Steam Injection

Beadle

Beadle

Well-Known Member
Joined
20 Aug 2007
Messages
6,744
Location
Rural Nth Yorks - 2 miles from bus stop, 8 miles f
Visit site
The steamboat thread reminded me of a steam injection system that was on sale some 30 years ago.

Basically you brazed two thin copper tubes through the exhaust manifold to boil the water and plastic and copper tube to a nozzle in the carburetor inlet.

There was a water bottle with electronic pump controlled so as to keep a constant level of water in the "boiler"

It was supposed to improve mpg and low revs torque.

I fitted it on my old landrover and it did seem to work to some extent. I never measured the mpg - you don't do that on a 2.25 Land Rover engine.

I eventually took it off because the electronics were not up to the job and flooded the "boiler" which sent water into the carb - that certainly didn't improve anything.

Wonder if anyone else has tried it
 
Many moons ago, when I was in the FAA at Boscombe Down, the Chief Tiff fitted an extra jet into the carb on his Ford 105E to allow water to be drawn into the cylinders.

I don't know if it worked well or not, or how often he refilled the water tank.

That was in the days when we could modify a car without notifying DVLA. I dropped the front suspension on my Imp and shortened the springs. Made a world of difference to a rear engined car - with an 875cc engine!!!

Them's were the days!! :cool:
 
I recall tests on a similar system in the 70s that involved drilling a hole in the inlet manifold and dripping water in.

IIRC the claim was that it increased MPG
test result - yes it did

then they tested with the hole but no water
test result - improved mpg

then they fed water in to the manifold without the hole
test result - improved mpg

then they filled in the hole so back to square 1
test result - improved mpg

Overall conclusion:
Snake oil
 
I had one of those "water injection" systems fitted to my first car! It (sort-of) worked, providing barely-measurable improvements in MPG and (entirely subjective!) small improvements in power. Unfortunately, it relied on manifold vacuum to "suck" the water in, and manifold vacuum on a petrol engine is high when the throttle is shut! Worse than that, I over-did it one day and discovered (the hard way!) that water isn't compressible...

I think the theory behind it is that the water cools the incoming air, increasing its density, so you get more of it into each cylinder. Cars tend to run better on damp days for that reason (but in the '70s, the ignition systems were so lousy that this often wiped out any benefits from damp air)! Modern rally cars sometimes inject a fine spray of ater into their intercoolers for the same effect.

I'm not sure if steam would help. On the one hand, it would be more of a vapour, on the other, it obviously wouldn't be that good for cooling the charge!

It goes without saying that on modern car enines. Any such intervention is likely to just result in the engine management light coming on and an expensive trip to the main stealer!
 
Beadle said:
The steamboat thread reminded me of a steam injection system that was on sale some 30 years ago.

Basically you brazed two thin copper tubes through the exhaust manifold to boil the water and plastic and copper tube to a nozzle in the carburetor inlet.

There was a water bottle with electronic pump controlled so as to keep a constant level of water in the "boiler"

It was supposed to improve mpg and low revs torque.

I fitted it on my old landrover and it did seem to work to some extent. I never measured the mpg - you don't do that on a 2.25 Land Rover engine.

I eventually took it off because the electronics were not up to the job and flooded the "boiler" which sent water into the carb - that certainly didn't improve anything.

Wonder if anyone else has tried it
Click to expand...

Hi, In the late sixties I worked next door to a fruit machine company. The foreman was a realy clever bloke who drilled a small hole in the SU HS2 carb. jet and silver soldered a small tube in. This enabled him to fit a pipe connected to a water container with a mechanicaly controled tap. The car was an Austin 1100. When the engine had reached normal tempreture he would turn on the water.The engine would imediatly run smoother and had more torque-at least it would pull a higher gear at a lower speed.It was only tested subjectivly in the absence of any meaningfull test gear,but he was happy and I drove the car many times and noted its clean running and strong pulling.Once he forgot to turn off the water and had to take the plugs out to clear it and subsequenly change the oil.Thats where his expertise with old fashoned relays and magnets fron the pin tables and fruit machines came in. He rigged up a semi automatic system that still allowed the mechanical control for switching on but turned it off when the ignition was turned off. At brooklands in the 20's and 30's alcahol fuel was often used for long distance record breaking. Half a pint of water was added to each gallon of the methanol fuel to help the engines run a little cooler.The water would turn to steam and still act as a gas pushing the pistons down but helped the exhaust valves stay in one piece by giving some cooling.Unlike petrol alcahol absorbs a small amount of water without losing too much power.In long distance races or record attempts reliability was just as important as speed.
 
philip_stevens said:
Many moons ago, when I was in the FAA at Boscombe Down, the Chief Tiff fitted an extra jet into the carb on his Ford 105E to allow water to be drawn into the cylinders.

