Properly Shutting Down A Alky Engine

Try this on for size.......

I was trying to think of the reason why the aluminum rods may not be able to take rapid de-accelaration. At 2:30 last night I came up with a possible reason. During a normal acceleration run the ignition of the fuel mixture pushes the piston down against the top bearing and the shock of the explosion is absorbed through the rod beam and the rod actually compresses some. The upper bearing is fully supported by the upper part of the rod including the beam. On power off, high RPM rapid de-accelaration the piston is nothing but a free weight on the end of the rod that is being thrown out at high speed then yanked back in the opposite direction by the rod. The part of the rod that takes the abuse of changing the direction of the piston travel is now just the bottom bearing and the rod cap with nothing else on the other side of the bearing cap for reinforcement to absorb the shock or offer support. This kind of force probably tries to reshapes the large bearing hole of the rod to an elliptical shape and attempts to squeeze the rod bolts together and bend bearing cap. This in turn with the impact of the sudden change of direction of the piston causes the rod cap to crack.

 

kill switch before fuel

i dont know about the higher comp ratios that the roots cars run, what effect that would have on them. i know thats the way i've killed the car every run, i know that lee callaway kills his blown car like that and alan bradshaw did the same with his blown car...never had any problems of hydraulic lock.

with the lencodrive you pull one gear out to freewheel the motor.