Rnd Motorsport adjustable cam pulley's - Z20 Engine



Z20 Engine Adjustable Cam Pulleys


Installing the pulley


Before installing your new cam pulleys please make sure you have the correct tools to do the job, also make sure you are familiar with what you are doing. Using improper installation tools to lock out the cams prior to pulley removal may cause damage to the RnD pulleys. We prefer the use of the plastic moulded type cam locking tool.


Remove old cam pulleys, inspect the end of the cams to make sure they are free from damage, ensure your new RnD pulleys fit onto the end of the cams and are free from defects. Check and clean all mating parts before re assembling. Fasten the pulleys to the camshafts as per Vauxhall intended ( 50Nm +30 deg + 30 deg ). A new bolt is recommended. Check the locking bolts are tightened to 10Nm.


The V3 cam pulley is designed to be used on both the intake and the exhaust cam. There are two different dowel positions marked "IN" and "EX", these translate to inlet and exhaust respectively. When installing your cam pulley to the camshaft, looking at the pulley please make sure to install the dowel pin in the correct slot for the position it is being installed in. i.e. – When installing an exhaust cam please make sure the dowel pin is located in the slot that is marked "EX". Failure to follow this instruction may lead to engine damage. For those already quite familiar with the Z20 engine, you will see that this idea is similar to how the standard exhaust pulley already works.


Timing the engine




The pulleys come with markings giving +/- 10° adjustment either side of standard timing.

When timing the engine and installing a new cam belt please make sure that the correct marks are used to indicate where the cams are in relation to TDC. The inlet cam uses the shorter timing mark of the two, the exhaust cam timing mark also doubles up as the marker on the adjustment scale.


Adjusting the pulley


These pulleys come pre set at standard timing, ready to install. The picture shows the pulley set at standard timing / 0°.

They can be adjusted either during tuning or during the engine build process with a degree wheel by slackening the 5 bolts enough to let the cam be rotated within the pulley (using a torx socket on the central bolt with a T-bar gives nice feel / control over the adjustment). Rotating the cam clockwise advances it and anti-clockwise retards the timing. Each one of the marks represent 1° at the cam / 2° at the crankshaft. Re-torque the bolts to 10Nm once you are happy.


Thanks for purchasing your RnD product, be sure to contact us if you need anything else.