Diesel engine braking idea

[Hemi Joel]

There lot's of smart people here, so I thought I'd bounce this off you all: I'd like to get some engine braking capability into my Cummins powered 93 Dodge one ton. Sometimes I find myself driving in the mountains with a heavy camper and a big trailer, and it is real hard on the brakes. (and the nerves) Exhaust brakes are available for diesels to help get down long steep grades safely without cooking the brakes. They work by choking off the exhaust flow, turning the engine into an air compressor. But they are expensive and I have heard that they can be trouble prone due to carbon build up.
Gas engines have decent engine braking, just by closing the throttle valve, cutting off the air flow into the engine, turning it into a vacuum pump.
So how about installing a big throttle valve on a diesel on the intake manifold inlet for use as an engine brake? Is there any reason that wouldn't work? It seems that it would be cheap and easy to make, and would not carbon up.
Joel

[TheSilverBuick]

What happens to diesel engines when a restriction like that is put in place and forgotten to be opened before throttle is applied? Run rich/roll coal? Nothing significant? Are the rings okay with vacuum? Valve stem seals for that matter?

[Hemi Joel]

What happens to diesel engines when a restriction like that is put in place and forgotten to be opened before throttle is applied? Run rich/roll coal? Nothing significant? Are the rings okay with vacuum? Valve stem seals for that matter?

Or how about intake valve springs?

[DanStokes]

Not sure Joel but my '83 240D (the donor car for the manual trans) had an inlet restrictor (throttle plate) in it as a factory piece. I'm not quite sure what it's function was but we did some experiments at EPA on an earlier M-B Diesel and found out that restricting the inlet air on deceleration reduced PM (particulate matter) so that may have been the function of the one on the 240D.

On the 240D the throttle plate was actuated by the accelerator pedal - accelerator up, throttle plate closed. I'm not sure if it moved proportionally to the pedal position of if it was all on or all off.

If you could dig up a little info on the Benz setup you might turn up some useful data.

Dan

[Hemi Joel]

Dan, that's good info and very helpful. Thanks!

[milner351]

Joel - the 7.3 powerstrokes came from the factory with an exhaust back pressure valve or "warm up valve" integrated into the turbo assembly,
Lots of guys have removed them, other guys have put them on a push / pull cable to use them as a "jake brake"

I'm not sure what the adantage / disadvantages are of restricting the intake to the engine or the exhaust out of it, I would think either one would accomplish your objective.

if you find a stock 7.3 turbo pedestal - you'd have a good tough valve about the right size to experiment with - after some cutting you could mount it just about any way you wanted.

Here's a crude video of a guy pulling one apart on a bench:

https://www.youtube.com/watch?v=8UdJAgbcq8Q

there's other videos out there on how guys tuned them into exhaust brakes

[Hemi Joel]

Thanks for the info. I see on ebay, there are blowoff valves designed for blow thru carbureted turbo setups for less than $50. That would protect the turbo when the valve shuts. Then I could probably find the throttle body that I could adapt to the intake manifold, and run a rod or a cable into the cab to actuate it.

http://www.ebay.com/itm/190587735115?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

http://www.ebay.com/itm/111018528101?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

So many projects, so little time....