> But when I read my GM manual, they use it to to cool combustion to reduce NOx emissions,
Yes. > they say it cools the fire enough to change the NOx emissions Yes. Lowers peak combustion chamber pressure and temp. > and is used only at higher throttle settings. Not in all apps, if I recall. Most close it for acceleration. Think its active at cruise rpm. > They say the exhaust gas is inert and thus displaces (reduces) available oxygen Yes, and no. Yes, it is effectively 'inert' for our discussion (but not really, technically). It displaces BOTH fuel and air, the mixture, not just oxygen selectively. Thus the mixture remains almost the same. > wouldn't that really richen the O2/fuel ratio? No. Less fuel AND air. > Isin't richer farther from (and cooler than) detonation rather than closer? Yes. > available oxygen, which has been reduced Not unilaterally, fuel reduced too. > so fuel delivery would be reduced to match, and thus output power is reduced. Yeeesss... But not because of the process you described. It is reduced because you are consuming less fuel and O2. > The engine is starved for oxygen No. > what I am looking for here is an automatic power reduction and this might provide one. Think so. Be nice to do this as a test on an engine stand. I'm interested in your results if you follow up on this. Valley Eng (Culver props?) produce the Generac-based Big Valley Twin. To eliminate carb icing they purposefully ingest exhaust gas, I think all the time. I'd like to know what it does to their peak hp. > GM does not bother with that on my 350. My Suzuki 1300 runs the exhaust through the head next to a water passage. Have no clue how much it cools. GeoB
