so my new infatuation is a jake brake for my 98 24v my idea is to put a hall sensor and custom wheel at the crank and have it trigger a solenoid to open an exhaust valve, i have no clue as to how to keep it from injecting diesel to the one cylinder thou ....

 

Hmmm... Interesting I like it. Have you ever messed with one of the big Jacobson brake systems? just look at a QSX or older and see how they do it.

 

no, never even seen one in real life, ive never even pulled the rocker cover off either of my trucks,

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i really really need info to stop injection event thou

 

Pulling your foot off the pedal should reduce fuel injection to nothing until fuel is needed to keep low idle.

 

yeah thats what i was kinda thinking but im very leery of any diesel coming out thou, any thoughts on the safety of that, like its guaranteed theres gonna be no fuel that comes out what so ever? and i dont know very much about the vp's workings so i really need all the info i can get

 

you could put a shut off/bypass solenoid on that injection line. i would think you would need the bypass to save the vp.

wouldn't you need to hold closed an exhuast valve?

 

wouldn't you need to hold closed an exhuast valve?[/QUOTE]

No, you gotta keep an exhaust valve open. If you kept it closed the intake valve would keep opening and all of that air has got to go somewhere. It might bend something.

How are you going to do it on one cylinder? On the big rigs you select either the back 3, front 3, or all cylinders for the jake brake with a switch.

 

No, you gotta keep an exhaust valve open. If you kept it closed the intake valve would keep opening and all of that air has got to go somewhere. It might bend something.

How are you going to do it on one cylinder? On the big rigs you select either the back 3, front 3, or all cylinders for the jake brake with a switch.[/QUOTE]


Actually you choose between 1,2, or all 3 heads (on N14 and older), newer ones it's 2,4 or all 6 cylinders

I have actually been throwing this around for a while, there has to be an application that used a 24V head with jakes, I think I will call my contacts at Cummins in the morning, a head swap and such would be much easier than reverse engineering this system.

 

From what I know about Jake heads the exhaust valve opens on the compression stroke at TDC then closes before it travels downward on the power stroke. The loud cackle from the exhaust is from that cycle of open/close. that's done by the injector cam lobe the larger diesels have a third lobe on the cam. if you just hold the exhaust valve open then the engine will just free wheel and gain speed. You need the compression/vacume of the cylinder to slow the engine. So timing the open/close of the valve is the key to the whole thing.

 

to whom it may concern, z, the exhaust valve is opened kinda at the end of the compression stroke before firing, and yes on big rigs its selectable to how many cylinders u want, i think just one cylinder for my application(sound only) is plenty

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if i went with shut off and bypass, where would all that pressure return to?