E Brake question

[Cobra]

I recently had a Jacobs exhaust brake installed on my 01 RAM 2500. During converstion at the local coffee shop, an aquaintance who is a retired truck driver told me there is an exhaust brake and an engine brake. The exhaust brake works on the manifold and the engine brake works on the valve springs inside the engine itself.

It really isn't important cuz I got what Cummins specifies and I am happy, but I would like to know and I don't.


01. 5 RAM 2500 4x4 QC, 5 Spd, 3. 54 LSD, Patriot blue/silver, Jacobs brake, Westin stainless nerf bars

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Bill Kute

 

[MCummings]

Oh What Fun.

I THINK that a REAL "JAKE Brake" is operated by either holding the exhaust valves open, or maybe closed,, or was it the intake valves?

WHOA, But I know how a E-Brake works.

It shoves an Idaho potato in the pipe. Then when you want to go again, it throws it away.

My $0. 015

MerrickNJr

 

[Utah Willie]

From what I have read, the exhaust brake closes off the exhaust, thus pressurizing the engine to around 35 PSI which effectively turns it into a compressor as there is nowhere for the exhaust to go. The engine brake opens the exhaust valves near the top of the compression stroke which uses the high compression ratio of the diesel as a "brake". If the valves were not opened then, the braking effect achieved by the compression stroke would be negated by the squeezed air pushing on the down stroke. The great thing about the engine brake is that it can be used incrementally on two, four or six cylinders and it maintains engine heat on the downgrade. Gas rigs have the throttle plate closure to create a vacuum to accomplish a similar reaction but that tends to suck oil through rings and such to leave a trail of grey smoke on higher mileage engines.

 

[Gizmo 007]

A "jake brake" holds the exhaust springs open on the larger trucks (18 wheelers). I helped install one on a 1984 model Kenworth that has a Cummins (what else #ad
). At least that's what it does on this truck.

The "jake brakes" also work a lot better that the exhaust brakes. Maybe someone should contact Jacobs about building a kit for our Rams #ad
.

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2001. 5 3500 4x4 ETH/DEE 3. 54 LSD, HD transfer Case -- Quad Cab, Patriot Blue, Everything but leather #ad
, modified 6-way turn signal conversion (thanks Evan), K&N, 275's, PS boost module,
Real back-up lights, muffler and res. got knocked off in an off-roading incident (he he).
What silencer ring? #ad


Forget warranty -- BOMBS AWAY! #ad
#ad


[This message has been edited by Gizmo 007 (edited 05-16-2001). ]

 

[Ray Torresdal]

Jake brakes are great fun, but do you see all the towns and cities with "no Jake brake" signs posted at city limits? It would make me want to bring a rig into town with an air starter and shut it off for a few minutes. "Hey, officer, I need to start it to get it out of your way!"

cheers!

ray

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01 QC LWB 5 spd, trailer tow pkg, camper pkg
VA, PS boost module and elbow, PS heater saver