The engine was due a cam belt change before it so inconsiderately punted me off the road and up a grass bank, so makes sense to do it while it's out. Cam cover off, and it's looking nice and clean for 48k in this car and 84k in a previous life.
(Avert your eyes now) Crankshaft locking tool.
Now, the cams on this engine are modified, which means they are ground from OEM cams or OEM blank castings. The alignment grooves cast into the cams are rendered inaccurate when they are reground with a different profile and, in any case, the clearances are much tighter due to the more aggressive profile, so accurate cam timing is vital. To that end, we must time the cams the hard way.
Firstly, we mount a protractor on the crank to measure the crank angle.
Then we use a DTI on number 1 piston to find the true top dead centre of the engine.
.. and align the protractor with a datum at TDC.
Then we use the DTI on the cam follower of one of no.1's valves to measure where (in this case) the valve is fully open, and read the angle from the protractor.
I tend to find the reading at maximum valve lift and then turn the engine clockwise through the cycle, taking a reading a few 100ths of a millimetre before and after the lift has peaked. Then calculate the mid point between the two angles and this should give an accurate indication of the cam timing. In this case we're looking for the intake valve to be fully open 110 degrees after TDC and the exhaust valve 114 degrees before TDC.
The cam pulleys have a vernier adjustment (scale just visible in the lower left) to allow small adjustments to easily be made.
It's a bit of a faff, but essential to get the best out of the cams.
Kevin