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05-28-2019, 08:16 PM
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#41
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Bus Crazy
Join Date: Oct 2017
Location: Virginia
Posts: 2,325
Year: 1971
Coachwork: Wayne
Chassis: International Loadstar 1700
Engine: 345 international V-8
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Charlie, thanks for posting the Telma videos, great info.
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05-28-2019, 10:03 PM
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#42
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Bus Nut
Join Date: Jul 2017
Location: Rapid City, SD
Posts: 993
Year: 2001
Coachwork: Blue Bird
Chassis: CS RE
Engine: ISC 8.3 L 260 hp
Rated Cap: 36
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The variable geometry turbo on the Cummins ISC can function as an exhaust brake. I have't figured out if it is enabled on mine or if I would need to add a switch and enable it in the ECM.
Ted
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05-29-2019, 07:17 PM
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#43
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Bus Nut
Join Date: Mar 2017
Location: Greenwood, Indiana
Posts: 670
Year: 1999
Coachwork: New Flyer
Chassis: D45HF "Viking"
Engine: 11.1L Detroit Diesel S60
Rated Cap: 51,600
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My Detroit S60 + ZF tranny has an interesting combo: the tranny has the hydraulic retarder, and the engine can "turn off" 2 or 4 of the cylinders. I'm guessing the engine "turning off" 2 or 4 of the cylinders is much like the noisy jake brake, but I haven't heard the engine even when braking like that....
Unfortunately I have yet to get it out on some decent grades.
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05-29-2019, 07:36 PM
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#44
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Bus Crazy
Join Date: Nov 2018
Location: south east BC, close to the Canadian/US border
Posts: 2,265
Year: 1975
Coachwork: Chevy
Chassis: 8 window
Engine: 454 LS7
Rated Cap: 24,500
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Quote:
Originally Posted by MarkyDee
My Detroit S60 + ZF tranny has an interesting combo: the tranny has the hydraulic retarder, and the engine can "turn off" 2 or 4 of the cylinders. I'm guessing the engine "turning off" 2 or 4 of the cylinders is much like the noisy jake brake, but I haven't heard the engine even when braking like that....
Unfortunately I have yet to get it out on some decent grades.
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I always thought the motors that were able to shut down some cylinders was a fuel saving feature
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05-29-2019, 07:48 PM
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#45
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Bus Nut
Join Date: Mar 2017
Location: Greenwood, Indiana
Posts: 670
Year: 1999
Coachwork: New Flyer
Chassis: D45HF "Viking"
Engine: 11.1L Detroit Diesel S60
Rated Cap: 51,600
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Quote:
Originally Posted by Sleddgracer
I always thought the motors that were able to shut down some cylinders was a fuel saving feature
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Maybe it is, I'm a complete neophyte at this.... Your guess is actually better than mine. But looking at the PLC logic, it seems the PLC requests cylinders to be shut off during braking. I'll look again just to be sure.
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05-29-2019, 07:54 PM
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#46
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Bus Crazy
Join Date: Nov 2018
Location: south east BC, close to the Canadian/US border
Posts: 2,265
Year: 1975
Coachwork: Chevy
Chassis: 8 window
Engine: 454 LS7
Rated Cap: 24,500
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Quote:
Originally Posted by MarkyDee
Maybe it is, I'm a complete neophyte at this.... Your guess is actually better than mine. But looking at the PLC logic, it seems the PLC requests cylinders to be shut off during braking. I'll look again just to be sure.
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that would make sense too - you don't need fuel sent to the cylinders during braking
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05-29-2019, 07:57 PM
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#47
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Bus Nut
Join Date: Mar 2017
Location: Greenwood, Indiana
Posts: 670
Year: 1999
Coachwork: New Flyer
Chassis: D45HF "Viking"
Engine: 11.1L Detroit Diesel S60
Rated Cap: 51,600
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Heh, I saw that logic in the PLC and I just thought "cool! I don't need no stinkin' jake!"
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06-01-2019, 08:36 PM
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#48
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Bus Nut
Join Date: May 2015
Posts: 271
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It’s simple- as a CDL driver you start down the hill in a gear lower than you climbed it in. Slow and steady. My transfer truck and trailer had a18 speed and Jake brakes. The 10 wheel with an automatic didn’t have engine braking- the automatic transmission was a huge mistake but that’s another discussion. When going downhill the automatic transmission “automatically shifted to the next higher gear because the computer just thought it was the thing to do... stickshifts won’t do that. So going slow and proper braking practices will keep you safe. I see folks driving those big ass motorhomes riding their brakes flying downhills. Zero training is unacceptable- killing people is inexcusable- take the run-away truck ramp and pay the fines. Cheers
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06-02-2019, 05:48 AM
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#49
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Bus Crazy
Join Date: Feb 2018
Location: Golden Valley AZ
Posts: 1,036
Year: 1993
Chassis: ThomasBuilt 30'
Engine: need someone to tell me
Rated Cap: me + 1
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Quote:
Originally Posted by turf
i have a locking transmission now and life is much easier as it helps control the downhill speed too.
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Will someone please clue me on what a locking transmission is? How do I find out if mine is one?
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06-02-2019, 09:17 AM
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#50
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Bus Crazy
Join Date: May 2016
Location: Georgia
Posts: 2,264
Year: 2001
Coachwork: Blue Bird
Chassis: IH
Engine: T444E
Rated Cap: 14
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Quote:
Originally Posted by kidharris
Will someone please clue me on what a locking transmission is? How do I find out if mine is one?
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Pretty much any transmission other than the AT545.
