Pertronix Advance

[Hotcorner]

Can someone help me with a question for a Pertronix distributor? With a 350 with an RV cam, where should I start as far as springs and advance limiters? Should I lock out mechanical advance and rely on vacuum advance?

[geezer#99]

It depends on your set up.
A stock versus modified thing.
Stock motor might like a lazy timing curve and a modded motor might like something more aggressive.
What motor, cam, heads, intake, carb, trans, rear gear ratio all play a part.
How is yours set up?

[Hotcorner]

Originally Posted by geezer#99

It depends on your set up.
A stock versus modified thing.
Stock motor might like a lazy timing curve and a modded motor might like something more aggressive.
What motor, cam, heads, intake, carb, trans, rear gear ratio all play a part.
How is yours set up?

Stock motor with Edelbrock intake and carb. Believe it’s an RV cam. SM465 trans. 3:73 gears an 33” tires. Loves to pull from low RPMS

[geezer#99]

What’s your initial timing set at?
That’s the best place to start.

[Hotcorner]

Originally Posted by geezer#99

What’s your initial timing set at?
That’s the best place to start.

It likes 13 deg btdc

[geezer#99]

Is your pertronix completely adjustable?

Usually you want total timing (mechanical+initial) to be near 32 degrees all in by 3200 rpm.
With your 13 you’ll want about 20 mechanical.

[Hotcorner]

Originally Posted by geezer#99

Is your pertronix completely adjustable?

Usually you want total timing (mechanical+initial) to be near 32 degrees all in by 3200 rpm.
With your 13 you’ll want about 20 mechanical.

Yes. Different springs and limiters came with it.

[Wrenchbender Ret]

Do not block off the mechanical advance.
George

[Hotcorner]

Originally Posted by Wrenchbender Ret

Do not block off the mechanical advance.
George

Roger.

[geezer#99]

Did you get charts with it to tell you what springs etc to use for desired settings.

You’ll likely want it to be fairly lazy to begin with.
You’ll need to experiment to see what your motor likes.

I’ve got a motors manual here with distributor specs.
Would you have the original distributor with part number.

[Rich72C10]

may want to take a look at my thread (page 3), I put my all in at 25K with the springs that are included.

https://67-72chevytrucks.com/vboard/...=818178&page=3

My Truck, from post1

SBC 350 Rebuilt less than 1k on engine at this posting.
TH350 Rebuilt at same time as engine.
307 Gears
Power Brakes and A/C (off during all timing checks)
12° Initial timing
30° ~3500 Max Mechanical (by offsetting light ° button to read 0 on the timing mark)
45° ~3500 Max Vacuum (by offsetting light to read 0 on the timing mark)
17 hg Vacuum @idle
Park/Neutral Idle 650
Tires 275 60 15
60 MPH = ~2500 RPMs