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Timing spec and curve

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caseyjones955

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What is an ideal timing spec (and rpm)and timing curve for a 79 1500 Midget w/the Weber and header system? The weber does not use the vac advance so its operating on cent. advance only. All emissions systems have been removed from the car.

Also, what would be some noteworthy symptoms of a worn timing chain? I could find nothing on this in search.

Thank you
 
you should be able to hear it rattle.
 
No rattle under the timing cover. I am going down the list of things that could be causing a chronic vibration/missfire off idle. Im stumped and the guy at motor service is stumped also.

I was previously sure it was the carb/fuel management, I replaced a defective diaphragm and the problem seemed to go away. I posted happy results only to see the symptom return on the next drive.

I decided that the ZS sucked and I knew I wanted to RR it anyway so I installed a Weber 32/36 conversion kit. The results are most pleasing. Power, responsivness, economy... what a difference, I can actually drive this car now. I CAN go up hills without muttering "I think I can, I think I can, I think I can"

I would like to fine tune and determine the need (or lack of) for an aftermarket dizzy. The timing chain question was more for this 1500-2000rpm ish vibration that wont stop haunting me. Im goig to tune it and use it as a daily driver while I continue looking for this elusive missifre.
 
Casey, try 28 ~30 degrees total advance at 2500 RPM. Without the vacuum advance, I would expect a small glitch off idle.
One other symptom of a bad chain or tensioner is the timing mark bouncing around when checking it. The tensioner on a 1500 is just a spring steel band, that rubs against the chain. They wear out, and conveniently deposit metal particles in the oil system.
Check with Jeff at Advanced Distributors for better information.

https://www.advanceddistributors.com

Jeff
 
""""""""""""""""decided that the ZS sucked and I knew I wanted to RR it anyway so I installed a Weber 32/36 conversion kit. """"""'

Yes about 30 degrees total.

You can check for excess chain stretch by watching a valve event on one valve while rotating the motor backward...stop....and then forward. but you might have no basis of comparison.

""""""Casey, try 28 ~30 degrees total advance at 2500 RPM. Without the vacuum advance, I would expect a small glitch off idle. """"""""

The fix for this is to run more initial lead and shorten the curve so you still have 30* total at the crank.
 
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