Guide For Cam Timing

[16v205 9]

Hi

 

Is there a guide anywhere online I can have a look at to help setup the cams on a gti-6 engine?

 

Ive just bought a pair of Catcams 4903108 cams. The pulleys on the gti-6 are verniers so exact timing has been lost now ive seperated the pulleys off the original cams.

 

How do I go about finding the correct timing again with a DTI gauge?

 

Cheers

Rich

[Sandy 191]

First job (before the cams are fitted is safest) is to get No.1 piston at TDC, so with the spark plug removed, drop a fairly long screwdriver (gently) down the hole so it touches the top of the piston, now turn the crank by hand until the screwdriver rises to its highest point. Set up the dial gauge on top of the screwdriver (or something shorter), to find the precise point at which the piston is highest. This is TDC. (There are more accurate ways, but this is sufficient).

 

Now install the cams.... with the inlet cam No.1 lobes pointing to the front of the car and down slightly (this will give you roughly the right timing and reduce the chance of valave-piston contact), the exhaust cam No.1 lobes pointing to the rear of the car and down. Torque down the caps etc.

 

Fit the pulleys and set the dial gauge up on one of the No.1 inlet tappets (tricky, but as near vertical as possible). Turn the cam anti-clock until the gauge reads no movement, then zero it. Now turn the cam clockwise until it reads the specified lift at TDC (2.0mm on this one). Hopefully the cam will stay put at that angle, this is zero degrees timing. Now repeat the process on a No.1 exhaust tappet, but turn the cam clockwise first to get no lift, then anti clockwise to get the specified lift (1.55mm on this one). Fit and tension the timing belt and mark which hole on each cam pulley corresponds to 0 degrees.

 

Turn the engine over twice and recheck the lift at TDC, it'll be harder to keep your head round it as you move the dial gauge about, but if unsure, have a cuppa and come back!

 

There you go.

[16v205 9]

Thanks very much for that Much appreciated.

 

Rich

[jonD6B 0]

Follow Sandy's advice but try and reduce the movement of the screwdriver/guide as much as possible as you're only talking thou's on a D.T.I. and obviously have it set up properly after getting somewhere near too.