Valve Timing

Hello,

i try to get my ABC running after the engine overhaul, unfortunately i was not able to check the timing and ignition before the repair, so i am missing this data.
Are there adjustment values for the mentioned points ?

Greeting

Wolfgang

hi wolfgang there should be a dot on the crankshaft pinion if not it is at the keyway position then line the 2 dots up on the middle cam with this set the ignition timimg to top dead centre ignition fully retarded try a bit of petrol down the inlet manifold screws it may need it after being redundant for a while and try it. i am assuming the carb is clean and the magneto good ps it is no. 1 cylinder left hand one you set the timing at

Hi Wolfgang

Attached is a picture of my engine crank pinion and cam gear. My machine has a small dot on the cam wheel which lines up with the key way on the crank pinion. The dot doesn't quite line up and is one tooth out, but fortunately there is a scratch on the cam wheel which does line up perfectly. I guess a previous owner had the same trouble the alignment!

Any way hope this helps?

Phil

hi phil it should have 2 distinct dot each side of the root of the tooth that it should line up with but people have had 100 years to mess with them are there any dots on the other side it may have been reriveted ? does it run ok if unsure put a timing disc on and check it that way the racers did run 1 tooth advanced anyway

hi again another problem could be if some part of the cam has broken then repaired and not put back in the correct position ie a hole or 2 out on the pcd

Hi Keith

Just had a look at my cam and I can confirm that I only have the one dot. No marks on the reverse other than lots of Sopwith inspector stamps.

The tooth gap just to the left of the marked tooth has a scratch mark and so I guess a previous owner marked it for ease of timing. I am going to my timing disk.

Phil