Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 02-17-2013, 10:54 AM   #1
Member
 
elang's Avatar
 
Join Date: Jul 2012
Location: Phoenix, AZ
Posts: 87
exhaust brake versus compression brake

Hi kind of new to dp, got a 36t 99 discovery and i've read about the braking system and I liked to know what is the difference between the two, tkx for all info, also I don't drive with compression brake use it only going downhills.
__________________

__________________
elang is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 02-17-2013, 11:24 AM   #2
Senior Member
 
dons2346's Avatar
 
Country Coach Owners Club
Join Date: Dec 2010
Posts: 4,487
Compression Brake Compression release engine brake - Wikipedia, the free encyclopedia

Exhaust Brake Exhaust brake - Wikipedia, the free encyclopedia
__________________

__________________
dons2346 is offline   Reply With Quote
Old 02-17-2013, 11:38 AM   #3
Moderator Emeritus
 
RustyJC's Avatar


 
Texas Boomers Club
Join Date: Jul 2000
Location: Cypress, Texas USA
Posts: 8,854
If you have a choice between the two, the compression brake is more effective due to its inherent design advantages over the exhaust brake. The exhaust brake is generally used on smaller diesel engines that don't have the option of using a compression brake - the B-series Cummins, for instance.

Rusty
__________________
2016 Ram Longhorn 3500 Dually 4x4 CCLB, 385/900 Cummins, Aisin AS69RC, 4.10
2014.5 DRV Mobile Suites 38RSSA #6972
Come join us on a TEXAS BOOMERS rally!
RustyJC is offline   Reply With Quote
Old 02-17-2013, 12:53 PM   #4
Senior Member
 
Country Coach Owners Club
Join Date: Feb 2012
Location: Phoenix AZ
Posts: 240
The engine brake usually called a "Jake" brake is internal to the engine and operates using your engine oil supplyto divert oil to small cylinders within the Jake. When activated the solenoids will hold the exhaust valves open and use the drag of the engine to slow down the vehicle using what is called parasitic drag. The exhaust brake is a simple device that restricts the flow of exhaust gasses coming out of the engine thereby slowing down the engine. The exhaust brake is not inside the engine. The Jake is much more effective and if you are near an 18 wheeler coming down a mountain you will hear a distinctive whap, whap, whap noise coming from the exaust as compared to the exhaust brake which is pretty quiet.

My guess is that nearly all class 8 trucks use a Jake to control downhill speed with an 80,000 pound gross weight. An exhaust brake would be almost useless in this case in my opinion.
__________________
chuydog is offline   Reply With Quote
Old 02-17-2013, 07:48 PM   #5
Senior Member
 
Tony Lee's Avatar
 
Join Date: Sep 2012
Location: Peru heading for Brasilia, Brazil
Posts: 2,118
Quote:
The engine brake usually called a "Jake" brake is internal to the engine and operates using your engine oil supplyto divert oil to small cylinders within the Jake. When activated the solenoids will hold the exhaust valves open and use the drag of the engine to slow down the vehicle using what is called parasitic drag.
My interpretation is a little different. The mechanism actually leaves the exhaust valves closed as normal during the compression cycle until the piston reaches top dead centre and then allows them to open. This turns the engine into an air compressor and the compressed air blasts out (hopefully through the muffler) making the distinctive noise. This compressing the air requires energy and this is what provides the retarding force. Without the mechanism the compressed air would drive the piston down giving zero net braking.

Without some sort of auxiliary braking, a normal diesel engine is in itself a much poorer retarder under zero throttle than a normal gasoline engine. This is because the diesel engine has close to zero losses due to the air movement through the engine and the main retardation comes from friction, water pump, fan, and alternator. A gas engine has a highly restricted air intake under zero throttle and this acts in exactly the same way as the external exhaust brake often fitted to diesel engines as a cheaper and less effective option to the internal engine brake.
__________________
Tony Lee - International Grey Nomad. Picasa Album - Travel Map
RVs. USA - Airstream Cutter; in Australia - MC8 40' DIY Coach conversion & OKA 4x4 MH; in Germany - Hobby Class C; in S America - F350 with 2500 10.6 Bigfoot camper
Tony Lee is online now   Reply With Quote
Old 02-17-2013, 08:49 PM   #6
Senior Member
 
Country Coach Owners Club
Join Date: Feb 2012
Location: Phoenix AZ
Posts: 240
Tony, I think you and I are basically singing out of the same hymn book in trying to describe what a Jake (Jacobs) engine brake does.

Tom
__________________
chuydog is offline   Reply With Quote
Old 02-18-2013, 06:11 PM   #7
Member
 
elang's Avatar
 
Join Date: Jul 2012
Location: Phoenix, AZ
Posts: 87
thank you all for the info very informative
__________________

__________________
elang is offline   Reply With Quote
Reply

Tags
brake



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 09:10 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.