I have read through a few of the older posts about recurving the slant distributor to figure out what the stock centrifigal advance was supposed to be, and I think it is 12. Now for the dumb question: I assume this is at the crank. Is that right? You know what they say about the word Assume?

Sam

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Specs are at the distributor..........

Double for crank

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

So does the centrifigal advance add 24 degrees at the crank? That seems like alot. One of the threads I was looking at was one you participated in heavily.

Sam

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Sam,

The centrifugal advance depends upon the year and model the engine was used in. 18-26 degrees at the crank (1/2 that at the distributor) seem to be common. Cars with late initial timing typically have more centrifugal advance.

Joshua

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Joshua

I see. I was trying to relate the old distributor advance to what I now have programed into the ECU. I was just trying to get a feel for how different the current map is from what was. The distributor I used was, to the best of my recollection, the same one that came in the original '69 engine.

Sam

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With the dizzy I am running at the moment, and no vacume advance, with the base timing set at 20* when I bring the RPM up the timing will advance from the 20* upto 46* by 2600rpm. So it advances 26* from the centrifugal advance. This is the dizzy that came factory in my 68 Cuda, but with light weight springs installed. The springs dont let it advance anymore than it should, just quicker.


This setup works very good for, but it is to much advance for power at WOT. Soon I will limit the amount of advance so it will only advance to 28* total. But I am going to set the vacume advance up so it will bring it back up to the 46* that I have now when at light cruise & part throttle. But when WOT is reached it should loose the vacume and fall back to the 28* that the machanical allows it to reach now which is good for part throttle on my stock engine. With the way the dizzy is set now if I use the vacume advance it reaches over 55* timing which is to much, it doesnt miss or anything but slight detination does happen at light throttle.


Jess

For those of you that want to "lock out" the distributor by simpley removing the springs- it don't work so well. Timing is unstable under 1500 rpm, at least on mine. I would have thought as soon as the engine started it would go to full advance. It does but it bouces back 10-15* when idling. You can even see it in the tach. Its suddenly moves 300 -400 rpm with not engine speed change. Of couse the engine speed changes after the movement because the timing just changed.

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67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir