Question, ready to install my distributor for the first time. Do I set balancer to 12° btdc(compression stroke) for initial timing or do I set it to 0° . Freshly built 383 with mini ram .

 

I would zero everything out, and install it that way.

 

You will undoubtedly have to advance it and while there's no harm in starting at zero, there's nothing to prevent you from starting from an advanced position. Depending on the dynamics of the engine, trying to start with 0 advance might prove difficult.

 

I would attempt to set it in an advanced position so that the engine is easier to start and stays running until you can set your base timing and your throttle position for your desired idle speed. Easiest way to find TDC to ensure you aren't 180° of cam rotation off is with a dual vacuum/pressure gauge. You can buy them pretty cheap at most automotive or tool stores. Mine was $13 at Harbor Freight, the harbor freight version you would just buy a spark plug adapter or make an adapter .

 

Turn the crank by hand while watching the valves. Specifically, the #1 intake. As you turn the crank, watch for it to open, then close fully. The next time the timing mark aligns is the TDC instance where it fires. (the other instance of TDC being, where the exh is just closing and the int is just opening)

You can check your timing mark for accuracy, not down to the last degree, but easily within 10° or so: watch the #6 valves while turning the crank by hand, look for the exh closing / int opening point for #6 like the one described above, the #1 firing instance of #1 & #6 TDC is always very close to that. Meaning, the timing mark should be pretty close to lining up, as that happens. If you find that point, and the mark lines up, then the mark is at least useable, even if not verified to be dead on *****.

If the mark is farkled, as is quite common, then find the point where the #1 exh is closing and the #1 int is opening, by the same amount. (each should be just a very little bit open) From there, turn the crank 15/16 of a turn (3 90° increments, then ¾ of a 4th 90° increment) to set it to a good startup advance point.

Note that with the sprockets "dot to dot", as one would generally assemble them while building a motor, that point is #6 firing, NOT #1 firing. #1 & #6 always come to TDC together; they alternate firing on those instances. "Dot to dot" is #6 firing. Exactly one full crank rotation from there will put both dots at 12:00 (crank dot will return to 12:00, and cam will turn ½ rotation, moving its dot from 6:00 to 12:00), and that puts it at the instance of #1 TDC that occurs immediately after #1 firing.

 

Thanks for the help!

 

It's always nice to have the timing very close when first firing up the engine so you're not fiddling with the timing just to get it started.

Basically as mentioned above
Remove valve cover to watch the #1 rocker arms or you can just remove the #1 spark plug and put some paper towel in the hole.
Baring the engine over by hand, watch the rockers until both close or the paper towel gets blown out of the spark plug hole. This will be TDC #1
Check where the timing mark is lined up. It should be very close to TDC. Keep baring the engine over until you have your base timing set (12 degrees if you want)
Remove the distributor cap and move the rotor so it's pointing roughly at the #1 spark plug. The rotor will turn slightly when dropped into the engine. You'll also need a long flat blade screwdriver to turn the oil pump drive so the distributor will drop into place.
Once the distributor is dropped in and the rotor is pointing at the #1 plug wire, rotate the distributor until the magnetic pickup points line up. The rotor may need to be removed to see them.
Clamp down the distributor, put the cap and wires on. Timing is now close enough that the engine should fire right up.

Correct base timing always depends on the cam grind. Where the engine likes full advance depends on a lot of other things and should be changed with a recurve/reprogram etc, not by changing the base timing.

10- to 12-degrees of initial timing when the duration of the camshaft is less than 220-degrees @ 0.050” of valve lift
14- to 16-degrees of initial timing with a camshaft duration of less than 240-degrees @ 0.050”
18- to 20-degrees of initial timing when the camshaft duration is less than 260-degrees @ 0.050” of valve lift.
More than 260 degrees of duration is a race cam.

 

[QUOTE=Vito b;6296627]Thanks for the help!


[/QU



OTE]

Very nice motor, you will like this set up. The 383 is a torque monster, so you can get away with a manifold that like high revs, best of both worlds.... This is a small block chevy, zero everything and as long as your balancer is accurate, you will have no trouble finding the sweet spot.