The most tricky part I found was getting the exhaust manifolds clear of the heads to get them off, as the vehicle should ideally be jacked up to access the exhaust flange bolts on the underside. Not having chassis stands available, I unbolted it at the cat and slid both manifolds back as one piece. This has to be done as the manifolds restrict access to the head bolts.
I found the engine much simpler than the 4 cylinder over-head cam units I am used to working on, but the work is more heavy. I am very sore in the muscles still. The best thing about push-rod engines is the fact that the cam timing does not need to be reset when the head is replaced.
Upon removing the head, I was presented with the problem straight away. It was a cracked exhaust valve on #3 cylinder, with 2 cracks and the face warped so it wasn't sealing properly, although just enough to get ignition at wide open throttle.
The car fired up first time, and now idles much more smoothly, on all cylinders. I am going to build another of these engines over the next year with as many bolt-on goodies as I can get my hands on, but hopefully this one will last a year or so now. All other parts appeared to be in good condition. I'm not sure what caused the cracked valve, but it may have been due to the fact that when I got the car, the thermo fan was not activating so it may have been because of excessive heat.
It still idles a little rough, and takes a few seconds to start, and I feel it is fuel system related, so I will be performing a preassure test, and getting the injectors cleaned as I have heard that leaky injectors or a faulty fuel preassure regulator can cause this problem.
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