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Dizzy vs Timing chain?


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My first Z arrived last week, have been working my way through POs "repairs." So here is my question......

Early 260, with Mallory Unilite dizzy, MSD 6a and a Blaster coil installed by one of the previous owners. Car would not run above 35mph of course the tach isn't working. Timing at idle 750rpm, was 25 degrees and sounded like a big V8 with a wild cam. At 3000rpm, as high as it would go timing was 47 degrees. I tried to retard timing but the vacuum canister hit the out going water hoses from the thermostat.

I plugged advance tube and was able to get idle down to 20 degrees and full advance down to 40 engine will run to ~5000rpm and idles ok.

Also the plug wires seem to be off one hole (clockwise) in the dizzy.

Is the distributor installed incorrectly or is this a timing chain issue?

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This has absolutely nothing to do with your timing chain. The chain controls valve timing, i.e. the relationship of the camshaft to the crankshaft. The distributor controls spark timing, the relationship of the spark plug firing to crankshaft postition. Your distributor was installed incorrectly and the plug wires were routed to compensate. 40 degrees of spark advance is way too much (let alone 47! :ermm:), dial it down so that you have about 33-35 degrees of total advance.

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The distributor drive needs to be re-clocked. It is driven off of the crank and goes diagonally from the oil pump up to the distributor. You would need to drop the oil pump and rotate the shaft and plug it back in. It helps to have one guy on top and one underneath.

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I do not know about the UniLite with Vacuum Advance, which it sounds like you have from your description. I'll mention this just in case someone else here knows for sure.

The Mallory Unilite without vacuum advance comes with a "timing key" - which allows the owner to set the initial advance timing in the distributor {shown as degrees of Crankshaft Advance} from 20 to 28 Degrees.

Your problem may be there as well.

See: http://www.zhome.com/ZCMnL/tech/MalloryDist.htm

Set Up Instructions from Mallory are at the bottom of the page.


Carl B.

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Thanks Carl, I will check that out.....I am dreaming of running cottonwood pass in the Z

And thanks for the picture Brian....it will help when the wife is eyeballing while I am under the car, by the way my daughter spent a winter in Wanika teaching skiing.

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