Yup, the check valve is exactly what I was thinking with my evap line solenoid idea. (the check valve is also a bit of a holdover from the days of carburetors)
(I only have a fuel supply line from my tank - no return. and I also have an EFIE on my upstream o2 sensor for the computer to trim injector pulse width to try to hit 14.7:1 air-fuel ratio)
EDIT - now that I've seen the whole video, that check valve is a lot simpler than my electronic hack/mod idea. Further, the idea of dropping crankcase pressure - TracyG sent me a BMW air-oil cyclone separator. I put it on my breather line, with the drain going into the PCV line through a needle valve (so there's always a slight bit of manifold vacuum on the breather pressure, but the air is all still metered so as not to confuse the computer). In a way, it kinda balances out top and bottom pressures in this config, and yes, I have noticed a bit of a difference in performance. Ron might disagree about not capping the PCV system/port, but I like the way it's been going so far. Edit 2 - actually, now that I've watched the longer video as well, Ron had his own takes on some of the things Mike talked about there, too. This is good - I like testing ideas (it's why I've been here Grooving for so long, and testing away with various thoughts and methods) because I'm a firm believer there are more ways than one to accomplish things. Mess with things until they work better, friends...and try not to mess them completely up lol.
Back to the topic at hand - everybody also has an EGR valve/system - that factors into the mix in the intake as well. the dry fuel vapours Mike mentions mix with warm moist exhaust in certain circumstances and combinations...based on what factors according to the computer? <- this is what we need to reverse engineer so we can hack/exert influence if not gain outright control:
With the US President choosing to draw down strategic petroleum reserves to keep prices at the pump from spiking to keep the economy moving along (while encouraging OPEC to pump more yet shutting down pipelines from significant continental sources), there will come a time sooner than later that there will be rationing of fuel and increased interest in the Groove. (Unless miraculously, EVs have some sort of magical breakthrough in terms of range and the power distribution network steps up to big oil and says "we've got this" and takes over the filling station networks). (actually, this will hit diesel harder/faster than gasoline - farms run on diesel and there's a significant potential to get starved to death...)
sorry for the divergence there...
make ready friends - we're gonna need this knowledge sooner than later.
FRANKLY - rather than preheating fuel, we need to find ways to vapourize it better at the right time, and regulate that into the combustion chamber. I think our groove does a great job of mixing fuel and air, but we're measuring 14.7:1 at the wrong time/place for efficiency. we have the technology to do better, and keep it simple. Balancing vacuum and crankcase pressures is one of those simple ways.