Thread: Exhaust Brake for 3.9 Isuzu County

if you want to heat the engine up faster you only have a handfull of options...

1. rev the nipples off of it as soon as it gets oil pressure
2. put a blind over the radiator grill to slow the airflow through the engine bay
3. remove the fan and fit thermos
4. install a preheater.

the only way an exhaust brake will lift the engine temperature is if its installed incorrectly and you can activate it with a higher fuel setting than idle... then you floor it get the thing reving and close off the brake.

but that will only have limited sucess as what will happen is the back pressure in the exhaust system will keep more and more exhaust in the combustion chamber and then you get less o2 for the next stroke.

the cheapest preheater Ive ever used was a simple indoor heater in the garage that I had mounted on a small frame that pointed it up towards the engine.Id park slide it up infront of the front diff and then drag the extention cord to the house... when I woke up in the morning if there was ice on the grass Id plug it in and by the time Id done breakfast, dishes, and all the other gumpf involved in getting ready to go the engine would be warm enough for an easy start and by the time i had it out of the garage , closed the door, driven down the driveway opend driven through and closed the main gate theres be heat coming out of the vents.

is your switch the one that u pull up and it stays on untill you push it back down? and do you rekon a 200tdi would handel a exhaust brake or would it affect the turbo ?

for more info on this, one of our LROC (syd) members has done this on a 3.9 isuzu. he's a member of aulro and geos by the name of mervyn.
PM him and ask

I dont have an exhaust brake...

But Id have it wired up so that it would be controled by 3 switches...

1. on the gear shift so that I could turn it on and off manually or have it set to auto
2. on the accelerator that would turn the thing off if the accelerator was depressed at all.
and
3. on the brake switch so that if the brakes were on and the gear shift switch was on auto then it would come on.

any turbo engine will deal with one but you have to watch the lag when you come up off of the brake and back onto the noise.

Originally Posted by Blknight.aus

if you want to heat the engine up faster you only have a handfull of options...

..........
2. put a blind over the radiator grill to slow the airflow through the engine bay
........

I have a set of strips of plastic, actually black damp course, cut to fit the vertical spaces in the grille between the pillars joining the louvres. They are held in place between the louvres of the grille and the chaff guard. Usually all except the middle space are blocked off throughout winter. This makes sure the heater (sort of) works before I get halfway into town (Depending which way I go I have 6km and five gates to the road or 18km and one gate, so the first bit of the trip doesn't help warming up).

I would also comment that the only thing I have had to do to the engine in 470,000km is to replace the thermostat twice. In both cases it was running the engine cooler than normal, and slowing the warmup. This engine has a lot of mass and a lot of oil and water to heat up (the main reason why it stands abuse a lot better than the Tdis or Td5) and needs all the help you can give it in winter.

John

Originally Posted by Blknight.aus

if you want to heat the engine up faster you only have a handfull of options...

1. rev the nipples off of it as soon as it gets oil pressure
2. put a blind over the radiator grill to slow the airflow through the engine bay
3. remove the fan and fit thermos
4. install a preheater.

The problem is the engine has no load, it idles at altitude in sub-zero (usually around 0 to -10C) conditions which are such that it never reaches warm. It then gets driven down a long hill (like 10km long, 1000m-1400m vertical) using engine braking. Again no engine load to warm it up.

1 won't work as higher revs mean the engine just pulls through more sub-zero air. I need load to warm up the engine and the exhaust brake will be used to provide it. Isuzu use an exhaust warm up flap in their JDM Mu's.
2 won't help because the thermostat stays closed and the radiator does next to nothing.
3 I have electric fans.
4 It's not that cold and there is nowhere to plug an electric one in up a skifield.

The exhaust brake is planned to increase engine load at idle and on the way down the hill.
The other option is an intake flap to restrict airflow, which increases EGT's and warms the engine up. My nissan diesel work car uses this method.

Originally Posted by Blknight.aus

but that will only have limited sucess as what will happen is the back pressure in the exhaust system will keep more and more exhaust in the combustion chamber and then you get less o2 for the next stroke.

Yes, that's the plan.

next alternative - keep the engine warm from the previous day. My Grandmother did this for years and years. Nose into an old matress and throw a couple of old horse rugs (or similar) over the bonnet when you are done for the day. Next morning there is still some warmth in the motor even in sub zero temps.

Originally Posted by Dougal

The problem is the engine has no load, it idles at altitude in sub-zero (usually around 0 to -10C) conditions which are such that it never reaches warm. It then gets driven down a long hill (like 10km long, 1000m-1400m vertical) using engine braking. Again no engine load to warm it up.

1 won't work as higher revs mean the engine just pulls through more sub-zero air. I need load to warm up the engine and the exhaust brake will be used to provide it. Isuzu use an exhaust warm up flap in their JDM Mu's.
2 won't help because the thermostat stays closed and the radiator does next to nothing.
3 I have electric fans.
4 It's not that cold and there is nowhere to plug an electric one in up a skifield.

The exhaust brake is planned to increase engine load at idle and on the way down the hill.
The other option is an intake flap to restrict airflow, which increases EGT's and warms the engine up. My nissan diesel work car uses this method.



Yes, that's the plan.

Im guessning then that your goingto set it up "incorrectly" so that you can activate the brake while you have the engine recieving above Idle fuel settings....