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Total timing SBC 350

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Old Oct 7, 2023 | 06:56 PM
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Total timing SBC 350

I am new to timing a car and am trying to time my 350 SBC, I have put a proform hei tuneup kit on it with different weights and lighter advance springs. When I start the car the initial timing seems to be at about 12 degrees, When I rev it up to 3,000 the timing only comes up to about 22 degrees. From what I read a good number to be at is 10-14 initial and 32-36 total when you raise the rpms. What do I need to do to get my total up to 32? I have the lightest springs in it and its still only advancing to 22 at 3k rpm. Do I need to increase my initial to 20 so that my total will be at 32? Or should I put the medium springs in and see where im at?
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Old Oct 8, 2023 | 09:21 AM
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Car: 86 Trans Am WS6
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Re: Total timing SBC 350

the springs only control how fast the timing comes in and when they come fully in, not the total timing. the weights are what control the total advance of the curve
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Old Oct 8, 2023 | 10:57 AM
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Re: Total timing SBC 350

More specifically, the shape of the little "arms" of the weights that contact the cam thing on top of the dist, and the shape of the cam itself. Both of those features have a yyyyyuuuuuuuujjjjje variety and can be used as tuning tools.
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Old Oct 8, 2023 | 11:10 PM
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Re: Total timing SBC 350

With the lightest springs, could I already be into the advance weights at my idle 800 rpm? That might be why I only get like 10 degrees of mechanical advance instead of the usual 20? or is there something else I should be looking at to change my amount of mechanical advance
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Old Oct 9, 2023 | 08:53 AM
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Re: Total timing SBC 350

With the lightest springs, could I already be into the advance weights at my idle 800 rpm?
Yes. Especially if you are using the heaviest weights.

Eeeeezzzy enough to figure it out: do something to fix the weights in place (tie-wraps, fishing line, etc.) and see what happens.

Also, check the underside of your rotor, and make sure it's not interfering with the motion of the weights. More common than you might think. I've woke up SEVERAL engines over the years by putting nylon washers under the rotor at the screw holes.
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