timming marks
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Le Mans Master
Joined: Mar 2004
Posts: 7,493
Likes: 1,502
From: Little Rock AR
12 and 12 is #1 TDC Firing Position.
12 on the crank and 6 on the cam is #6 TDC Firing Position.
Either way #1 and #6 will both be at TDC at the same time. The camshaft position dictates where the distributor rotor needs to point when you drop the distributor in.
-Mark.
12 on the crank and 6 on the cam is #6 TDC Firing Position.
Either way #1 and #6 will both be at TDC at the same time. The camshaft position dictates where the distributor rotor needs to point when you drop the distributor in.
-Mark.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
I prefer 12 and 6 as well...seems more dead on when lining them up so you don't accidentally get a tooth off.
Either will work, but the builder has to be aware that once the engine is built he must rotate the engine to ensure that piston #1 is at TDC with both valves closed ready for combustion.
That goes for both, and might seem more confusing than it is. It's easier once you remember that the crank spins twice for every cam rotation.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
12 and 12 is #1 TDC Firing Position.
12 on the crank and 6 on the cam is #6 TDC Firing Position.
Either way #1 and #6 will both be at TDC at the same time. The camshaft position dictates where the distributor rotor needs to point when you drop the distributor in.
-Mark.
12 on the crank and 6 on the cam is #6 TDC Firing Position.
Either way #1 and #6 will both be at TDC at the same time. The camshaft position dictates where the distributor rotor needs to point when you drop the distributor in.
-Mark.
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Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
I prefer 12 and 6 as well...seems more dead on when lining them up so you don't accidentally get a tooth off.
Either will work, but the builder has to be aware that once the engine is built he must rotate the engine to ensure that piston #1 is at TDC with both valves closed ready for combustion.
That goes for both, and might seem more confusing than it is. It's easier once you remember that the crank spins twice for every cam rotation.
Either will work, but the builder has to be aware that once the engine is built he must rotate the engine to ensure that piston #1 is at TDC with both valves closed ready for combustion.
That goes for both, and might seem more confusing than it is. It's easier once you remember that the crank spins twice for every cam rotation.
