Having recently won a nice snap-on timing light on ebay I decided to put it to good use and see what my timing actually was, up until now I have done it by ear and backed off a little from pinking. I was rather surprised to find that it was 26deg advanced at 2000rpm (with vac disconnected) and 15deg at idle). Now the book says it should have been about 16 degrees. Since I had changed the timing chain last year I guessed that the most likley cause was the chain was one tooth out (40 teeth so one tooth = 9deg).
Last night I stripped it down and took off the timing cover and I was quite surprised to see that the 'P' mark on the camshaft was 180deg out (ie from the 11o'clock bolt hole). The crankshaft was at TDC according to the pulley (woodruff key on crank pointing to 12o'clock as well) and the dizzy was point at no1 lead (which peering into the cr from the drivers side was about 1'oclock).
Now when I changed the timing chain I took great care not to move the camshaft and crank until I had the new chain on (I have to confess I left rad on) and assumed that every thing could just be slipped back on, I might have been 1 tooth out but not 180deg. I had to readjust the dizzy a small amount (I assumed this was necessary because the old chain had probably stretched a little). but the car appeared to run fine and I have done hundreds miles since. The starting was always a little sluggish (needed a bit of choke), and sometimes I felt that it was a bit hesitant but no major worries.
Anyhow last night I spun the camshaft a few times trying to work out why it was 180deg out, but each time as the dizzy approached sparking on the no1 lead, the 'P'mark wasabout 180deg. Since I couldn't work out what was going on I just readjusted the chain by one tooth (it was out, if you ignored the 180deg out prob) and then reassembled. After adjusting the dizzy I got her started but the timing reads about 16deg advanced at idle.
This morning I started her from cold and got her running with no choke (previosly this would have been impossible).
So the big question is why does it run with the c1am 80deg out, has the dizzy drive dog been rotated 180deg out in the past, I'm totally lost for ideas. I was not keen to just set the cam by the book coz it would have left the dizzy pointing at no4 lead at TDC.