froggyman wrote:
Yes. it is from my personal collection and was the result of driving my Audi through a rather deep puddle. Another short motor and few days work and we were up and running again just in time for a test drive to the South of France.
I remember that problem, a whole selection of vag engines were grenading every time they drove through truck spray, as I recall. Didn't vag do an, um, recall?
Mine won't suffer the same problem so long as the water isn't injected when the engine's stone cold. Even then the most likely outcome is watery engine oil, which the received wisdom suggests will just evaporate out if you run the engine at full temperature for half an hour or so.
There is a simpler version of water injection, a sort of
'Blue Peter' model that achieves this automatically - you just need a header tank that's sited below the inlet manifold but above the exhaust down-pipe to hold the water/methanol mix, a couple of metres of copper capillary tube and a couple of suitable plumbing connectors.
The tube is routed down from the header tank to the exhaust down-pipe where it's wound round it twenty or thirty times before rising straight up into the bottom of the air filter housing, inside of the filter element. The tube that's wound round the exhaust can be heat wrapped to make it more efficient, but that's it.
The water drains down the tube and when the exhaust heats up it turns the water in the windings into steam. The steam can't go back towards the header tank because of the flow of cold water coming down, so it is forced out of the end inside the air filter under pressure.
That gets sucked into the carburettor(s) with the intake charge and effectively raises the octane rating of the petrol to over 100, preventing detonation (pinking) and allowing higher compession, a more aggressive distributor advance, more turbo/supercharger boost or a combination of all of the above. Simple.
