Exhaust Brakes

[James68352]

Does anyone know of a site that I can check out that gives an overall explanation of how an exhaust brake works exactly?

Thanks,

Jim C.

[Big Blue dsl]

check out jakebrake.com it is the official sit for jacobs they make the jakes on big diesels and they have an explanation of how they work.

[James68352]

The following is from the FAQ section of jakebrake dot com :


Do you make a product for the Ford 7.3L Powerstroke or Navistar International T444E engines?

ANSWER:

No, Jacobs does not offer an exhaust or engine brake for these engines in fact, Navistar and Ford have requested that we do not develop one for these engines.
The primary concern with putting a retarder on these engines is their use of hydraulic lifters. Most engines with hydraulic lifters have fairly low exhaust back pressure limits so the performance of an exhaust brake would not be substantial. More importantly the use of an exhaust brake on an engine with hydraulic lifters can cause engine damage. The problem is that the increased back pressure resulting from the operation of the exhaust brake will cause some degree of valve float. This valve float can cause the hydraulic lifter to re-set with the valve still open (not seated). This phenomenon is known as lifter jacking. Lifter jacking could also result if a traditional engine brake were used on these engines. The results of lifter jacking can be anything from low positive power (because the valves stay open) to engine damage caused by valve to piston contact.


I realize that these are different engines than the chevy diesels but the part about the hydraulic lifters caught my eye. It made me wonder how an exhaust brake would affect my 6.2. I am not sure if it has solid or hydraulic lifters (the motor is still stock).

Jim C.

[john8662]

The 6.2 and 6.5 both have hydraulic roller lifters.

Based on the information you've found, I wouldn't implement an exhaust brake on my rig. But, I've never been a fan of exhaust brakes at all.

[Craig M]

Exhaust brakes or engine brakes are great for engines that are designed for them. But as the Jakebrake explanation states, used in vehicles not originally designed for them may create some issues.

[Peter J. Bierman]

This is interesting, couse I never read anyting about this engine damage from people who have a exhaust retarder like the one BD sells.
I guess you need a lot off backpressure to keep a valve open against the valvesprings :eek:

If you have a non lockup converter, it will not be as effective as with a solid connection between engine and driveline.

Peter

[arveetek]

The "jake brake" is actually an internal engine modification that basically turns it into a big air compressor. These are used on the big rigs and give the loud popping noise you hear when they slow down.

Most exhaust brakes designed for pickup trucks, medium dutys, and motorhomes are simply a butterfly valve plumbed into the exhaust system. They've been making them for years for all types of diesel engines. I believe that the companies that make them design them to deliver only a certain amount of backpressure, enough to slow the rig down but not enough to hurt the engine.

The Cummins doesn't have hydraulic lifters, but I have read that you might want to install heavier valve springs when installing an exhaust brake. I know that BD makes an exhaust brake for the 7.3L and 6.0L Power Strokes, and the 6.6L Duramax. I don't know, however, if they recommend any valve spring changes or other internal modifications for these engines.

I don't believe that any company has produced an exhaust brake for the 6.2L/6.5L engines. It wouldn't be hard to retrofit one in, but I don't know if it would be a good idea or not. I'm not sure if anyone has done any research on how much backpressure the 6.2L/6.5L can stand before it starts floating valves.

Also, most exhaust brake kits also include a torque converter controller that allows the user to lock up the converter in all gears while slowing down. A lot of stock vehicles unlock the converter when letting off the throttle. This wouldn't do you much good, as Peter said. An exhaust brake on a vehicle with a TH400 tranny, for example, wouldn't help nearly as much as one with a 4L80E, in which the TC could lock up and transfer all forward motion to the engine. A manual tranny would be even better.

As an interesting side note, the 7.3L Power Stroke engine has a butterfly valve already mounted in the exhaust system, known as the EBPV, exhaust backpressure valve. It's used to help warm the engine up on cold days. You can buy a wiring kit that gives you manual control over the valve and turn it into an exhaust brake. I installed one on a friend's 96 F-250, and he really liked it. It also included the aforementioned TC controller. He used it towing his 5th wheel for a couple of years without any problems before he bought a new truck. I don't hear much about this anymore, I'm not sure why.

Casey

[Dezman125]

Hi
I belive that someone does make a engine brake for the 6.5 turbo.I read an artical on it in the DP 1997 bound articals.The picture that is at the begining of the artical was taken on our main street.I belive it was a BD brake,but i'm just going on memory.
I'd like to know if anyone has tried to use one on the 6.2.I was thinking of adding one to my truck once i have my turbo system fabed up.

[Ratau]

What was the original purpose of the butterfly devise on the left manifold and how much backpressure will it create.

Danie

[James68352]

I believe that the butterfly valve you are asking about is only on the 6.2c motors with the EGR. I think that it is only to help the motor start and works along side the EGR.

After the discussion and some research I decided that I won't be putting an exhaust brake on my 6.2 truck. Maybe in the future if I do a complete build I will do it in a way that an exhaust brake would be alright on the valve train.

Thanks for the info everyone.

Jim :D