Water in a petrol car

darich

Flying-High wrote: »

So where does the White smoke/steam come from on many vehicles with headgasket failure?... Water in the bores being turned to steam.. Hence often the nice clean piston crown nearest the failure due to the steam cleaning action.

Precisely the point I was making albeit a more subtley.

Wig

My opinion is that where the amount of water is small, from this scenario or from a slightly leaking head gasket, the amount of water in the cylinder is not enough to fill the chamber at full compression, if there is too much water, some of it probably escapes past the rings.

I don't agree with the idea that it escapes through the exhaust valve because on compression stroke both the inlet and exhaust valves are closed.

This scenario is exactly the same as an engine which does not fire because it is flooded (with petrol) these cars are often continually turned over to no ill effect. There is probably simply not enough liquid squirted through the injector to ever cause a problem because that liquid escapes somehow from the cylinder, the only way I can think of is past the rings, with a smaller amount through the exhaust when the exhaust valve is open.

In a car with a leaking HG whilst it is running the water would turn to steam and be ejected through exhaust. However when turned off, it seems possible that enough water could enter the cylinder to cause serious damage next time it is started.

At the end of the day we are all guessing


Bottom line is IMHO the fuel pump & fuel pump reservoir is going to need removing and replaced possibly cleaning will be enough, and maybe it would be wise to clean the fuel system, fill with fuel, re-fit original (cleaned) pump and run the pump (by bridging the relay) into a jam jar at the engine end, if it is pure petrol in the jar and continues to be, then it should be ok to keep the old pump.

You would then need to remove plugs and be fairly happy that there is no excess water in the cylinders before trying to start it.

skiddlydiddly

I have an aquamist water injection kit(yes I have chosen to inject water into my cylinders ) and the pump for it operates at 100 psi.This is enough to atomise the water.Engines operate at a higher compression than this so wouldn't the small amounts of water being delivered through the fuel injectors also atomise?If this is the case and the exhaust and inlet valves are both closed during the combustion stroke, then the water would still be under higher than atmospheric pressure on the down stroke so when the exhaust valve opens the vapour is going to want to travel to an area of low pressure and pass through it?

By the way, you might get away with the fuel pump as I've read accounts of people using them to power water injection systems for sevveral months before they gave up the ghost.

Wig

skiddlydiddly wrote: »

I have an aquamist water injection kit(yes I have chosen to inject water into my cylinders ) and the pump for it operates at 100 psi.This is enough to atomise the water.Engines operate at a higher compression than this so wouldn't the small amounts of water being delivered through the fuel injectors also atomise?If this is the case and the exhaust and inlet valves are both closed during the combustion stroke, then the water would still be under higher than atmospheric pressure on the down stroke so when the exhaust valve opens the vapour is going to want to travel to an area of low pressure and pass through it?

If water is atomised into the cylinder and there is no combustion, then on the combustion stroke the pressure will increase returning the water from a vapour to a liquid, so a few drops will liquify in the cylinder, eventually after enough combustion strokes (without combustion and more water on each stroke) there will theoretically be a build up of water in the cylinder/combustion chamber. There will always be some escaping on the exhaust strokes, but logic tells me that more liquid would enter the chamber than could escape in vapour form from the chamber. So either it has another way out (past the rings) or the amount of water injected is so minimal that it would take too long to become of sufficient quantity to cause a problem. i.e. you'd get a flat battery long before you had too much liquid in the chamber.

By the way, you might get away with the fuel pump as I've read accounts of people using them to power water injection systems for sevveral months before they gave up the ghost.

It's more of a concern about water being present in the fuel pump than a concern of the fuel pump being broken or damaged. Some cars fuel pumps have a large reservoir tank inside the petrol tank containing 3/4 litre (three quarters of a litre) of fuel, if this 3/4 litre is full of water it needs to be drained/cleaned or replaced.


Another possibility not mentioned/discussed yet is that water is maybe too thick/viscous to be passed through the petrol injectors, if this is the case then the injectors will need replacing.

Pew_Pew_Pew_Lasers!

bigjl wrote: »

Actually no, the water is more likely to force the exhaust valve shut, and the engine was running when the water would have been injected, you don't think that the temperatures in a running internal combustion engine are quite high do you, I do.

You have absolutely no idea how long the engine had been running, and neither do I, but no matter how hot it was you're still talking !!!!!!!!.

bigjl wrote: »

Have you ever heard of hydraulic lock, the most common case of this was in early DCI Clios, the air intake was very low to the ground, water was drawn up, through the air filter, into the engine, result bang, and no the water wasn't expelled out the exhaust valve in these cases either.

Half a litre of water in a cylinder is going to do a lot of damage. A fraction of a teaspoon of water entering the cylinder through the injector (not the air intake) will do !!!!!! all.

bigjl wrote: »

So, actually you are talking nonsense, please feel free to furnish us with your example of a car that ingested water, via the fuel system or induction system in the cylinders whilst running and not been damaged, as I have furnished you with an example that was well known at the time it happened, and yes Renault did try to pas the buck onto owners, even though the depth of the puddle which could cause damage wasn't actually that bad.

