Engine Brake / J Brake

...it's not unique to the UK...

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Didn't mean to suggest it was; Just trying to draw a parallel to your "Kleenex" example, and there are lots more like it.

Tom said:

Didn't mean to suggest it was; Just trying to draw a parallel to your "Kleenex" example, and there are lots more like it.

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Yes, that's certainly true. I wonder if brand owners hope for that to happen, or cringe at the misuse of their trademarks/copyrights when it does...

Well, its certainly worked out well for the Crescent Tool company, or the Channel-lock brand name.  Or the Coca-Cola company for that matter.

Lots  of similar examples.

OTOH some product names don't translate across the Atlantic:

- Had to remember that Milky Way changes to Mars Bar, and other candies change name.
- A US component company developed a "rugged" line of products they branded as 'Durex'. The UK sales and marketing folks, who had not been consulted, were horrified, and customers thought it was a joke; That was the major brand name for condoms in the UK 

Jacobs says the term "Jake Brake" can be used for all Jacobs braking products, but not all such products in general. At least that's their official position...

http://www.jacobsvehiclesystems.com/faqs/view/4/

There ya go, discussion settled...  ;D

Tom said:

Lots  of similar examples.

OTOH some product names don't translate across the Atlantic:

- Had to remember that Milky Way changes to Mars Bar, and other candies change name.
- A US component company developed a "rugged" line of products they branded as 'Durex'. The UK sales and marketing folks, who had not been consulted, were horrified, and customers thought it was a joke; That was the major brand name for condoms in the UK 

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Reminiscent of when Esso changed to Exxon, or Chevy's Nova bombed in Spanish lands (No Va=No Go).

Larry N. said:

...Chevy's Nova bombed in Spanish lands (No Va=No Go).

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Actually, that's an urban myth... While "No va" can be translated as "No go", "Nova" is a distinctly different word. Chevy's sales of the Nova in Mexico were on target and even exceeded expectations in Venezuela. Nor did they change the Nova name as is often reported as part of the myth. Even Pemex, the Mexican government owned gas monopoly, uses the "Nova" name as one of their gasoline brands.

http://www.snopes.com/business/misxlate/nova.asp/

Interesting Cummins retarding figures

http://www.jacobsvehiclesystems.com/files/media/Product/Model%20Intebrake%20Sell%20Sheet%20-%20final%20copy.pdf

Tom said:

The butterfly in the air intake, when closed, provides back pressure in addition to shutting off air. See here. The back pressure acts in a similar way to the flap in an exhaust brake on a diesel.

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Closing the throttle on a gasoline engine does indeed shut off most of the air flow into the engine. However, it causes a VACUUM to be developed in the engine, not pressure. It is the pistons working against that vacuum that develops the braking effect in a gas engine.

In a diesel there is no such restriction in the air intake. It is open all the time. Power is controlled by metering the amount of fuel which is injected on each power stroke. Since there is no air restriction, no vacuum is developed in a diesel when the throttle is closed. As the pistons move up and down, they are just moving air. The air that is compressed on the compression stroke provides no braking effort because that same air returns most of the energy of compression when the piston starts back down on the power stroke. That's why a diesel requires some kind of additional device to generate braking force.

An "exhaust brake" is nothing more than a butterfly valve in the exhaust which shuts off the flow of exhaust. This builds pressure in the exhaust pipe and in the cylinders, thus developing some braking effort.

The "compression brake" or "Jake Brake" dissipates the energy in the air that is compressed on the compression stroke in a diesel. It changes the timing of the exhaust valve so that it opens when the cylinder is at the top of the compression stroke. All that compressed air in the cylinder is suddenly released with a "bang" which is why an un-muffled Jake Brake can be pretty loud. The energy in the compressed air is dissipated, with the result that the engine develops quite a bit of braking effort.

A little aside.  Most of the little towns around here have signs saying "No Jake Brakes".  Went through one yesterday that the sign said "No Engine Braking Devices".

I always used to worry that I'd get stopped on my old Shovelhead with drag pipes.  That thing was way louder than any jake brake, by any name, but they always just left me alone.

Old_Crow said:

A little aside.  Most of the little towns around here have signs saying "No Jake Brakes".  Went through one yesterday that the sign said "No Engine Braking Devices".

I always used to worry that I'd get stopped on my old Shovelhead with drag pipes.  That thing was way louder than any jake brake, by any name, but they always just left me alone.

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Jacobs Vehicle Systems asks that those "Jake Brake" signs and locations be reported to them so they can enforce their "Jake Brake?" trademark rights...

Jacobs Vehicle Systems FAQ

The Jake Brake on my former coach didn't make enough noise for any local citizen to complain or LEO to notice.

  OEM  muffler compression brakes noise is about 2-3 times the noise of the normal exhaust noise according to noise cops when the checked my truck. Can't remember decibel differences. Still an acceptable level and shouldn't bother anyone. Signs are for the straight pipe hot doggers   
  When your sitting 35'+ away from exhaust in a dp, it's really quite.