17-4 SS Bridge Bar

Bridge Bar for 4.25 Piston

Bridge Bar for 4.375 Piston

     CASE MACHINING &  BRIDGE BOLT INSTALLATION

Review the factory procedures  as outlined in the H-D Service Manual for your motorcycle. Be careful to follow all warnings and cautions found in the Service Manual.

We will machine the bottom of the crankcase and tap a hole to receive a  3/8 NPT Stainless steel drain plug.  This hole is needed for inspection of the oil sump efficiency, the trapped oil in the flywheel chamber will help in lubrication of the piston but rob away horsepower when you want to do dyno testing.  This Plug is also used for flushing out the crankcase.   Yamabond #4 crankcase sealant will be used to seal the two crankcase surfaces.

At the top of the crankcase there are two cylinder spigot holes.  These holes will be machined according to our EMC special pattern.  Note the aluminum casting near the cylinder studs are not machined.  This pattern cuts two pockets for each cylinder.  Only the front and back of the piston skirt need guiding  at bottom dead center BDC.  

Eight heavy duty studs are installed using red loctite.  The stock TC-88 studs break at 65 ft # of torque, but these new  studs break at 85 ft # of head bolt torque.  These test were conducted at EMC to ensure the performance of our modified Super TwinCam  motors.