Distributor Retards Itself

[LARRY70GS]

Timing was checked yesterday after getting a new timing light and it's at 32*... feels great though! Going to redo the total timing when it isnt storming now that I know this new light actually works. But 32* though.... does that indicate something is bad timing mechanism wise? Also for the quadrajet is there a specific quadrajet model I should get or just anything for 70s Buick 350s?

That's 32* maximum timing WITHOUT vacuum advance?

You need the correct Quadrajet, or one built to the correct calibration for your Stock? 1971 Buick 350. That would be a 7041544.

This is the Quadrajet guy we use at V8buick.com,

Everyday Performance Rebuilt Rochester Quadrajet Carburetor Positraction Axle Store

From bone stock to street or sport, Everyday Performance can help you bring your cruiser or daily driven muscle to life

everyday-performance.com

You CANNOT just buy any Quadrajet and expect it to run right. They were all calibrated for the engine they were for.

 

[Jackhammer0312]

That's 32* maximum timing WITHOUT vacuum advance?

You need the correct Quadrajet, or one built to the correct calibration for your Stock? 1971 Buick 350. That would be a 7041544.

This is the Quadrajet guy we use at V8buick.com,

Everyday Performance Rebuilt Rochester Quadrajet Carburetor Positraction Axle Store

From bone stock to street or sport, Everyday Performance can help you bring your cruiser or daily driven muscle to life

everyday-performance.com

You CANNOT just buy any Quadrajet and expect it to run right. They were all calibrated for the engine they were for.

Thanks, will check that out. Also 32* initial, and yes I did the total timing with no vacuum and put it at 34* with all timing in. Had to adjust the distributor a hair retarded after I test drove it, but it feels awesome now. Just worried about the initial showing so far BTDC. Maybe this means the balancer was infact wrong and I was wrong when I checked it? Idk.

 

[MelsRegal]

Thanks, will check that out. Also 32* initial, and yes I did the total timing with no vacuum and put it at 34* with all timing in. Had to adjust the distributor a hair retarded after I test drove it, but it feels awesome now. Just worried about the initial showing so far BTDC. Maybe this means the balancer was infact wrong and I was wrong when I checked it? Idk.

That is not being done correctly. You need a Mr. Gasket 928G spring kit and a DIAL back timing light. You are attempting to set total mechanical advance at about 3K rpm to about 36 degrees.
You do not set initial timing to 32 degrees. If done correctly with 36 at 3k rpm you will end up with less than 20 at idle.
There is a possibility your damper outer ring has slipped and you are getting an incorrect reading.

 

[Jackhammer0312]

That is not being done correctly. You need a Mr. Gasket 928G spring kit and a DIAL back timing light. You are attempting to set total mechanical advance at about 3K rpm to about 36 degrees.
You do not set initial timing to 32 degrees. If done correctly with 36 at 3k rpm you will end up with less than 20 at idle.
There is a possibility your damper outer ring has slipped and you are getting an incorrect reading.

The pertronix distributor came with a spring kit and all the timing came in around 2100rpm with the lightest springs. I followed the guide and made the mark 1 3/4" clockwise from the original punched-in timing marker on the balancer and used a digital timing light. Set the new mark on the balancer to 32*BTDC (the mark is 30* so put it on the 2* mark on the timing tab). Then adjusted the distributor slightly. This was all done with vacuum advance disconnected and plugged and engine to temp.

Is there a difference between the Dial Back and Digital timing lights? I thought they did the same thing but one was fancier than the other.

 

[Jackhammer0312]

Also just rechecked the timing, initial is still at 32*. Maybe the balancer has slipped?

 

[MelsRegal]

The pertronix distributor came with a spring kit and all the timing came in around 2100rpm with the lightest springs. I followed the guide and made the mark 1 3/4" clockwise from the original punched-in timing marker on the balancer and used a digital timing light. Set the new mark on the balancer to 32*BTDC (the mark is 30* so put it on the 2* mark on the timing tab). Then adjusted the distributor slightly. This was all done with vacuum advance disconnected and plugged and engine to temp.

Is there a difference between the Dial Back and Digital timing lights? I thought they did the same thing but one was fancier than the other.

So you need stiffer springs, the timing should be all in at 2,800 to 3,000 rpm.
Does your timing light have a dial or any buttons to preset the number you want?

 

[Jackhammer0312]

What do you mean by bad? The 32 was at what engine speed?
They don't make new Quadrajets other than junk from China, what do you have now?

By bad I meant like timing chain or super advance timing being very bad for the engine.

The engine currently has an Edelbrock 1407 on it and i was planning on getting a refurbished/rebuilt quadrajet, heard too many bad things about reman carburetors in general. Gonna take a quick look at the site posted earlier.

 

[Jackhammer0312]

So you need stiffer springs, the timing should be all in at 2,800 to 3,000 rpm.
Does your timing light have a dial or any buttons to preset the number you want?

