Triumph Repair: Spitfire 1174 Valve Timing, position rock, bolt holes

Question
I have a new cam sprocket with no timing marks on it, nor is there a mark on the crank sprocket. What is the procedure for setting up the valve timing?

Answer
Hi Robert,
The Spitfire cam sprocket has 4 holes but only 2 bolts. The holes are slightly off set from each other and if you turn the sprocket over that gives you 4 different settings. Set the crank so 1 & 4 are exactly TDC. Set #7 & 8 valve adjustment at .080" and set the came so that #7 & 8 valve are in their "rocking" position. Rock the cam back and forth until the clearance of both valves are exactly the same no matter what that clearance is. Then slide the crank sprocket in place and the chain on and put the cam sprocket in the chain and check to see that two of the bolt holes line up. DON'T move the crank nor the cam. If the holes don't line up then take the sprocket out of the chain and rotate it 90 deg. and try again and if it don't line up remove the sprocket and flip the sprocket over and try again. If it still don't fit rotate 90 deg. One of the four possibles will fit. Then check the ignition timing as you could get that out of whack setting the cam timing.
Howard