The OHC design of modern engines limits the possibility of surfacing the cylinder head deck without providing for a means of adjusting the gear to gear backlash. The camshaft design of some cylinder heads incorporates individual camshaft towers to mount the camshaft to the cylinder head. Spacing those towers away from the cam idler gear after machining the cylinder head deck will maintain the proper gear to gear backlash. (Reference AERA TB#2836 and 3008)
Innovative Machine Supply provides shims .20″ (.500 MM) to 0.40 (1MM) thick to properly raised the position of the camshaft, allowing the machine shop to surface the head and keep the original casting in service. Cam Tower Shims are currently available for the following applications:
