Water Injection

[stevetubbyturbo]

Ive heard things of WI on a diesel and surposedly it works really well.

Ok it dont raise the BHP but its ment to make it a bit more responsive and the main reason really reduce the black smoke most diesels pump out and my Surf is a real black smoker as it has a EGR valve.

Ok i could disconnet the EGR but as the 2.4 Surfs can suffer with cracked cylinder head due to overheating and uneven heating and disconnecting the EGR could cause this so i think i'll leave it be but WI is meant to reduce black smoke.

Any thoughts from anyone would be greatfully recieved.

Cheers

Steve

[Cubic Incubi]

WI will make fuel charge denser. deters pre ignition on pertol cars.

however your engine loves pre ignition, in fact thats how it makes its combustion.

I don't know enough about diesel performance. sorry.

my dad's got a surf aswell.

you'v got EGR becuase thats what jap cars have.

it can run without it afaik.

[jaxx]

i thought EGR valves were to help with emission control

[stevetubbyturbo]

i thought EGR valves were to help with emission control

←

They are but its to reduce NOx emissons as it stops the exhaust temp raiseing by allowing exhaust gas back into the system but this cause's very heavy black smoke at power.

you'v got EGR becuase thats what jap cars have.

it can run without it afaik.

the only problem with disconnecting it is it raises running temps and can cause uneven heating and hot spots and crack the clyinder head but a lot of people will debate this.

[daktari]

Steve - Have you looked into this..... EBAY

[stevetubbyturbo]

yeah its the ball bearing mod which just stops the EGR valve working you can get the same effect with a cable tie but it again shuts the EGR valve down which im trying to keep in operation.

But thanks anyway

[daktari]

Thought it was too good to be true. 5 quid for a ball bearing eh????/ I can see a cash making opportunity here.... Just got to break up some more wheel bearings.

[nrgizerbunny]

EGR exhaust gas recirculation can be used on a diesel car because diesels always run lean. ie excess oxygen in the combustion charge. you can therefore recirculate the exhaust gas in the knowledge that there is still plenty of oxygen left in it.

and yes it is designed to prevent NOx.

petrols, ideally run at stoichiometric which is where there is just the right amount of oxygen to combust all of fuel and produce CO2 and water - although this rarely happens as you get uneven combustion which leads to carbon monoxide and other nasties.

any way enough of my aside. Water injection will make your performance improve but you have to get it right.

the efficiency of ANY cycle, be it Otto (petrol), Diesel (diesel), Brayton (Gas Turbine) is basically the difference between the temperature at the inlet and the combustion temperature. If you can make the inlet temperature lower then you will get more power. Hence WI will work.

now here's the problems:

1. Rolls-Royce olympus jet engines used water injection on high hot air fields to increase power output, problem was the water corroded some of the engine parts. so durability may be an issue

2. You have to make sure that the water evaporates into the air completely- so you need a very fine mist almost.

3. As the engine RPM increases, the volume of air it inhales over a given time increases, so you need to spray more water in to get the same effect. so you need some kind of controller.

4. if you spray water into the air then invariably you have to slow that air down, this will cause a pressure drop which will rob you of power.

i think thats about it.

hope this helps.

[Mick24]

If you are sure the Pump Timing is correct and the Injectors are ok and not "dribbling" :-

You could try adjusting the Full Load Injection Volume on the pump yourself. It's a fine line between excessive black smoke and poor performance on most Toyota Diesels,but not impossible to get a happy medium.

The adjustment screw is normally M6 hex headed,so you can "paint" one of the flats of the screw so you know how far you have moved it from the Factory settings.

Turn the screw Anticlockwise to reduce the Injection Volume - 1/2 a turn is approx. 4cc of fuel. You will have to adjust the idle speed as you reduce the fuel.

Once you have a "happy medium",replace the lockwire and lead seal(fishing weight).

[earpl]

we use water injection in our kiln/ pre-heater system at work, all this does is reduce nox levels. just seams strange when you first learn about it. "trying to get kilns hot to about 1600*c, so lets spray water in it :P"