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Triumph Repair/Mark II timing gear/ chain align.


I am nearing the end of a five restoration on this little stinker. Fresh new engine will not start. After reading your excellent article on Spitfire cam timing, I saw where cam is out of time. #4 cyl. is on tdc, compression, and tappets adjusted to .080. So I then removed timing cover, and sure enough, there was a crank gear, cam gear, and a chain. neither my engine builder or myself are familiar with set up, so please advise me as what to do. I am considering learning to cuss in British. Article is very well written but left me lost as to properly fitting cam gear

Thank You

William (So. California)

Hi William,

The Spitfire cam timing is unique and very good, but not easy if you don't know the proceedure.
First with the sprockets and chain off, set the crankshaft so that #1 & #4 are exactly TDC.
Then set the valve clearance EXACTLY the same of valves #7 & #8. (I use .050") (this gets the cam off of the transission ramps and on the lifting section of the cam) (This only applies to a stock cam.) If you have modified cam you then MUST use the procedure recomended by the cam manufacture.
Now turn the cam so #7 & #8 valves are in their "rocking position" (between the exhaust stroke and the intake stroke)
Now look at the chain and sprockets to see if the sprockes have been marked. If they were marked they will have marks near the teeth to line up with each other and an additional mark near one of the four mounting holes. If not it does not matter.
Put the chain on the sprockets and see if you can get two of the bolt holes it line up WITHOUT MOVING THE CAM OR CRANKSHAFT. There are 4 mounting holes in the cam sprocket but only two bolt holes in the cam. (be sure to push the slack out of the chain on the chain tensioner side when checking the cam timing)
If the holes don't exactly line up you have a half tooth adjustment by rotating the cam sprocket 90 degrees in the chain and use the other pair of mounting holes. If it still don't line up correctly remove the cam sprocket from the chain and flip the sprocket over and try both sets of mounting holes on the reverse side of the sprocket. This gives you 1/4 tooth adjustment. (each time be sure to push the slack out of the chain on the tensioner side of the chain)

Let me know,


Triumph Repair

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Howard M. Fitzcharles III


Triumph TR-4 up & Spitfire, and Engine theory


Dealership line mechanic on MG, Triumph, Jaguar for 15 years, Instructor in commercial mechanics school 2 yr. Product information manager for piston and valve manufacture, Instructor & hotline answer man for import car parts importer 15 yrs.

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