Will such devices hurt my 617? I drove a cummins thru town the other day that was equipped with an exhaust brake, and COOL was all I had to say.

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RIP: 80 300SD
RIP: 79 450SEL
2002 E430 4matic (212,000km)
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Exhaust brakes are simple devices, but IMO don't create much braking, I've been very disappointed in the amount of braking. A simple butterfly in the exhaust (with a relief valve in the butterfly typically) flow, will increase exhaust pressures.

The original "Jake Brake" on the other hand, drops exhaust valves open at TDC and creates tremendous pumping losses equal to the max. HP output of the engine, a real brake (developed when Mr. Cummins lost brakes in Wolf Creek Pass, wanted to make his engines safer. He went to Mr Jacobs, of Jacobs Chuck fame for development/production, a star was born).

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Gone to the dark side

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AFAIK the 617 can't be equipped with a 'jake brake'
Also, wouldn't this put alot of stain on the flex discs? That Cummins probably has steel u-joints

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

Potential problems:

If you mount the butterfly on the intake side, if it's a turbo engine, some turbo's aren't designed for a vacuum and you can suck oil right through the labrinth seals and into the engine (bad). You may be able to get by with a post-turbo valve.

Exhaust mounted valves should work just as they do in Cummins, etc... The flex disks should have no trouble with the negative torque as it will probably never exceed the value of the positive torque.

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-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

Seems like an exhaust brake on a car is a waste of money unless your towing a house trailer

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

You can not use a post turbo gate valve as an engine brake, it will have the exact same effect as a plugged trap oxidizer.

Please read through the following threads for more data...

Trap Oxidizer, LINKS thread
http://www.peachparts.com/shopforum/showthread.php?t=229522




Have a great day.

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1985 300SD
1983 300D
1984 190D
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I've got an electric retarder on my Bluebird Wanderlodge bus and an exhaust brake on my Fuso FG. The exhaust brake is way less effective than the retarder, but I was surprised at how effective the exhaust brake was. I could come down I-70 from the Eishenhower tunnel without using the brakes by just deploying the exhaust brake. This was lightly loaded.
It sure looks to me like the exhaust brake is a butterfly valve post-turbo.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Exactly. The reason they are installed on 3/4 and 1 ton trucks is to aid in braking when towing a load. Exhust backpressure must be controlled on these exhaust brakes to prevent blowing out exhaust gaskets and seals. The older ford powerstroke diesels (94-97) used an exhaust backpressure valve to help warm up the engine in cold ambient temps. When I had my 95 F-250 PSD I remember it would frequently break the rear end loose when the EBPV would kick in and the roads were snowy (2wd). I ended up just disconnecting it because it was extremely annoying.

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'83 300D 198,000mi Howard
'03 Saturn Vue CVT 75,000mi(wifeys)

Good point, but not applicable.

The butterfly valve is always post-turbo in an exhaust brake turbodiesel. It will not create heat problems, because it is during the off-throttle phase where there is little heat generated by the engine. When the pedal is pressed, the exhaust brake opens (almost instantly) before any significant heat is generated. Further, the butterfly valves / exhaust brakes I've looked at always have a relief valve and some method for allowing some air to pass to prevent heat-soak at the turbo.

Kerry: The Jacobs/Telma retarder on the FCs is an excellent brake. Better than the later transmission retarder on the ZF transmissions in many ways, be sure you grease it properly with high-temp grease though!

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Gone to the dark side

- Jeff

Hook up a valve to switch over to cold, unfiltered WVO when you want to slow down Just kidding...

__________________
$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

I learned that lesson quickly when I used it prior to reading the manual on the steep road into Palo Duro Canyon. It melted the grease pronto.

The original owner of my 82 Bird paid $5k to have it installed aftermarket. Expensive braking.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Yeah, cheaper than trading it for an '83 though.

__________________

Gone to the dark side

- Jeff

Hadn't thought of it that way. He also paid $5k to have an aftermarket turbo installed. That's about as a close as a person could get to a complete waste of money without actually being a complete waste of money. It does give it a little more air at altitude.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

A turbo on a 3208na is useful at altitude, I agree. To use much boost without the turbo engine's upgrades might be foolish though. The early '83s only got 15hp from the turbo, and that at a cost of 200rpm off the top I'm not sure it was worth it. Now the 3208ATAAC with the overdrive ZF on the other hand, ... THAT was an upgrade.

__________________

Gone to the dark side

- Jeff