DKJones96
11-03-2006, 05:45 PM
At idle, an internal combustion engine is at it's worst efficiency. Having to pull the piston down hard against a vacuum and not getting much work out of it because of the small intake charge. Granted, an engine can idle way longer than it can sit under load but it's efficiency is extremely low. This also holds true for en engine while at part throttle say on the highway the engine works hard against the vacuum that is created in the intake because of the throttle body. The idea here is to rid the engine of having to work against the vacuum.
The idea is to equip a Toyota 5M-GE I6 with a high pressure hydraulic system on the intake side only that will replace the cam altogether. Instead, a hydraulic system with actuators will hold the intake valves open allowing you to hold the valve open as long as you need to. At idle you might hold it open thru it's entire normal intake stroke and say 7/8ths of the compression stroke to purge the air from the cylinder again. This would result in some losses as it has to repump the air out of the chamber but not near as much as the losses from pulling down against 18-23inches of vacuum would. This would mean that you do away with the throttle body completely and just close the valve erlier in the compression stroke to increase the engines charge at TDC of the compression stroke. This of course means the engine has to have a direct chamber fuel injection. I've thought about this and the system can be further enchanced with a variable compression system
This is how it would work:
At idle your engine is running at say 1/16ths displacement so a 5m would essentially be a .175L engine running wide open at say 10:1 compression. Then you hit the throttle, the hydraulic system backs off to halfway thru the compression stroke increasing displacement to 1.4L and dropping off the compression system to account for the larger charge at TDC to give you 10:1 again. At 50% you've got the equivelant of a 1.4L I6 at wide open throttle.
This won't add much for you at full throttle except what the direct injection and variable compression system adds but the savings in economy would be incredible. You're talking an engine with the highway/city economy of a metro(or better) and the power on tap of a full displacement 6 cylinder engine.
My CAD skills are a bit sketchy at best so it's taking a while to get a good 3D model of this system but it seems promising, my Cressida will love me...lol
The idea is to equip a Toyota 5M-GE I6 with a high pressure hydraulic system on the intake side only that will replace the cam altogether. Instead, a hydraulic system with actuators will hold the intake valves open allowing you to hold the valve open as long as you need to. At idle you might hold it open thru it's entire normal intake stroke and say 7/8ths of the compression stroke to purge the air from the cylinder again. This would result in some losses as it has to repump the air out of the chamber but not near as much as the losses from pulling down against 18-23inches of vacuum would. This would mean that you do away with the throttle body completely and just close the valve erlier in the compression stroke to increase the engines charge at TDC of the compression stroke. This of course means the engine has to have a direct chamber fuel injection. I've thought about this and the system can be further enchanced with a variable compression system
This is how it would work:
At idle your engine is running at say 1/16ths displacement so a 5m would essentially be a .175L engine running wide open at say 10:1 compression. Then you hit the throttle, the hydraulic system backs off to halfway thru the compression stroke increasing displacement to 1.4L and dropping off the compression system to account for the larger charge at TDC to give you 10:1 again. At 50% you've got the equivelant of a 1.4L I6 at wide open throttle.
This won't add much for you at full throttle except what the direct injection and variable compression system adds but the savings in economy would be incredible. You're talking an engine with the highway/city economy of a metro(or better) and the power on tap of a full displacement 6 cylinder engine.
My CAD skills are a bit sketchy at best so it's taking a while to get a good 3D model of this system but it seems promising, my Cressida will love me...lol