ORIGINAL: flat spin
But surely with the engine already tapped and a variable valve one could control the flow anyway. I don't know. I think i am going to have to give it a shot sometime soon i just need a very reliable check valva as i was told if it fails you can easily ed up with a deadstick which in a torque roll means it's all over.
I wonder how much pressure you will end up with? Pressurized tanks can be problematic too, Certain brands won't withstand the pressure and could rupture, also there is a greater chance of the stopper leaking when under pressure. If I were to use the crankcase pressure, I would use it to operate a pump, rather than connecting it directly to a tank. I suppose it depends on the valve you use, as to whether it would be variable. I always used the Bennett valve with that type of system, It worked well, and just had it on the gear switch, it was either off or on, and I installed a standard needle valve off a glow engine inline to control the flow, once it was set that was it, I never tried "mixing" the on/off valve with the throttle, I'm not sure if it would have worked that way. I always made an additional preheater coil, outside the muffler, so the fluid would travel through 2 or 3 feet of hot tubing before it was injected, again this depends on the muffler, some smoke fine without any "mods" but mine worked real good. You will also need check valves in the smoke lines too, as close to the muffler as possible, this prevents the exhaust pressure from fighting the flow of fluid.