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Old 03-03-2012, 01:02 PM   #104 (permalink)
drmiller100
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Quote:
Originally Posted by Ecky View Post
Sounds essentially like a diesel with a spark plug. I'd be interested in hearing some educated opinions as to why we don't do this. Emissions? I find it interesting that this system could potentially do-away with an O2 sensor.

Honda (and probably others) has tackled this with variable valve timing. Their newest Civic engines don't have a throttle plate, but instead leave the intake valves open into the compression stroke and close when the right amount of air is left in the cylinder to combust @ their ideal AFR, which solves to problems at once - no pumping losses, and vastly improved emissions.

I know there are also engines (Honda V6's?) that shut off 3 cylinders and leave both intake and exhaust valves closed when driving under low load conditions. This additionally reduces the energy lost pushing air through those cylinders.
I was not aware of Honda doing this. Thank you.

At the moment this is a thought experiment, but I am planning to try this on one of my wounded old honda civics. I was going to run it with an O2 sensor, and leave it closed loop.

But, now that I think about it, I cannot run an O2 sensor. That is probably one problem. Another problem is probably keeping the CAT lit.
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