exh valve opening at the top of the compression stroke, (hence the flatulent noise) but I didnt know the fuel got shut off. I thought fuel got injectoed, just the amount for idle? You know, enough to make the piston travel back down.



The exhaust brake makes back pressure, as stated. Enough, that with sotck valve springs on the 12valve, they can be forced open by the back pressure, forcing the valve to go into the piston as the piston comes up, bending or breaking something.



Daniel

 

[Paychk]

The piston travels back down the bore because it is driven by the rear wheels. No fuel is injected because one of the input conditions that is required to actuate the brake is no fuel ie. foot off throttle. More info here:



http://www.jakebrake.com/content.php4?doc_uid=17#FAQ10

http://www.jakebrake.com/content.php4?doc_uid=17#FAQ11

http://www.jakebrake.com/content.php4?doc_uid=17#FAQ12