Exhaust Brake on a petrol engine

[cac]

Guys...

was reading an article a few years back on a company that could fit up an exhaust brake to most diesel 4WD engines...but there didn't seem to be an option for petrol owners....

as my zook is a petrol auto, i'm interested in what options i have for improving its engine braking (crawler gears an obvious one - though off topic in this section :))...and wondered whether or not an exhaust brake could be fitted to a petrol engine, would it actually give you a reasonable increase in engine braking like on a diesel, and is it going to be a reasonable cost option....

any thoughts on this??

cheers

cac

[Jarrod.]

i had similar thoughts after goin out on the weekend. was thinking about exhaust brake for my mk patrol petrol. but have no idea about them on petrols

[Marc 1]

I'm very much out of my depth here, but as the exhaust brake relies on compression, and petrols have compression ratios around half that of diesels, you'd probably only get half the result. Also diesels are built much stronger - you may risk damaging a petrol trying this.

[MUDRATGQ]

It would more than likely stall the engine or cause a build of unburnt fuel in the exhaust wich when ya get on the load peddal again ignite an blow the backside out of the exhaust system the same way it dose if when driveing an turn the key off for a second or 2 an then turn the key when i an a few mate's were younger we use to do that an you would get a loud gunshot like bang come out of the exhaust system an if ya turned the engine off for to long then hit the key the explosion was enough to blow the exhaust system cleen apart so im not to sure about the exhaust brake i have never headr of one being fitted to a petrol

[SAT44N]

It would stall a petrol. Besides a petrol doesnt have enough comp for any worthwhile gains.

[cac]

ok thx guys...looks like that may not be an option then....

[THE RIG]

does anyone have any information about fitting this kinda setup onto a diesel? is there a kit out there,just curious to how it all works is all...

[tasmq]

used to be kits around, try googling it

[cac]

the kit i heard of was from a company i think based in cairns

you could also look round a light truck wreckers...and see if a smallish truck has one fitted...some of the trucks you can drive on a car license i know do...as do a lot of coaster buses....

[THE RIG]

cheers guys

[ol blu 40]

you could also look round a light truck wreckers...and see if a smallish truck has one fitted...some of the trucks you can drive on a car license i know do...as do a lot of coaster buses....

No doubt you'd find one small enough, little Jap and Euro trucks all have 'em, but not as easy as it sounds. Depending on your engine pipe, you may have to cut and fit flanges to sandwich the butterfly valve in, and if you get the switchgear and solenoid off a donor truck it'd almost certainly be 24V. You should also be fitting the two switches for your clutch and accellerator cut-out, etc... (used to play with these things all the time!)

Not impossible by all means, just time consuming. Alternatively, a mob in Cairns called E.B.S. engineering used to do 'em for around 1200 bucks, maybe look 'em up and give 'em a call...?

Hope this helps,

Cheers, Matt

[bainsybainsy]

iv never seen an exhaust brake on a petrol engine before. petrols have alot less compression and would probably stall once the butterfly is closed. id say it wouldnt be very good for a lightly built petrol engine.

if you go ahead with it, you would have to work out a way to close your butterfly, trucks use an air cylinder to close it thru a solanoid, but there might be one that works with vacuum, im not sure.

you would have to set up a switch on your accelrator pedal to sence the engine is not trying to be driven, not unless you choose the exhaust brake to operate only under braking. if it was a manual you would have to put a switch on the clutch pedal aswell.

being an auto id go with the exhaust brake only come on during braking, or ull find ull be stalling it all the time!:thumb:

[eldo]

my bro works for toyota and he tells me that the toyota dyna uses the same engine as my 2003 sr5 hilux, the dyna has an exhaust brake. he is looking into it for me as i reckon it would be great for where i live as i am up and down the escarpment all the time, not to mention the savings on brake pads etc

[bainsybainsy]

is the dyna petrol or diesel? i just done an engine transplant on a 1973 dyna last week, had to take the pasanger door off and take it thru the cab, oh what fun! it was a petrol but no exhaust brake.

[D1cko]

is an exhaust brake the same as a Jake Brake?

[eldo]

the dyna is diesel.
yes jake brake is an exhaust brake

[bainsybainsy]

a jake brake or Jacobs brake is actually classed at an engine brake. it doesnt restrict exhaust gasses from exiting the engine to slow it down, it actually releases the compression of the engine at the end of the compression stroke, which causes a loud banging noise and slows the engine down. its pretty much releases all its energy before it gets put to use.

i love the sound of them. i ride the jakes all the way down crinigan road when i get the chance! haha no wonder they call me a bloody cowboy!:D

[ol blu 40]

a jake brake or Jacobs brake is actually classed at an engine brake. it doesnt restrict exhaust gasses from exiting the engine to slow it down, it actually releases the compression of the engine at the end of the compression stroke, which causes a loud banging noise and slows the engine down. its pretty much releases all its energy before it gets put to use.

What he said! Exhaust brake is (put simply) a butterfly valve which restricts exhaust gases from exiting the system, therefore increasing the effect of compresion braking. Jake brakes (and Macks Dynatard) use solenoids and oil pressure to open the exhaust valves in the head(s).

Cheers, Matt