Jaguar XJ40 (XJ) 3.2, 3.6 and 4.0 with AJ6 engine from VIN...500001 to 708757 (1986-94) plus 6.0 V12 from VIN...667829 to 708757 (1992-94) • XJS 3.6 with AJ6 engine from VIN...108026 to 179736 (1982-91), 4.0 with AJ6 engine from engine no. 173794 to 196089 (1991-94) plus 6.0 V12 from VIN...188105 to 226645 (1993-96) • X300 (XJ) 6.0 V12 from VIN...720125 to 812255 (1993-97)
Adjusting the valve lash using shims therefore has a number of design advantages that are used in many demanding engines. These include: Many high-revving motorcycle engines, some Alfa and Fiat machines or even the current Jaguar AJ8 engine
When it comes to adjusting the valve clearance, you need a micrometer screw, a calculator, a variety of shims in the back, a feeler gauge and a lot of patience. That's why valve clearance adjustments with shims are considered difficult, but this is not true: With a system and the right tools, valve lash adjustment is quite feasible:
If you do not want to leave the engine open, make sure you have a sufficient supply of shims in advance. Used shims without traces of use can be reused, please check the printed dimension with the help of the micrometer screw. Many shims are labeled in inches and metric. Usually it is much easier to calculate with the metric dimensions. Errors in the conversion range occur, please check the plausibility of the selected shims before assembling.
The oversizes from 3.35 mm to 4.50 mm are exclusively available from us. These oversizes are required when standard camshafts have been re-ground. Either as part of an overhaul, or to extend valve opening times. We also carry undersizes from 2.00 mm to 2.15 mm. These undersizes allow the correct adjustment of the valve lash when the valve seat is heavily worn.