Classic cars forum & vehicle restoration.

[xkjaguar]

water injection
two schools of thought on this:-

1. you inject a small amount of water into the induction manifold which has 2 effects, firstly it cools the air charge making the air denser, thus more air can be fitted into the cylinder and more fuel burnt---problem i can see here is does the extra amount of air compensate for the volume lost due to water vapour/steam?

2. air is approx 16% oxygen water approx 30% the theory is the extreme of temp/press flashes off the water so rapidly that the oxygen is released again allowing more fuel to be burnt---problem i can see here is that does the water split into its constituents, probably not, as this would require something akin to a nuclear reaction--not ideal in a car unless you want to go back to the future, secondly water has a low viscosity and thus can get past rings/valves contaminating oil and rusting delicate bits like cams etc, thirdly water is incompressible (well in reality it compresses about 1/2% per 1000 psi but thats not important) so any water condensing or not flashing off would cause hydraulic lock, this would be even furthur apparant if on a diesel due to its higher comp ratio, finally have you ever driven a car with a slightly leaking head gasket, power is reduced and there are clouds of white smoke.

now over to you lot to shoot me down in flames

[admin]

Hi Gillberry

Do you have any photos of the SD1? been quite a while since I saw one of those out and about

Scotty, from memory the water injection upped the power of the 99T from 145bhp to about 185, so must have felt like quite a jump. I never drove one but I hear that the only problem with the 99T was heavy steering, and no room to fit a PAS (although I'm sure its been done since), which of course the 900 had. If I could find a good 2dr I'd be tempted

Rick

[buzzy bee]

Hi

Cheers for the explanations, now I have an idea I will have a look into the subject!!

Cheers

Dave

[gillberry]

My baby ;


My baby and her good shell ;

My other halfs cars (2 of ) guess who has to work on them ;

[buzzy bee]

Could be worse, your other half might not have liked old cars!!

[Uncle Joe]

xk, as if we would shoot you down in flames regarding water injection.

Basically, I think things can be explained a little simpler. Water is injected into the intake air to cool it down. This reduces secondary detonation (pinking). Which in its turn means that higher compressions can be used, to give more power. Or you can use lower octane fuel!

Liken it to the fact that an engine gives more power on a cold day than a warm one.....which is really the reason a car slides on ice. More power

UJ

[PACresta]

68 Reliant Robin Supervan (past my test at 16 in it)
60 VW Split Screen Devon Camper (Wished i had it now) Paid £50 with no engine in it. Got 2nd hand engine and away we went
68 1300 Beetle

71 1300 Beetle
73 1303S Beetle
72 Triumph 2000 (Very unreliable) Had designs on wanting a bigger car
75 1800 Marina
74 1303 Beetle
72 VW Camper (Interest rates went to 17.5%, had to sell.
72 850 Mini (Had this given me by a kind friend) Replaced rear subframe and away we went.
74 1300 Avenger
72 1303S Beetle
80 VW Derby
73 1303 Beetle

82 VW Passat

72 VW Camper

68 Camper

84 Audi 80

88 Audi 80
90 2 LTR Granada Saloon
96 2.3 Scorpio
62 PA Cresta (First Classic car)
60 PA Cresta (Subject of current reston) www.pacresta.co.uk
2000 2.3 Galaxy

Quite a list i know, used to change cars like socks Probably missed a few out, will add photo's if i can dig any out.

[Uncle Joe]

Scotty, I never actually sold the H120, it got stole, never to be seen again. Sometimes, I do still wonder if it still exists or what happened to it.

UJ

[gillberry]

He put his list on now for my one - renault 14gtl - astra mk2 - astra mk2 (he wrote off) - his humber hawk estate - vauxhall firenza (he was driving when it was written off not his fault)- astra mk1 - astra mk3 estate (he was driving when it was writen off again not his fault) - and still have at the moment - astra mk3 estate - 1965 viva ha - 1966 humber sceptre & one for spares - and of course the latest thing with wheels the cheltenham caravan

[Scotty]

[dpr]

[Scotty]

I forgot to mention I had a 1952 Ford Anglia as well - knew that wee car inside out and loved its 10 hp engine to bits.

[john-saab]

To follow on from the water injection system conversation..SAAB used a system (on some 99's) that sprayed cold water over the intercooler "radiator"..cooling the air passing through it...this did produce more BHP but boy did cars fitted with it rust in that area.

[dpr]

I love early Corvettes'



In fact, I think new ones have the same suspension design

But my one true love, automotive that is.



Made in Norfolk UK.