Update time! Fitting the head and timing the new cams in:
I've already got the cams installed with the vernier pulleys. 10.5mm lift over the standard 9.5mm:
Easiest way to time the cams correctly is by reference to lift at Top Dead Centre. Dave Andrews' k-series engine page has a very useful step by step guide on how to do this.
First, you need identify when cyl 1 and 4 are at TDC. There are a number of ways to do this. Since I had the head off, I just did it by eye. It took a lot of patience as there is a dwell point right at the top where the piston hardly moves. If the head is on, you could either rig up a dial gauge with a long probe down through the spark plug hole, or use a long bolt (like a head bolt) down through the plug hole and do it by eye. I made up a pointer for easy reference:
Before the head went on, I set the bottom end to exactly 90 degrees Before Top Dead Centre:
I then used the timing marks from the stock pulleys for 90BTDC to make equivalent marks on the vernier pulleys, so the timing is as close to correct as possible. Head on and cambelt refitted:
A quick point on head bolts. It is possible for the bolts to be too long and foul the sump. This obviously affects the clamping on the head gasket and it's believed to be one of the contributing causes of head gasket failure on the k-series, expecially if using cheaper aftermarket bolts.
As before, I'm using the 5-layer n-series gasket but this time I'm using it with the supplied higher grade 10.9 bolts (which require a modified tightening procedure of 20nm + 180° + 135°). These bolts were very slightly longer than the old ones I took out (which being used stretch bolts had probably stretched slightly anyway). To be safe, I shaved a couple of mm from the tip of each bolt:
Rigging up a dial Gauge using brackets I had made up a while back to Dave Andrews design. Used some 2.4mm tig wire screwed into the tip of the gauge and bent to shape.
Very tricky getting the gauge in the right place with the gauge tip on the lifter but not fouling the camshaft:
Engine set back to TDC. Then loosened the clamp bolts on the pulley and adjusted the cam to give the correct lift at TDC as specified in the spec sheet. On the inlet, this is 1.4mm:
Actually wasn't that simple at all! Every time you clamp up the vernier clamp bolts and turn the engine over a couple of times it changed! It took at least 5 iterations to get it right. Got there in the end though!
One last turn over by hand to make sure nothing collides. I then spent the next few hours putting everything back together and refilling fluids.
Crunch time. One last check over everything. Unplug injectors for a test turnover. Turn the key and...
I rigged up a spare with enough charge to turn over and check I have oil pressure. All good.
Gave the battery a quick charge. Injectors plugged back in and ready to go.
Fired right up on the key despite this map being way out for these cams. There then followed a very nervous 20 minutes running at 2k - 2.5krpm to bed the cams in. During this time I checked for leaks and generally panicked and worried at every little noise. The top end was noisier than expected. Part of this I think is down to the low duration/high lift combo of these cams resulting in a high ramp up. A lot of it I think is down to a leaking exhaust manifold gasket. Video to follow...