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06-02-2019, 09:21 AM
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#51
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Skoolie
Join Date: Mar 2018
Location: Fingerlakes region NY
Posts: 204
Year: 1999
Coachwork: AmTran/Wolfington
Chassis: 3800
Engine: International DT466E 190HP variant
Rated Cap: 72 pax 29500 GVWR
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Quote:
Originally Posted by MarkyDee
My Detroit S60 + ZF tranny has an interesting combo: the tranny has the hydraulic retarder, and the engine can "turn off" 2 or 4 of the cylinders. I'm guessing the engine "turning off" 2 or 4 of the cylinders is much like the noisy jake brake, but I haven't heard the engine even when braking like that....
Unfortunately I have yet to get it out on some decent grades.
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The Series 60 in my job’s FreightShakers has the same setup. It’s an engine brake with multiple options. You can have 2, 4, or all 6 cylinders working for engine braking. It’s just different levels. Our CAT C7s have a “Hi/Low” setting for the engine brake as well.
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06-02-2019, 09:53 AM
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#52
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Bus Crazy
Join Date: Nov 2018
Location: south east BC, close to the Canadian/US border
Posts: 2,265
Year: 1975
Coachwork: Chevy
Chassis: 8 window
Engine: 454 LS7
Rated Cap: 24,500
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learn something new every day
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06-02-2019, 12:19 PM
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#53
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Bus Nut
Join Date: May 2015
Posts: 271
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Not all newer transmissions have “locking” capabilities.
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06-02-2019, 06:44 PM
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#54
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Bus Geek
Join Date: Sep 2014
Location: Eustis FLORIDA
Posts: 23,764
Year: 1999
Coachwork: Thomas
Chassis: Freighliner FS65
Engine: Cat 3126
Rated Cap: 15
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Quote:
Originally Posted by Dirtdoctor
Not all newer transmissions have “locking” capabilities.
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Which modern school bus transmissions don't have locking torque converters?
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06-02-2019, 07:48 PM
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#55
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Bus Crazy
Join Date: Feb 2015
Location: Cincinnati, Ohio
Posts: 1,001
Year: 2000
Coachwork: Blue Bird
Chassis: International
Engine: TE 444
Rated Cap: 12
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when I was driving trucks in the 80's and 90's pretty much only owner operators had jakes, I drove one truck that had a blue ox exhaust brake, which is just on-off and work ok but not as good as a jake brake
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06-02-2019, 07:54 PM
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#56
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Bus Crazy
Join Date: Oct 2017
Location: E Central Tejas
Posts: 2,094
Year: 1998
Coachwork: Thomas
Chassis: IH 3800, 8 window
Engine: T444E w/ Spicer 5-speed MT
Rated Cap: I prefer broad-brims hats
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Is it worth looking to see if a T444E could be retrofitted with one of those beauts?
Quote:
Originally Posted by Kubla
when I was driving trucks in the 80's and 90's pretty much only owner operators had jakes, I drove one truck that had a blue ox exhaust brake, which is just on-off and work ok but not as good as a jake brake
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__________________
Those who say that it cannot be done should not interrupt the people doing it.
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06-02-2019, 08:44 PM
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#57
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Bus Geek
Join Date: Apr 2012
Location: So Cal
Posts: 3,231
Year: 1935
Coachwork: Superior
Chassis: Chevy
Engine: 317 ci/tid / Isuzu
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My Isuzu TD (in my Skoolie) has an exhaust brake controlled by the computer (manual switch as well). All it is is a block in the exhaust pipe sort of like the slice valve in a black tank drain controlled by vacuum. Short of the computer control, it would be easy to stick one of these in any vehicle. My exhaust brake opens at 30 mph--I suppose this keeps the engine from dying. This takes me back to when I was a kid and stuffed potatoes in unsuspecting motorist's tail pipes--too much fun!
Jack
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06-03-2019, 07:50 AM
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#58
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Bus Crazy
Join Date: Nov 2011
Location: Sault Ste. Marie, Ontario
Posts: 1,793
Year: 1997
Coachwork: Thomas
Chassis: B3800 Short bus
Engine: T444E
Rated Cap: 36
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The T444e has a butterfly valve (Exhaust Back Pressure Valve, EBPV) just after the turbo that is used to create back pressure to aid engine warm-up in cold temperatures. I've heard of people adding a manual switch to the valve for use as an exhaust brake.
https://www.ford-trucks.com/forums/1...ine-brake.html
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06-03-2019, 08:52 AM
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#59
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Bus Crazy
Join Date: Oct 2017
Location: E Central Tejas
Posts: 2,094
Year: 1998
Coachwork: Thomas
Chassis: IH 3800, 8 window
Engine: T444E w/ Spicer 5-speed MT
Rated Cap: I prefer broad-brims hats
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That is just TOO freakin' cool!
Quote:
Originally Posted by jazty
The T444e has a butterfly valve (Exhaust Back Pressure Valve, EBPV) just after the turbo that is used to create back pressure to aid engine warm-up in cold temperatures. I've heard of people adding a manual switch to the valve for use as an exhaust brake.
https://www.ford-trucks.com/forums/1...ine-brake.html
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I have SO gots to git me one! (Mountains figure in my future)
Thanx for the link,
Bookmarked!!!
__________________
Those who say that it cannot be done should not interrupt the people doing it.
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06-03-2019, 10:54 AM
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#60
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Bus Geek
Join Date: May 2014
Location: West Ohio
Posts: 3,709
Year: 1984
Coachwork: Bluebird
Chassis: International 1753
Engine: 6.9 International
Rated Cap: 65
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Well, although many have done it, Ford and Navistar are both against it. Because of the hydraulic lifters used in the engine, using the ebpv as a brake in certain circumstances can cause the exhaust valves to hang open and hit the pistons.
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