The Kempner Power Wagon Museum
DETERMINING ENGINE DISPLACEMENT
QUESTION: How can I tell the difference between a 218 c.i.d. and a 230 c.i.d. engine?
Someone told me to count flywheel bolts or remove engine head to measure piston stroke.
Remove the pipe plug over the number six piston. Insert a straight rod, wood or metal, and let it rest on top of the piston. Use the movement of this rod to indicate piston position and to measure piston travel. Use the starting hand crank and turn the crankshaft until the piston reaches the bottom of its stroke - bottom dead center. (If your truck did not come with a hand crank, you can turn the crankshaft by applying effort to the fan blades.) Mark the rod. Then continue to turn the crankshaft the same direction until the piston reaches the top of its stroke - top dead center. Again, mark the rod. Remove the rod and measure the distance between the marks. That is the stroke. The stroke for the 217.76 cid engine is 4 3/8". The stroke for the 230.2 cid engine is 4 5/8". The bore for both is 3 1/4". Replace the pipe plug. The pipe plug is also removed to set timing. But you didn't ask about timing.