Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - An engine cycle where intake valves only open in the last part of intake cycle?

Big time · 07-20-2013, 01:18 AM

Would this work?
Has this been tried before?

If during the intake of the 4-stroke cycle
intake valves remain closed, say, during the first half of the piston downward travel.
Some vacuum MIGHT form during the piston downward travel.
Then during the last half, the intake valves open, sucking air fuel mixture all of sudden.

I said MIGHT as some warm exhaust gas might be intentionally left in the cylinder, which will expand, compensating some of the vacuum created by the piston moving down.

I believe this will reduce part-throttle pumping losses.

07-20-2013, 01:18 AM	#1 (permalink)
Big time EcoModding Apprentice Join Date: Dec 2011 Location: Miami FL Posts: 121 Thanks: 1 Thanked 16 Times in 10 Posts	An engine cycle where intake valves only open in the last part of intake cycle? Would this work? Has this been tried before? If during the intake of the 4-stroke cycle intake valves remain closed, say, during the first half of the piston downward travel. Some vacuum MIGHT form during the piston downward travel. Then during the last half, the intake valves open, sucking air fuel mixture all of sudden. I said MIGHT as some warm exhaust gas might be intentionally left in the cylinder, which will expand, compensating some of the vacuum created by the piston moving down. I believe this will reduce part-throttle pumping losses.