Classic Thunderbird Club International
Gil's Garage
Gil Baumgartner
CTCI Authenticity Chairman
Locating Top Dead Center

The FoMoCo shop manuals address the location of the timing marks on passenger cars, but fail to mention our Thunderbirds. Basic information on timing marks can be found in the Tech Section under Ignition.

In very rare cases the timing marks cannot be found because the rear pulley has been damaged or repaired and the pulley timing marks need to be reinstalled. The following information addresses locating the correct position for the marks.

Photo # 1 shows the pulley marks and the engine at top dead center (TDC). This position can be reached by manually turning the engine until number one piston is at the top of its compression stroke verified with number one spark plug removed. At TDC the piston will be at the top of the cylinder and both the intake and exhaust valve will be closed. This is when the timing pointer should be aligned with the TDC mark.

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Photo # 2 shows both the intake and exhaust valves closed, verified by clearance between the rocker arms and the top of both valve stems.

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Photo # 3 shows the crank pulley with the bolt removed. The keyway for the crank pulley to crankshaft is at the 7 o’clock position. The keyway will be in this position when number one piston is at the top of its stroke. Be sure to confirm that there is valve clearance (photo 2). If there is clearance, you are at the top of the compression stroke. NOTE: The bolt need not be removed to verify this position unless the pulley timing marks are being reinstalled on a damaged or repaired pulley.

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Photo # 4 shows the positioning of the rotor when the engine is at Top Dead Center (TDC). When installing the distributor and all of the conditions are described above have been verified, the rotor should be pointing as shown. That is, the rotor should be pointing at the number one spark plug wire contact when the distributor cap is installed.

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Gil Baumgartner

Last modified: July 25 2016