LC Engineering has provided the racing industry with a performance kit that includes a 4" Single Groove Crankshaft Power Pulley, 7" Billet Water Pump Pulley and an Adjustable Timing Tag, see Part# 1016124. We just recently developed a kit for the Street Customer that includes the 4" Triple Groove Crankshaft Power Pulley, a 6" Billet Water Pump Pulley and Adjustable Timing Tag, see Part# 1016120. Underdrive Pulley Kit's are basically used to slow down the revolution speed of engine accessories such as water pumps, alternators, a/c pumps, etc. This type of set up will assist the engine in gaining more usable horsepower to the rear wheels.
Because of the extreme RPM ranges on Race applications, we recommend our 4" Single Groove Power Pulley and the 7" Billet Water Pump Pulley with Adjustable Timing Tag. On Street applications we suggest using our Triple Groove Power Pulley at the crankshaft and the 6" Billet Water Pump Pulley with Adjustable Timing Tag. We do not recommend, however, any underdrive kit on low RPM applications such as rock crawling or commuter traffic.
An Adjustable Timing Tag is required when converting to a 4" Crankshaft Pulley which take's the place of the original timing tag that is located on the oil pump. To adjust the Timing Tag correctly, find indicated top dead center on the #1 piston, set the pointer to the 0 (zero) mark on the pulley and tighten it down. You will now use the pointer on the timing tag to set correct timing.
Modification made to existing oil pump for installation of timing tag.
Underdrive Kit after installation.