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Thanks Chris and Jojo,
Yeah so far I have not run into anyone who knows much more about it than articles or research. I think 04 was the earliest model year that saw DFI in a production car in the last two decades(for gasoline obviously diesels already do it).
I will in no way pretend to have the automotive skills to convert to DFI. I would definitely just have to find a vehicle(2009 lincoln MKs) with that engine and rip it out. Realistically I would have to wait for them to produce an L4 DFI with injection controlled throttle(probably civic will roll out with a package like this by 2010).
The reason I asked about valve temperature gradient is because I had an idea regarding increasing air flow to the cylinders(which only matters if your engine is fuel injected throttled, otherwise its like you're pushing the gas pedal down further.)
Since there is nothing special about the air before it gets into the cylinder(no fuel added till then) there is no reason you couldn't expose it to potentially very hot valve heads. Hopefully I have not overlooked something to be a serious problem, but you could use your exhaust valves as intakes and your intakes as exhausts.
No superchargers, no butterfly valves, and no complicated overpressure shemes with springs to make sure one side is open and the other is closed. Think distributor cap. Put a small cylinder above the head that has an open top and bottom. valves enter from the top and exit into the head at the bottom. Cylinder has a wide-mouthed opening larger than the air intake tubing. The cylinder would need an opening that runs a quarter or 90 degrees around. We don't want any time when the exhaust is open to the intake. . .but we want it to be a very very short transition.
Cylinder rotates at the same speed as distributor cap or the crank shaft.
> = cylinder opening
-cold air intake- > Intake stroke
___________exhaust
-cold air intake- V compression
___________exhaust
-cold air intake- < combustion/expansion
___________exhaust
-cold air intake- ^ exhaust
___________exhaust
repeat intake
Obviously the manifolds would not be 180 degrees opposed anymore. The cylinder would need to rotate quickly between exhaust and intake because it only has a few degrees of piston movement to make that happen.
Another possible solution coupled with the 90 degree bend(opposed to 180) would be to use electric motors that could very quickly cycle back and forth between near free-wheeling(compression, expansion and intake strokes) and high output(between exhaust and intake strokes).
Anyway theoretically it would give you access to all (4 valves for me) valves for intake and exhaust, thoroughly expelling all heated gases and allowing the chamber to cool more significantly, and intaking a good bit more air at less pumping losses in the intake, while also cooling any surfaces that may cause pre-ignition(or decrease the overall thermal stress and increase everything's lifetime).
Thats why I ask about DFI
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