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The Swedish Saab, today an aerospace and defence company has been one of the few car builders that have used the system in line-production. Before that, Saab gathered wide experience with water injection in turbine aircraft engines.
The car water injection was available as tunig kit too.
John (JP), the attached PDF file mentiones and shows a special construction, intended for warm climate zones.






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Guscha, thanks for posting that link. Difficult to believe, but Saab USA never marketed that kit. I've driven Saabs for almost forty years and never seen that info published.

jack vines

I, too, have driven Saabs for more than 40 years and never knew of their water injection kits.

In the mid 50s my brother had a Buick straight eight in which he burned the cheapest fuel he could find. The car had a water injector, don't know if it was a Thompson, but it worked beautifully. As long as there was water in the under hood tank (it held a quart or two), the engine ran smoothly and quietly. As soon as the water ran out, it pinged mercilessly. He loaned the car to me for a couple of weeks and I learned to fill up with water whenever filling the gas tank. I can't say that it improved gasoline mileage, but it certainly did permit the lowest cost fuel to be used.

eBay a few years ago had a number used water injection kits for sale. Some may still be available. As I recall they ran in the $40 - $ 60 range.

Bernardi

This is proving to be a fascinating subject the more I read about it. I followed-up Rusty's advice about the Thomson Vitameter and there's not much on the internet, although what I did find suggested a pretty clever concept. From what I can gather, the water injection for it is still achieved through vacuum, but at the low vacuum end of the spectrum where it is more effective. If there was a pump involved I couldn't work out where it was.

The Thomson company was of the belief that use of the Vitameter would mean vehicles would only need what they termed special low-octane straight-run gasoline, which was said to be produced at considerably lower cost than cracked, blended or reformed fuel. I'm not sure exactly what all that means other than it would result in cheaper running costs.

Given the stated advantages of water injection and what looks like something relatively inexpensive to manufacture, I wonder why it didn't take off. Was it one of those things the petroleum industry killed-off? The main issue these days would be how to fit it to the carby - perhaps "T" into the distributor vacuum port. Also, I suppose another port could be machined into the carby base, but something like that is complicating things and might be better left to a specialist machinist. Anyway, I'm thinking I'll continue to investigate this some more for awhile yet. John

As described in my earlier post, one way of getting the water into the inlet manifold is to make a plate to fit between the carburettor and the inlet manifold with a water line attached to the edge of the plate as shown in this advertisement for one such system from about 1960.

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Tried a homemade water "injector" similar to the diagram above back in 70's.
PROBLEM: it caused rusting vavle stems an guides on intake and exhaust, especialy exhaust. Vavles would sieze. Ok to try it on flat heads but i wouldnt chance it on ohv.

The early 60's Olds "Jetfire fluid" was alcohol and water.

The other issue is detonation if excess water leads to liquid entrainment into the combustion chamber.

IIRC water or water/alcohol injection was used on some piston-powered fighter aircraft in WWII, someone (Gusha would be my bet) will no doubt find something on this and post it.

In wartime it may have been necessity where advantages outweighed disadvantages but it strikes me as not a very sound idea in cars to suppress preignition - it probably does that at least in part by lowering combustion temperatures which has it's own disadvantages. If you've got preignition, better to use a higher octane gas or adjust the timing or distributor advance accordingly.

Preignition can be due to excess carbon. That was my problem back in the 70's hence the water injection. It was an attempt to prohibit/blast out carbon. But that was an extremely hot running flathead. Changing from streight 40 weight oil to 20w 50 solved the carbon problem.

Preignition was not the problem at the time bwut rather pistons hitting the head at hi rpm.

To come up to Dave's expectations I scanned the web and deliver general information about the injection version that was installed at the German fighter planes, the so-called MW 50.

A couple of links
Follow this way for getting started.
To go the whole nine yards from the technical point of view check out the Ecomodders. A full evening's programm will be aired if you click on this video link.
Last but not least an interesting side note for edutaining reasons: "The BAC One-Eleven airliner also used water injection for its Rolls-Royce Spey turbofan engines. Filling the tanks with jet fuel instead of water led to the Paninternational Flight 112 crash." (acc. to wikipedia)


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