In Stock


( £112.50 EXC VAT )

One of the lightest and highest quality duplex vernier timing gear sets available for the A-Series engine. Comes complete with IWIS competition timing chain.

We have re-designed our original alloy vernier timing gear set and the complete cam sprocket assembly is now machined from 7075 aerospace aluminium with extra lightening by the way of large arched slots in the sprocket. It's finished with 7075 aluminium clamping washers.

The crankshaft sprocket is CNC machined from steel and now comes with an extra deep keyway and a full radius machined into the rear of the bore. This eases fitment to EN40B steel crankshafts that have no undercut machined into the rear of the sprocket mounting diameter.

This setup will fit all standard A-Series crankshafts without modification.

The timing gear set comes as standard with:

  • Iwis high quality timing chain
  • 2x Allen countersink screw for the engine plate
  • 3x Allen cap screws and spring washers to mount the camshaft triangle

Which cam timing setup is best?
The choice comes down to personal preference and usage. As a general rule we'd recommend the following:

Steel/alloy vernier duplex - High mileage road car, trackday and competition, 1.35kg.   
All-alloy vernier duplex - Weekend road car, trackday and competition, 0.9kg.
Alloy simplex race - Trackday and competition, 0.65kg.

By nature, the steel outer teeth of the steel/alloy setup are better suited to higher mileage applications. The all-alloy type teeth are machined from a tough 7075 aerospace aluminium and will withstand vigorous use, however, so many are used effectively on the road.

Is lighter better?
The simplex type is aimed at race engines where every last gram matters, but we would not recommend this for regular road use. The lighter the rotating components in a racing engine, the faster it will be able to accelerate to its peak power band high up in the rpm range. On a standard or mildly tuned road car that's less of a concern.  

Do I keep the tensioner?
No, the MED duplex vernier is designed to run without the standard chain tensioner.

What should I torque the fixings to?
The cap head adjusters do not need to be excessively tight. Either tighten by hand with an Allen key, or torque to 12 lb.ft if you have a small enough torque wrench. The camshaft lock nut should be torqued to 70 lb.ft with the locktab in place.

How about the belt drive conversion?  
The belt drive conversion aims to reduce potentially damaging harmonics in the valve train and is considered to be the ultimate setup by many. We fit and use all types of cam timing setups in our engines and kits.