I have searched the site for other posts on markings on the flywheel and use for timing and setting valve lash

There are conflicting answers to whether to use the circle or triangle for setting valves (TDC)and timing ignition (BTDC... 5 degrees?)

with the flywheel turning clockwise the triangle comes into view first.. followed by the circle shortly after. Wouldn't this indicate the triangle is for timing (BTDC).. and the circle is TDC?

I timed the motor (62 261.. original flywheel) by vacuum and its shows with the timing light just before the triangle

Engine runs fine with this timing ...approx. 20" vacuum... smooth idle.. Im just curious as to what each mark is supposed to mean... any insight?

The general consensus is the circle is for timing.. which then brings the question... what is the triangle for?

Last edited by dirtball; 04/27/2015 4:40 PM.

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