Question about timing a 69 RR 383

1967coronet said:

Lots of the older points style distributors have a 9.5 plate or a 19 degree limit.
I found one for mine, saves the welding and fileing .
As far as help when setting timing and total advance ect. It really helps having my better half running the throttle inside watching the tach.
My light is a dial back style , with her help and that light makes setting up a distributor pretty easy.

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hemidon1 said:

It wont matter--let that fall where it will--If you time the engine to 36 degrees with every thing hooked up it will start and run great--you can still change the initial timing by inserting an allen head key into the vaccum advance and dialing it up or down to give the initial timing you want--that is generally not need --dont forget to recheck the total if you change the vacc advance ---whats important is the total advance at 36 degrees to saturate the coil and so theres 9 degress of timing to light the cylinder-that takes up the 45 degrees for each cylinder--45 x 8 =360 degrees hope this helps--Hemidon

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hemidon1 said:

It wont matter--let that fall where it will--If you time the engine to 36 degrees with every thing hooked up it will start and run great--you can still change the initial timing by inserting an allen head key into the vaccum advance and dialing it up or down to give the initial timing you want--that is generally not need --dont forget to recheck the total if you change the vacc advance ---whats important is the total advance at 36 degrees to saturate the coil and so theres 9 degress of timing to light the cylinder-that takes up the 45 degrees for each cylinder--45 x 8 =360 degrees hope this helps--Hemidon

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65-440 said:

So not true... that's why we recurve distributors.....unless you get lucky and your engine just so happens to like whatever initial it has once you lock down total....not all distributors have the same mechanical advance!
To the OP, might I suggest.... first you need to find out how much mechanical advance is in your distributor... after that find out how much initial it likes/can take....lock that down.....next limit the amount of mechanical to get your all in at 36...

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hunt2elk said:

Curious why you need a friend to help set the timing? Run the throttle with your right hand and aim the light with your left.

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65-440 said:

So not true... that's why we recurve distributors.....unless you get lucky and your engine just so happens to like whatever initial it has once you lock down total....not all distributors have the same mechanical advance!
To the OP, might I suggest.... first you need to find out how much mechanical advance is in your distributor... after that find out how much initial it likes/can take....lock that down.....next limit the amount of mechanical to get your all in at 36...

Click to expand...

65-440 said:

So not true... that's why we recurve distributors.....unless you get lucky and your engine just so happens to like whatever initial it has once you lock down total....not all distributors have the same mechanical advance!
To the OP, might I suggest.... first you need to find out how much mechanical advance is in your distributor... after that find out how much initial it likes/can take....lock that down.....next limit the amount of mechanical to get your all in at 36...

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HALIFAXHOPS said:

Remember also that will not be 36 at the crank it is 36 added to wherever you set initial, jut easy numbers you set at 10 BTDC add 30 you have 20 ATDC on the crank

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HALIFAXHOPS said:

LOL new math. Where ever you set the initial you add the total mechanical to it. Starts as a negative number then past 0 and final result is positive if that makes sense. -10 +30 = 20

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HALIFAXHOPS said:

LOL new math. Where ever you set the initial you add the total mechanical to it. Starts as a negative number then past 0 and final result is positive if that makes sense.

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Don Frelier said:

Sorry but that is just incorrect. It's always negative you are going further BEFORE TDC as you add advance.
For example you start at -10 initial add 26 more centrifugal as you speed up the motor and advance to -36 Before Top Dead Center.

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mpro69rr said:

So I have -18 initial now, that means I would add another -18 to get -36 total?

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Don Frelier said:

Correct with the vacuum advance unplugged.
Under high vacuum conditions you can see even higher numbers like 45-50 degrees of advance that's when they can predetonate.

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HALIFAXHOPS said:

This video is pretty good around 5 min in is what I mean.

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