Editing VVC Information (section)

==VVC Timing Information==

Timing of VVC, text by Dave Andrews (DVA Power), Pictures and additional text by Rob Clarke

Ok...first off we need a cam carrier with the inlet nearest to me so the front of the engine is on my left.

[[Image:vvcrebuild-step1.jpg]]

Fitting the front VVC mechanism to the cam carrier, at the moment this is just held on with two bolt so it doesn’t fall off and fall apart.

[[Image:vvcrebuild-step2.jpg]]

Turn the inner rotating part of the mech. so that the toothed rack on the outer rotor moves in a clockwise direction and the slot in the rotor lines up with the slot machined in the outer support ring of the mech casing at the top centre (as viewed).

[[Image:vvcrebuild-step3.jpg]]

At this point the teeth on the rotor should start pretty much level with the cam ladder surface and extend down and below the surface of the rack radially, effectively from the 3 O’clock position to the 7 O’clock position as viewed from the front of the ladder. The start of the rotors toothed rack should be clearly visible through the break in the casing support ring where the synch. shaft will fit.

[[Image:vvcrebuild-step4.jpg]]

Support the VVC mech. with your hand and remove the two bolts holding the mech. to the ladder, do not let the mech fall away or disengage from the cam. Rotate the mech. slighty anti-clockwise so that the slot which accepts the synch shaft moves upwards a little away from the ladder. Take the synch shaft and enmesh the front end (this has two tooth pinions) into the teeth on the mechs rotor. Rotate the VVC mech back into its correct position and this should bring the synch shaft down into it’s correct position nestling in its bearings. Replace the bolts holding the VVC mech. to the ladder and do them up nearly tight. Rotate the synch shaft in an anti clockwise direction until the pinion teeth meet the end of the toothed track on the VVC mech. rotor and the shaft will turn no more.

[[Image:vvcrebuild-step5.jpg]]

At this point the slot on the rotor and the slot on the mech. casting at the top centre should be pretty much in line.

[[Image:vvcrebuild-step6.jpg]]

Take the rear VVC mech/cam and rotate the inner rotor in an anti-clockwise direction until the slot in the rotor and the slot in the mech housing at the top are in line, when this is done the teeth on the rotor should occupy the 3 O’clock to 7 O’clock positions as with the front mech and it should be a mirror image of the front mech with the end of the teetyh track clearly visible at the point where the synch shaft will fit.

Now fit the VVC rear mech/cam to the ladder while fitting the synch shaft rear end to the teeth track on the mech, There is a bit of a knack to making sure the synch shaft enmeshes in the correct tooth on the inner rotor. Make sure the cam is sitting correctly in its bearings and the VVC mech. is aligned with its bolt holes and then fix the rear VVC mech to the ladder with two bolts and ensure these are nearly tight as with the front mech. Rotate the synch shaft in an anti-clockwise direction until it will not turn any more and ensure that the teeth on each pinion at either end have reached the last tooth on the VVC mech rotor, if they are not exactly in synch then undo the bolts on the rear mech, rotate this anti clockwise a little until the synch shaft can be disengaged from the toothed track and re-synch the track and pinion, then re-seat the mech and do the bolts up. Continue until the two mechs are in synch. with one another and effectively mirror images and ensure the synch shaft is rotated fully anti-clockwise until it locks against the ends of the toothed tracks.

[[Image:vvcrebuild-step7.jpg]]

If the cams are installed correctly the lobs will be in these positions 

[[Image:vvcrebuild-step8.jpg]]

Once the cam ladder is on the head you can check the timing marks, with everything lined up you should be able to see a semi-circle in the 6mm hole in the cam carrier like this 

Front cam -

[[Image:Headbuild-vvctimingrear.jpg]]

Rear cam –

[[Image:Headbuild-vvctimingfront.jpg]]