carb timing.... Options

[bd1308]

is it 27 or 35 or some number in the middle?

i've seen 35 before.....

FI mark is 27 or 28degrees.....


which is it...help please.


b

[ArtechnikA]

QUOTE (bd1308 @ Oct 14 2005, 03:00 AM)

...static timing is done with the engine at TDC on cylinder one.

uh.... no....

static timing means to set the timing when the engine is not running. (that part you got right).
it is not done at TDC unless you want it static timed at 0 degrees advance... (you may wind up there, if your distributor doesn't have much total advance... but you don't want to start there.)

the spark happens when the points open. so you set the engine to where you want the spark to occur (5* BTDC is a good starting point - and that's 5* crankshaft, just like all timing specs... (with the possible exception of distributor advance curves, which is a topic for another day...))

then you rotate the distributor until the points *just* open at that point. if you have ignition, you can do this with a 12V test light connected between Terminal 1 and ground. when the points open, the light will light. (you can do this with the engine out of the car, using an ohmmeter or continuity tester.)

there is no magic. you want 6* initial (static) advance? you turn the engine so it's at 6* BDTC and rotate the dizzy to achieve that.

or you can time for total advance with the engine running and let static fall where it may. the problem with that method is you have to know how much dynamic advance is in the distributor. if you don't, one number is as good as the next.