Outer Limits 4x4 Board

Got a mate askin bout whether its possible or not and how to go about getting a setup for the cruiser.

Its just a 2.5" zorst has anyone done it or know something bout it?

Speaking uneducatedly i would say no to jacobs, but im sure we could find a zorst valve brake?

Cheers

exaust brake is possible on a 1hz or 1hd. In fact coaster buses come with them from the factory.

I believe in most cases petrol engines aren't strong enough for an exhaust brake.

jake brake is out of the question unless you want to manufacture a completely custom head for it!

another thing to consider is wether or not the valves will burn out holding the extra heat/exhaust back.

maybe not as simple as bolting an exhaust brake set up on it. You will have to run a bit of electrics to control the pedals so its not always on when you use the clutch, accel, change gears, etc.

Then there is also the factor as to how well it will actually perform V's $$ cost. there arent many exhaust brakes that are half decent in small trucks. If you thinking of using it for towing,etc. Just get elec brakes on the trailer.

I hope i am wrong, i'd love to have one on my patrol, esp with a free flow exhaust.

http://en.wikipedia.org/wiki/Jake_brake is why one on a cruiser may prove problematic

but you may be able to make one of these work on it with a bit of a think

http://www.jakebrake.com/technology/exhaust.php

either that or one off a small bus or truck using the same engine or similar size engine

As Pongo said, the biggest problem is the heat it will retain, and for not a lot of gain.

i put an air operated exhaust brake on 2 diesel engined 4wd's, a Mercedes benz Gaelanden Wagen and a 47 series land cruiser.

The brake was only effective at very low speed, hence low range, where it made a significant difference to forward speed. I would say it slowed the venicle down 100% if applied in first low range and held it at that speed. Trying to use it at say normal 60klm/hr and above speed to slow the vehicle down was hopeless. I would say the effective upper speed limit was 15 klm/hr.

I first purchased a unit from the wreckers, then ended up building a couple of units - all 'mechanically possible' - but only of real benefit in first or second low range.

The jakes brake is a totally different system and yes, it slows big masses down, but a simple butterfly valve with a 3mm hole for pressure relief - not worth the effort. I ended up ripping mine off. Remember. you are trying to slow a mass down with a compressible medium, and it is not very effective.

I might have a unit under the bench you can have to play around with - let me know, happy to donate it.

if he does a lot of towing it could be worht the effort. I dont see any problem, as said coasters and similar sized light trucks run them with no problem.

PBBIZ2 wrote:i put an air operated exhaust brake on 2 diesel engined 4wd's, a Mercedes benz Gaelanden Wagen and a 47 series land cruiser.

The brake was only effective at very low speed, hence low range, where it made a significant difference to forward speed. I would say it slowed the venicle down 100% if applied in first low range and held it at that speed. Trying to use it at say normal 60klm/hr and above speed to slow the vehicle down was hopeless. I would say the effective upper speed limit was 15 klm/hr.

I first purchased a unit from the wreckers, then ended up building a couple of units - all 'mechanically possible' - but only of real benefit in first or second low range.

The jakes brake is a totally different system and yes, it slows big masses down, but a simple butterfly valve with a 3mm hole for pressure relief - not worth the effort. I ended up ripping mine off. Remember. you are trying to slow a mass down with a compressible medium, and it is not very effective.

I might have a unit under the bench you can have to play around with - let me know, happy to donate it.

I am used to engine brakes and retarders on larger trucks and busses so zaust brakes on small trucks have never excited me in terms of their effectivness, that said they do make a reasonable difference to the run off on hill, and have found they do allow you to grab the brake a little later on steeper hills and allow you to just foot off throttle on small declines where you would otherwise be feathering the brake.

They will not perfore miracles, but they certainly have a place imo, although I am not sure I would be going to any kind of trouble to retrofit to a 4wd, but otherwise happy to use on fitted on a small truck in cases where I am unfortunate enough to be driving one

Imo a waste of coin on a 4wd....they are designed for large capacity engines. You will get sfa benfit on a small engine going off the blokes before u that have had a crack at it

theres info of this on ih8mud.. think i've seen pics on there of a dude who did it to his 3b.. might find more info with a search on there.. I think it was in the diesel section..

There was a company in Aus making zorst brakes, I'll see if I can find them...

Yah...

http://www.gearingdynamics.com/exhaustbrake.htm

Holding heat in isn't a problem. Switch on the accelerator and clutch is all you need.
No accelerator means virtually no heat to hold in.

If you retrofit a brake off a bigger engine, then it will bypass too much gas to be useful. You'll need to find the hole the gas gets through and make it smaller.
Too small and you'll float the exhaust valves, but on a turbo engine you should be able to make around 30psi without trouble.

not too sure about the smaller engines.... but in the fire truck at 13 tonnes.... i can drive it down from barrington tops and not use the brakes once.... but the engine in the fire truck is 8 litre 6 cylinder

The exhaust brake on the 3.5t (4.2 turbo diesel) canter that i drive does a good job of holding speed down hills, never driven a truck with jake brake so can't compare but i do find on downhill runs in my ute i sometimes find myself going for the exhaust brake as a habit from the truck.
I was led to believe that when coasting diesels run little to no fuel thru the engine, i don't know if this is true but would mean that the only heat created would be the compression of the intake air

muckute wrote:The exhaust brake on the 3.5t (4.2 turbo diesel) canter that i drive does a good job of holding speed down hills, never driven a truck with jake brake so can't compare but i do find on downhill runs in my ute i sometimes find myself going for the exhaust brake as a habit from the truck.
I was led to believe that when coasting diesels run little to no fuel thru the engine, i don't know if this is true but would mean that the only heat created would be the compression of the intake air

With no throttle input, the injectors/pump are effectively at idle so yep, very little fuel going in.

The gearing dynamics one as suggested was what i remembered, hdj105 also from memory used to have an exhaust brake fitted to his 1hdt from a coaster/dyna truck.

shame you cant have exhaust brakes on a petrol. i would love to herd the noise on my zook when slowing down

but guys far as im concerned your all missing the point the NOISE hahah it would be great but as far as actually doin it, way to much effort....

tommy182 wrote:but guys far as im concerned your all missing the point the NOISE hahah it would be great but as far as actually doin it, way to much effort....

You wont get the noise from a simple butterfly valve i the exhaust.
The noise you hear from trucks is the jake brake, as pointed out is very different.

Hmmm food for thought, cheers people, he has decided to leave it be..