When building a stroked motor, you must carefully check the engine for clearance. On an LS the clearance to the bottom of the bores is the close point for a stroker motor. We believe that you should not exceed a 4″ stroke on a stock LS block because of clearance in this area and also because the piston extends too low below the bore with longer strokes.
When a longer than 4″ stroke is used, a lot of the piston skirt pokes down past the bore and the piston loses stability about bottom dead center. This causes the piston to rock violently which leaves chatter marks in the bore and wear marks on the piston. The bore and piston skirt wear a lot faster because of this. There is some evidence of this happening on a 4″ stroke even but we think it is not too bad and a drift car needs the torque a longer stroke gives.
Stay tuned, in our next article about Falken’s new motor, we will be assembling the top end and teaching you more LS assembly tricks!