Congratulations on not understanding how an engine works. You do realise that fuel comes from one place, and air another - don't you?

bigjl

Pew_Pew_Pew_Lasers! wrote: »

Half a litre of water in a cylinder is going to do a lot of damage. A fraction of a teaspoon of water entering the cylinder through the injector (not the air intake) will do !!!!!! all.



Congratulations on not understanding how an engine works. You do realise that fuel comes from one place, and air another - don't you?

Well I somehow doubt that you could get half a litre of water into a space that is 400cc in size.

On the second point it doesn't matter where the two things come from, they both end up in the combustion chamber you halfwit.

How would you expect a car to run without a precise mix of fuel and air?


The only thing you have added to this discussion is abuse and ignorance.


@Skiddlydiddly, I was led to believe that things such as the aquamist system used water to cool the air entering the engine, thus making it more dense, therefore giving more power. But as I have never looked into these things in any detail then you are probably correct.

@flyinghigh, as far as the steam coming out the exhaust when a head gasket fails, that is correct, but the engine is running and the amount going in is small, so the heat would turn it to steam I would assume.
Though I believe that enough water in the bores will indeed sieze the engine, since there is always a bit of contamination in petrol then I would assume there is apoint where the engine can't cope with amount of water, hence hydraulic lock and bent valves.

I think I will put pew pew on ignore as he seems to only interested in abusing people without attempting to debate a point.

But before I start to ignore him can he or she explain the point he made withthis comment

"Congratulations on not understanding how an engine works. You do realise that fuel comes from one place, and air another - don't you?"

Remember the old phrase, all roads lead to Rome, though if the engine in your car doesn't direct the air and fuel to the same place I suggest calling the AA and get it towed to the garage something isn't connected.

Pew_Pew_Pew_Lasers!

bigjl wrote: »

Well I somehow doubt that you could get half a litre of water into a space that is 400cc in size.

I didn't look at the engine size, it was an estimation.

bigjl wrote: »

On the second point it doesn't matter where the two things come from, they both end up in the combustion chamber you halfwit.

How would you expect a car to run without a precise mix of fuel and air?

Halfwit? Do you really think that air and fuel are added in equal quantities? Injectors spray tiny amounts of fuel into the cylinder. Mixed with a relatively large volume of air. If you really think that enough liquid is ever injected into a cylinder to cause some kind of damage, then you have absolutely no idea what you're talking about. If engines ran how you say they run, any petrol car that had a spark plug failure would tend to destroy its engine. Obviously this never happens. Get it?

bigjl wrote: »

The only thing you have added to this discussion is abuse and ignorance.

No, I've highlighted your ignorance, it's probably one of the easiest things I've ever done.

bigjl wrote: »

I think I will put pew pew on ignore as he seems to only interested in abusing people without attempting to debate a point.

Thank !!!! for that, I won't have to reply to your idiocy.

skiddlydiddly

Bigjl-yeah they reduce inlet temps a lot so can advance timing and run more boost as well as steam cleaning your pistons .If you mix it with methanol it also raises the octane significantly.

andyg9053

might seem a bit of a waste but scotch mixes with water and still burns, my grandfather an old fashioned mechanic did this as it was cheaper than stripping an engine. he always used a whole bottle, but i dont know what ratio you would need having put in so much water.

the hydrolock mentioned earlier is when the water is sucked in the air intake and as another poster said the ratio is 20 air to 1 petrol, that means the cylinder is full of fluid now and no fluid doesnt compress, otherwise hydraulic systems wouldnt work, simplessssss

optimus_primera

I have some experience of 'wet' engines, albeit thru taking old landies thru deep water.
Firstly, its more common to destoy Diesel engines thru hydraulic lock than petrols, mostly due to higher compression ratios,and (in the case of 'older' diesels) no engine electrics to pack up when they get wet.
Not going to get embroiled in the how much water it takes to kill an engine, as it depends on the motor, and how it entered the engine etc


Back to the original question.
Drain the fuel tank, remove the filter ( and any other inline filters their maybe)Remove the fuel pump.(disconnect battery first)
Flush these thru with fresh fuel/thinners/meths etc. and allow to air dry completely.Disconnect fuel line from tank.
Moving to the engine bay, trace all the pipework, and disconnect fuel line from engine,(you can flush this pipe thru with a syringe full of above mentioned substances,air blow thru with air line to dry out) doing it this way is easier than lying on your back under the car.
Remove spark plugs and allow them to dry,take out injectors if you can.
Disconnect coil, reconnect battery and spin engine over to eject any remaining water from cylinders.
If you could not remove the injectors then I would reconnect the fuel system,fill with fresh petrol, however leave sparkplugs out and coil disconnected,and spin engine over to 'flush' the injectors thru.
Goes without saying, to ensure the risk of fire from atomised petrol is minimised.

In my experience there is no easy answer to say how quickly it will run, they can go first time, or take ages to get going .......