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I'm just thinking about the pressures involved with an exhaust brake fitted onto a TDCi engine potentially causing issues with the tappets.
Not an issue on the earlier straight mechanically operated land rover diesels.
Mike.
Edit: Added article link below.
View topic - Exhaust Brakes for 4x4s | Australian 4WD Action
Interesting comment in the last post of this link.
More of an advertorial but does give an explanation (and the difference between exhaust & Jake brake).
Banks Power | How An Exhaust Brake Works
Colin
I bought Isuzu EB,s from the wreckers and put one on both my Forward Controls. One has the 4BD1 and the other the 6.2 Chev.
They have an electric solenoid so I run them from the brake light feed via a manual switch on the dash.
Its normally off and only switched on when needed for long down hill runs etc. Just a tap on the pedal then works it.
The only downside is sometimes the butterfly seizes due to not enough use.
I really need to switch it on and use it once a week or so.
K
I'm inclined to agree that you're correct in this thinking!!!Quote:
Originally Posted by 90@
The pressures induced are unlikely to be in the design of the engine.
For the price, a set of high quality ceramic brake pads and quality rotors would suit those few times its actually needed...
Drop a gear (or 3) and the Tdci will happily rev (yes it loves to rev) and only takes a few brake dabs to keep in check...
Thanks for the info guys. As I suspected, not an easy fit. I will review the info that has been posted and speak to my mechanic and go from there.
The ceramic pads and better rotors will also be investigated.
Just the comfort and peace of mind to come down a steep incline letting the donk do most of the work would be good.
My old 200 Tdi was equally bad at engine braking and going down a gear did little to reduce speed but plenty to increase revs.
More food for thought
And not forgetting high temp brake fluid :). PatQuote:
Originally Posted by Tombie
Yes,Quote:
Originally Posted by Tombie
The basic design of the head is not conducive for fitting an exhaust brake.
If it was an earlier land rover diesel head design, it would be easier to guard against issues by utilising stronger valve springs (maybe the best option for a design with an exhaust brake would be desmodromic operation), however with the engineering design and construction used in the TDCi engine variations and the hydraulics (tappets/lifters) incorporated into the design of the valve train and the low back pressures that these engines run, it is not an optimal design for an exhaust brake operation and it brings a few issues into the equation that have the potential to be very expensive to repair if/when something goes wrong.
Anyways,
Another link here (I suggest reading the answer to FAQ4)....
Jacobs Vehicle Systems | FAQs
Regards,
Mike.
Addition to my post above....
I am aware of the differences between Clessie Cummins designs as utilised by Jacobs, and the butterfly valve systems that Chenz is probably thinking of using.
Some of the same issues with valve train actuation due to the pressures applied by exhaust retardation apply to both designs.
Mike.
THAT'S the kind of tech info I was looking for!Quote:
Originally Posted by gromit
Some interesting considerations.
I'm wondering what the exhaust valve springs are rated at in the tdci? Valve spring pressure is usually measured in pounds. I'm guessing this could be converted to a PSI rating given the area on the back of the4 exhaust valve that the pressurized restricted exhaust acts on?
The problem isn't the valve spring pressure in the TDCi engines, the problem is with the design of the valve train bridge and it's components......Quote:
Originally Posted by Toxic_Avenger
More specifically the hydraulic tappets.
Exhaust brake trials have been done on TDCi engines, and successfully disintegrated them too....
Mike.