Found a good cast timing gear I need for my engine . It has 2 marks on the gear. One is a circle nd the other is a center punch mark . I am assuming the circle is correct.
Don't quote me 'cause I'm no expert by any means, but I'd say the circle is some kind of makers mark. I bet it's the punch you need to go by. Pretty sure that's what I've read here before.
I'm no expert either, but the circle is the factory timing mark. Dan
Would the punch mark be an advance setting like a 7.5 degree or similar? Oh by the way I'm certainly no expert, I keep hearing I need to pay attention, heck I don't even known him.
360/48=7.5 so I think 1 tooth would be 7.5 degrees there are 5 teeth between the marks so I think that would be slightly much to advance the engine.
Circle is the stock market
I have seen a lot like this one who ever worked on the engine in the past marked the gears with a punch marks and it's back in time
I bet if you had the crank gear it have circle and the punch mark as well
Set #1 to top dead center, turn the cam until both valves are closed and see what mark lines up.
I think Bobs explaination is correct and am going to set the timing with the circle . the crank gear is marked by very small ford inscription
I can understand a mechanic/handyman punching his own timing marks on the cam and crank gear before removing same, so they go back together in the correct relationship. if you have a similar punch mark on the crank gear, rotate the assembly and see if his marks also co-incide with the factory marks, those being the circle and script.
Allan from down under.
Do you not have another gear that you could compare it to?
It's been a while since I was inside an engine, but as I recall, when the timing marks are lined up, #1 is NOT at TDC.
Seems like when #1 is at TDC the timing mark is straight up? Maybe I'm wrong?
Hal- you are correct- the crank gear key is aligned with #1 rod throw and is at 12:00 when at TDC. The timing mark is aligned with the centerline of the crank gear tooth that has the timing mark on it. Because of the helix, this places the crank gear timing mark to the right of the keyway in the crank gear.
I googled Model T timing gear. It referred back to a post July 2010. It appears as though the correct mark is the o. Jim Patrick explained it well in that post.