So
there were two problems: the oil pressure seemed to drop a bit sometimes and
there was a misfire. I felt downbeat about it. After all this work I had
problems on my hands. I just wanted to be driving it with a clear mind. So I
made a plan. A plan helps overcome the fear. My ideas for the misfire were:
cam timing, inlet manifold leak, leads. I went down the local scrap yard and
obtained a standard cam pulley. Maybe my vernier pulley was confusing the
issue. I set to fitting the pulley. I took the spark plugs out to make
turning the engine over easier. Aha! Plug no 3 had a bent electrode! I felt
a big rush of excitement at this. The plug would definitely not fire right.
Within a few minutes I had the engine back together and went out for a test.
Wahey! Smooth as ever.After taking some advice on the MIG bulletin boards I was more relaxed about the oil pressure situation. All the same, I wanted max pressure all the time above 2000rpm like I'd had before. I decided to monitor the situation and maybe remove the oil cooler. I did wonder if this had an air lock in it or something. The oil pressure only seemed to drop when the temperature rose. I ordered a standard spigot from Vauxhall so that I could do away with the oil cooler sandwich plate.
Later in the day I decided to check the oil pressure relief valve. I found it quite hard to get the valve out. There was some minor clag sticking it in place a bit. This was good news. A slightly sticking valve would make the pressure a bit variable. I cleaned it up and refitted it. It was much smoother. On the road the engine made rock hard pressure from 2000rpm upwards. I was very chuffed by this. I could finally relax and get on with the job of running the engine in.
I
took one the bearing caps apart on the old block. The bearing surfaces were
in very good condition. This is a tribute to the benefits of regular oil
changes. I changed the oil about every other month, or 2000miles.