How are the cylinders going to get filled if the valves are closed? It's a carb, so the cylinders that are operating will draw the fuel. Raw fuel is not dropped with a carb, air pulled in by the pistons pull the fuel into the cylinders. Yes, but you're likely to still get some pooling of fuel down in the intake ports, meaning that once you flip the switch and reactivate the cylinder, it'll flood out that cylinder, if pooled enough of course, seen fuel pooling on engines where theyve broken an intake rocker and the intake valve stayed closed. But it may not pool. I honestly can't say one way or the other. and im sure that'll depend on what manifold you run.
What I don't know is that it's jetted for a 5.7L, if it's operating as a 3.35L, will it be pig rich??? Yes, itll run way way rich, you "MIGHT" be able to pull this off if you'd switch to an aftermarket stand alone fuel injection kit that will bolt in place of the carb such as the Holley or Fitech kits. They adjust fueling on the fly so that might help the rich problem.
Why can't I have a TPS on a carb? I do have the harness that has the sensors and solenoids... The factory system is mostly seamless and operates at slower speeds, as well as cruising, I'm interested in cruising speeds. You could try rigging something up for the TPS but where are you gonna send the signal too? You also need to understand that the factory harness and sensors are designed to work with a computer that also changes the timing and fueling of the engine using the inputs from the TPS, fuel injectors, and O2 sensors when it shuts down those 4 cylinders, your MSD box is not capable of doing such.
What happens if the solenoids are turned on and off, without any sensors? I bet it drops the 4 cylinders... Now, like you said, timing of the sequence might be critical to not back fire or pop, maybe it waits till after each exhaust stroke, then closes everything... All of the cylinders that are deactivated have unique mutli- piece, hydraulic valve lifters that collapse when deactivated to prevent the valves from opening. Engine oil pressure is used to activate and deactivate the valves. Sensors are used to determine the oil pressure flowing to each solenoid valve for each cylinder to ensure proper pressure remains on each latching pin. Solenoid valves control the flow. It's not a simple on/off. The solenoids constantly adjust the flow of the oil. When activated, pressurized oil pushes a latching pin on each valve lifter, which then collapses the lifter, preventing the valve from moving. Its base still rides the camshaft, but its top remains stationary, held in place against the pushrod by light spring pressure but unable to move because of the much higher force of the valve spring.
Deactivation occurs during the compression stroke of each cylinder. This all is computer controlled via a complex algorithm to ensure all components function within a fraction of a microsecond(.040 microseconds per Dodge's advertising), ensuring a smooth operation and preventing valve damage.
You'll need all the components to make this work. Including the computer that receives, interprets and sends the signals from the sensors to the solenoids, as well as adjusting the timing and shutting off the spark and fuel to just those 4 cylinders. Youd have to find a way to shut down the spark manually as well.
I'm a ways off from starting it up, but that might be a good experiment even at idle.. Wideband sensors, and power the solenoids on off....