Ah okay. It was running a bit weird with the lightest springs on but I swapped one out with a heavier one and it pretty much got rid of the weirdness. Gonna put in the other heavier spring then.

And yes the timing light has an adjustable advance light.

 

[Jackhammer0312]

Ah okay. It was running a bit weird with the lightest springs on but I swapped one out with a heavier one and it pretty much got rid of the weirdness. Gonna put in the other heavier spring then.

And yes the timing light has an adjustable advance light.

And by "a bit weird" I mean at certain rpms like slightly below cruising and lightly pushing on the throttle it would sound like the advance was coming in way too quick, which is when I pulled into a parking lot and changed one of the springs which pretty much made that go away.

 

[LARRY70GS]

No, that's not right. Maybe we aren't talking the same "ignition language". There are 3 components to ignition timing. Initial timing, mechanical advance, and vacuum advance. There are weights inside the distributor that move outward with centrifugal force against spring tension. Mechanical advance adds timing with increasing engine RPM. Distributors differ in the amount of mechanical advance built into them. It varies by part number, engine and year built. Vacuum advance is a load compensating ignition advance timing. The vacuum advance canister has a spring inside that opposes vacuum pull. Engines under light load cruise can benefit from additional advance for better gas mileage. At light load, engine vacuum is high, and vacuum advance is at maximum. At WOT, vacuum is at or near 0, so vacuum advance disappears when you mat the gas pedal. At any engine speed, ignition advance is the sum of initial advance + mechanical advance + vacuum advance.

Your initial timing cannot be 32*. That should be the total advance consisting of initial advance + the maximum amount of mechanical advance.

 

[LARRY70GS]

You need to read, and understand this post,

Power Timing your Buick V8

I thought I would try and compose this post to answer timing questions I see all the time on this BB. I see alot of questions about what initial...

www.v8buick.com

 

[MelsRegal]

By bad I meant like timing chain or super advance timing being very bad for the engine.

The engine currently has an Edelbrock 1407 on it and i was planning on getting a refurbished/rebuilt quadrajet, heard too many bad things about reman carburetors in general. Gonna take a quick look at the site posted earlier.

That much initial can only be a slipped outer ring on the damper.

 

[MelsRegal]

Try something. Disconnect vacuum to distributor. Remove all the springs and start the engine. Set the timing light to 36. Adjust the distributor so the mark on the spinning damper aligns with the zero mark on the timing tab. Reinstall a set of heavy springs and watch at what rpm the mark hits zero with the timing light still set to 36. If the rpm is over 3k use one heavy spring and one medium spring.

 

[Jackhammer0312]

Try something. Disconnect vacuum to distributor. Remove all the springs and start the engine. Set the timing light to 36. Adjust the distributor so the mark on the spinning damper aligns with the zero mark on the timing tab. Reinstall a set of heavy springs and watch at what rpm the mark hits zero with the timing light still set to 36. If the rpm is over 3k use one heavy spring and one medium spring.

Will definitely try that tomorrow, thanks!

 

[Jackhammer0312]

No, that's not right. Maybe we aren't talking the same "ignition language". There are 3 components to ignition timing. Initial timing, mechanical advance, and vacuum advance. There are weights inside the distributor that move outward with centrifugal force against spring tension. Mechanical advance adds timing with increasing engine RPM. Distributors differ in the amount of mechanical advance built into them. It varies by part number, engine and year built. Vacuum advance is a load compensating ignition advance timing. The vacuum advance canister has a spring inside that opposes vacuum pull. Engines under light load cruise can benefit from additional advance for better gas mileage. At light load, engine vacuum is high, and vacuum advance is at maximum. At WOT, vacuum is at or near 0, so vacuum advance disappears when you mat the gas pedal. At any engine speed, ignition advance is the sum of initial advance + mechanical advance + vacuum advance.

Your initial timing cannot be 32*. That should be the total advance consisting of initial advance + the maximum amount of mechanical advance.

I'm an idiot and just now realized I still had Vac Advance attached when i read the initial earlier today. Tomorrow when I get home I'll check it the right way and will read back over that guide.

This is cool stuff and I love how you can tweak and tune the ignition system and carb to your liking but what I don't like is having to know how to do it lol. I'll think I got it then I realize I was doing it wrong the whole time, but can't learn without failing first.

 

[LARRY70GS]

You should NOT be using the dial back advance features of the light until you understand how. Leave the setting at 0. Point the light at the tab with the vacuum advance disconnected. Make sure the tab is clean, and the balancer mark is highlighted with white paint. You should be able to read the timing at IDLE. The mark should appear somewhere on the tab (scale). That will be your initial timing. As you rev the engine higher, the mark should move higher and off the scale. That is the mechanical advance in action. Do that, and we will go from there.