Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post

steffen707 · 04-20-2012, 04:32 PM

I was thinking today about the VX lean burn engine, and I have read that only one of the intake valves opens all the way, the other partially opens to create the swirl to mix up the fuel/air.

I've also read that lean burn engines get awesome fuel economy when in lean burn, but only okay gas mileage when not in lean burn.

Is this mediocre gas mileage a result of the 2nd intake valve only opening slightly? Would you get better gas mileage if the valve opened all the way like a normal D15 engine?

If this is the case, couldn't honda have just activated the Vtec solenoid whenever the car wasn't in lean burn? Thus giving you better mileage? And then when conditions were right to put it into lean burn, the vtec solenoid would just be turned off, thus causing the 2nd intake valve to only open a little bit to make the swirl?

04-20-2012, 04:32 PM	#1 (permalink)
steffen707 Master EcoModder Join Date: Oct 2009 Location: Midwest Posts: 337 Thanks: 4 Thanked 37 Times in 21 Posts	Improving lean burn I was thinking today about the VX lean burn engine, and I have read that only one of the intake valves opens all the way, the other partially opens to create the swirl to mix up the fuel/air. I've also read that lean burn engines get awesome fuel economy when in lean burn, but only okay gas mileage when not in lean burn. Is this mediocre gas mileage a result of the 2nd intake valve only opening slightly? Would you get better gas mileage if the valve opened all the way like a normal D15 engine? If this is the case, couldn't honda have just activated the Vtec solenoid whenever the car wasn't in lean burn? Thus giving you better mileage? And then when conditions were right to put it into lean burn, the vtec solenoid would just be turned off, thus causing the 2nd intake valve to only open a little bit to make the swirl?