QuestionQUESTION: hello Howard,
i have currently rebuilt my spitfire engine and have it all together and it sounds like its a tooth off and just wants to start but cant. i pulled the timing cover off and i have all the gears lined up with the marks. what would be the best thing to do with the timing? should i turn the cam or crank and how many degrees???? or if there's another thing to do that i may have missed? not too sure, thanks for your time.
nick
ANSWER: Hi Nick,
Did you set the cam timing as per the factory settings?
Tell me exactly how you set the timing.
You should NEVER change the cam timing from factory settings unless you have installed a racing cam and they will give you the specs.
Howard
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QUESTION: what i did was during the tear down i recorded where the timing gear was and the crank at top dead center compression. it literly sounds like im a tooth off.\r
nick
AnswerHi Rick,
The Spitfire cam timing can be set in 4 different positions between one tooth in either positions.
Here is the procedure, first set #4 piston at TDC of the compression stroke and adjust the valves #7 and #8 to .080". Then rotate the crankshaft one revolution so that #4 is at TDC EXACTLY of the exhaust stroke. Now check the valve clearance of #7 and #8 again. If the valve clearance is EXACTLY the same, the cam is timed correctly. If they are not the same, then the cam is out of time.
If they are not the same, remove the cam sprocket and you probably note that if you were to move it one tooth either way it still will not be correct. Triumph has provided for 4 different setting between one tooth. Here is how it is done.
Remove the cam sprocket and rotate the sprocket 90 degrees and use the other two mounting holes. Set the cam so that both valves have the EXACT same valve clearance (providing you have not moved the crank.) A dial indicator placed in the spark plug hole can tell you that you are at EXACTLY TDC. Then compare that with the ignition TDC mark on the front pulley to see if it is correct. (Be careful, because the dial indicator is not a good straight shot at the piston so it is easy to damage the rod on the dial indicator) You MUST be EXACT on every thing you do!!!
If moving to a half tooth change by using the other two mounting holes does still not get it EXACTLY correct remove the cam sprocket and flip it front to back and try each set of mounting holes which then give you a one forth of a tooth change.
Over the years I have had to correct many of these engines.
Once you have done this, it eliminates the cam timing as a fault to any running condition.
Let me know.
Howard
