Adjusting M42 Cam Timing

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Tools:

  • 11mm spanner
  • 10mm SMALL ratchet (I do mean small, you don't want to over torque the rocker cover bolts)


1. Strip off the leads and rocker cover

2. Mark the existing cam position with a centre punch one mark on the cam and one on the pulley)

3. Loosen the 11mm cam pulley bolts on the intake cam

4. Adjust cam - From standing at the driver's side (in the uk) pushing the cam away from you is advancing it. (That's clockwise from the front of the engine.

You might want to check roughly what it's set to before you mess about.

First set the engine to TDC (There's a very hard to see notch in the front trigger wheel that lines up with an arrow around the filter housing. There's also a little plug in the webbing of the bell-housing, just beneath the starter - this is where you can insert a pin (or well sized screw driver) to hold the engine at TDC - don't forget to remove this before trying to crank the car!!!

With the engine at TDC the two cyl. 1 cam lobes will be pointing in at each other (at roughly 1 or 2 o'clock from the front of the engine). At the cyl. 4 end of the cams the two flats that are face up should both have two dots. Put a flat edge across these two flats - when the flat edge meets perfectly with both flats on the cams - the timing is roughly stock.

Don't forget that messing around with this is just moving the power band - everything you gain lower down you loose up top and vice-versa.