The S&S crankcase oil passage drilling jig is used to perform crankcase drilling modifications when installing an S&S oil pump assembly on early big twin crankcases. Made of hardened steel for durability, this fixture enables the builder to do four modifications. 

 

Drill jig is used to drill:

Primary chain oil supply passage from the breather valve gear cavity to the back side of the oil pump body on late generator and early alternator crankcases.

Pressure relief passage from behind the main oil pressure valve to the gear cavity on alternator crankcases.

Crankshaft and main bearings supply passage on generator crankcases.

Crankshaft and main bearings supply passage on early alternator crankcases.