Quote:
Originally Posted by RustyLugNut
It is more about time of injection. If there is not enough evaporation, large enough droplets will be available at combustion and these provide the basis for the carbon soot. Compression and stroke have little to do with this. Look at modern diesels. They always run lean and they produce soot. And they have strokes and compressions far above what a GDI is talking about. But, the soot formation in a GDI is more similar to the diesel than to a PFI spark ignition engine.
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Hmm, so we get back to the gasoline running in heated pressurized rails again, so it actually atomizes faster (but oh the NOx)
(heat is something that does not really help diesel atomization)
Quote:
Originally Posted by RustyLugNut
A source in Korea has told me that some Hyundai models as well as others have the capability of lean burn depending on the target market. Many countries care little about NOx.
And yes, you are correct, you can limit your water injection to only part throttle. Of course there are in cylinder injection schemes that are worth the effort. You will not be able to leverage that with port water injection.
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Interesting, if a larger car company had a decent small displacement lean burn engine in foreign markets it might be interesting enough to look for used to import (just saying)
Also I have been told water injection and water wash decrease carbon emissions (washes it out of the air)
At least it does in diesels.
Also I am aware of directly injecting water at some point late during the compression or even expansion stroke, it allows you to extract more power out of the charge, use a longer stroke, reduce NOx and carbon and obviously should create better fuel economy, especially in slow turning engines.
Would be interesting to see on a normal car though.
My original thought was port water injection under certain conditions to keep the ports clean, an added side affect is that it can improve fuel economy modestly under certain conditions,
and that technique could probably be combined with direct injection, now we are getting all kinds of complex!
Sort of like me wishing NA diesels had 2 tanks
1. for diesel
and a 2nd for E85 to inject for power during acceleration, properly tuned you could have massive power out and fuel economy out of a normal simple naturally aspirated block without needing the many headaches associated with timing belts and turbos combined with winter operation.
Oh to dream.