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jake brake


M W's Avatar
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12-09-03, 09:55 PM   #1  
jake brake

Ever heard of a Jake brake on a gas engine? Looking at a 36' RV with a 454 with a Jake...? Possible, impossible?

 
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mike from nj's Avatar
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12-09-03, 10:30 PM   #2  
mike from nj
if there was one, it would be here:
http://www.bankspower.com/banks_brake_home.cfm

they list diesels only

thinking theory of gas vs. diesel engines, it might not be possible. you could certainly make one, but i think all the pressure backing up through the cylinders and then shooting out the intake valve into the intake manifold would certainly screw up the carbureter or at least the MAP sensor signal.


just my opinion


i found this in my 'motorhome' magazine, a lot of good reading and tech articles in there. maybe your library has some old copies of this. another good one, is 'highways', but you need to join the 'good sam club' to get this one. http://www.goodsamclub.com

 
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12-10-03, 04:49 AM   #3  
jakes...

a jake brake is a device that will give you compression braking in a diesel engine...in a diesel, you throttle fuel....in a gas engine, you throttle air...it's the resistance of the air trying to get past the closed throttle that gives you engine braking in a gas engine...ergo...you already have a jake brake, so to speak.

 
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12-10-03, 11:42 PM   #4  
mike from nj
ergo...you already have a jake brake, so to speak




car guy, in theory---yes, in function----no

lifting off the throttle, especially in a gm application where you're driving through a sprag clutch, unless you manually downshift, you'll just coast until gravity takes over.

i spent a week in europe, and i watched the bus driver pull the 'retarder' (as he called it) lever on the steering column, he could nearly stop the bus cold on a twisty downhill without touching the brakes. there were a few times where we slid forward in our seats from the exhaust brake being applied. after talking to him a while, i found out that they are mandatory on all busses in that country.

good thing!

 
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12-11-03, 04:49 AM   #5  
mike...

...for the layperson i was just giving a basic understanding of the resistance of the air used for the purpose of compression braking. you are absolutely correct about overrun clutches in modern automatics being used to eliminate that drag, thereby increasing fuel mileage slightly. i'm thinking that most owner's manuals specify using manual 3rd to get compression braking in overdrive equipped vehicles...frankly...on a heavy RV, you don't get much compression braking anyway...so if he wants a jake brake, he ought to shop for a diesel pusher...hell...they do a better job on a class A...period! thanks for your input...hope your day is a good one

 
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12-11-03, 10:24 PM   #6  
mike from nj
agreed


hope i wasn't coming off as confrontational




i'm not

 
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