I don't know if it worked well or not, or how often he refilled the water tank.

That was in the days when we could modify a car without notifying DVLA. I dropped the front suspension on my Imp and shortened the springs. Made a world of difference to a rear engined car - with an 875cc engine!!!

Them's were the days!! :cool:
Click to expand...

Ah the Hillman Imp. I occasionally see one on reruns of Heartbeat. What a great little car. All aluminium slanted 4cylinder rear engine. It might also have been the death of Hillman when at the same time the Morris Mini took off.
Anyway yes water into jet engines was often used to improve take off performance. A jet engine's power is limited by the temperature the turbine can cope with.Water injected both cooled the gases but also expands hugely creating more pressure. I guess the practice has died out with material more able to cope with higher temperatures and the fact that there are very few true jet engines now mostly being fan jet where the exhaust drives a turbine to drive a fan. Most power comes via the fan (a prop jet with a cowl) and power is limited by mechanical robustness as well as temps.
Water injection on cars has been a fact or snake oil idea for many years. Has it been dismissed as too expensive or difficult to make foolproof compared to value of improvements/ One might imagine that water injection via fuel injectors should be fairly simple but no one does it. You might imagine it very valuable in turbo charged petrol cars to reduce detonation. olewill just waffling
 
A nieghbour in Norfolk fitted the kit to his Volvo. It did improve the MPG by a small, but noticable, %. It also corroded the Stromberg carbs after a couple of months, leading to the slides jamming. He polished up the carbs, and took the kit off. Not worth the hassle.
So it did work, but needed development.

As for Imps: The engine was a Coventry Climax that was bought in to speed up the introduction of the Imp. The original engine was an opposed twin, but was dropped for needing too much work for production.
I had the Imp Sport motor in the back of a Ginetta. Gave it MGB performance due to it's light weight and quite the nicest handling car I've owned. Car Mag " This is what the Midget/Sprite should have been like. You will not run out of space on a public road". Never did dispite the loony speeds one drove at in those pre-camara days.
 
Last edited:
I wouldn't have thought sulphuric acid formation would be a problem these days - there's so little sulphur in fuel, compared to the 1960s. The problem is that the benefits are pretty minimal. It's pointless just letting it get "sucked" in because the engine only really "sucks" when the throttle is closed. Injecting it would work, but that's extra expense and weight. Also, unless you're a rally car and you only need to carry a few kilos to get you to the end of a stage, you'd need to carry a fair amount of water on board and suffer the weight and space penalties associated with that. Even then, you'd need to get the owners to top it up regularly.
 
Water injection certainly worked in rifles. In the old Lee Enfield Mk4 .303 days at Bisley, rain presented a real problem in competitions. A drop of water on a round would be enough to create steam, and put the shot over the target at 500 yards range. The solution was to put the rounds to be used in a jug of water, so they were all guaranteed wet, and then to wind the sights down 4 minutes of arc, and, bingo, back on target. Sounds like a tall story, but we really did it, and it really worked....
 
Well, I'm not sure it does, to be honest!

OK, I should probably say that it sucks "most" when the throttle is closed! In a normally-aspirated engine, the inlet manifold, downstream of the throttle plate, is always likely to be at a pressure below atmospheric. On over-run with a closed throttle and high revs, it will be a very low pressure indeed, and that's when I think most of the water would get sucked in. Unfortunately, that's not when you'd need it and most (if not all) modern cars have an over-run fuel cut-off anyway. At idle it will be a smaller depression, and during normal (light throttle) driving, smaller again. During hard acceleration, it will be at its smallest - not too far below atmospheric on a well-designed engine, so hardly any will go in. Modern engines don't have anything like the level of inlet restriction that old carbuettor-equipped engines did.
 
The system I had injected steam into the carb, not the manifold.

The amount of steam drawn into the engine was related to the airflow rather than manifold depression. So I guess the mass of steam injected would rise with engine revs and hence power.

Which I think sounds about right.

I did consider various additives, mainly to stop icing which was a problem in winter, but the electronics failed before I had chance to try it.
 
Yes, I'm sure injecting it would work better - as long as there was some means of metering the amount according to the airflow into the engine. That said, I also wonder about the temperature - presumably, the hotter the steam, the more self-defeating it is becuase you'd loose some of the charge cooling effect (and thus, charge density).
 
You must log in or register to reply here.

Share this page

Top