Using jakes on long downhills

All a jake is, is a big valve body on top of your valve train that opens the exhaust valve at the top (or near the top) of the compression stroke...the only thing that might wear is the roller that rides on top of the exhaust rocker that does the work.

 

Ops you forget that crank and camshaft working as hard as on hard drive

 

You mean the reduced forces on the crank compared to a loaded return stroke? You have no idea what you're talking about.

 

Not possible. Here is why. With the engine brakes on during long downhill grades the exhaust flow cools the aftertreatment to the point that injecting DEF into the exhaust stream will no longer be doing its job. At a certain temp the DEF will not react with the SCR to reduce NOX. Not only that but since the engine is not burning fuel no NOX is created. At that point you cannot reduce the level of NOX exiting the engine with DEF if no NOX is produced.

 

There I was, in the middle of no where in the front range of the Rockies ....had to jake in reverse off a grade on a goat trail @ GVW 210,000 cause I powered out. A little stressful when the drivers side was a 200 ft cliff. Remind me why I wanted to drive truck....

 

ImI not taking about DPF. It's take same grind on everything else as pushing hurd

 

It’s fascinating how the company thinks that their “experts” have more knowledge of how to make a manufacturer’s engine operate more efficiently than the engineers who designed it.
These engine companies spend millions of dollars working out the best settings for fuel mileage, power, and durability.
But the co lunkheads know more...

 

Not sure what you are meaning there, but the DPF is not having to work either with it as no combustion is taking place during an engine braking event especially a long downhill section. No combustion, no need for aftertreatment as there are no emissions being produced.

DPF = soot reduction
DEF and SCR = nox reduction

 

Unless you're one of them with the 8 inch exhaust and no mufflers. I wouldn't worry about the no jake signs. I think those signs are more for the screamers.