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Timing 36 Total

2.8K views 11 replies 9 participants last post by  wshinn  
#1 ·
How do I go about setting my timing at 36 degree total? Also Do I set it with the vacuum advance connected or disconnected? I think I have an idea of how I am supposed to do it but I don't want to do it wrong.

Thanks
 
#3 ·
See the way I was told to set it, was to set my timing mark at 0 degrees, then bring the car to 3500 RPM and with the timing gun set at 36 degrees bring the mark back to 0 dgrees. Now the person how told me that (a stock car racer) forgot to mention(or forgot to remember) if I was to have the vacuum advance hooked up or not while doing this. I haven't tried it yet. Does this sound correct?
 
#6 ·
Bring it to 36 degrees total without the vacuum advance connected. At some point during WOT, the engine vacuum will stop pulling on the vacuum advance and all the timing will be from the mechanical advance. So, set the total mechanical advance to your desired set point of 36 degrees by using the procedure you have already described.
 
#8 ·
Nope. Vacuum advance is controlled by engine load via a manifold vacuum reference. Mechanical is constant and should be linear with engine rpm regardless of load. Under a high load and no manifold vacuum, the engine is working it's hardest and most susceptible to detonation. This is when you want no more than 36' timing. So you disconnect the vacuum advance and read timing.

Your engine can safely take up to 45 or even 50 degree's under the right circumstances. But the only one a rodder is concerned with is when the engine is mostly loaded and detonation prone. Vacuum advance isn't working at this point.
 
#12 ·
Canadian_78Z28 said:
How do I go about setting my timing at 36 degree total? Also Do I set it with the vacuum advance connected or disconnected? I think I have an idea of how I am supposed to do it but I don't want to do it wrong.

Thanks
The easiest way is to use an "advance" timing light. These have a dial on the timing light that you turn while "timing" your engine to determine what advance your engine is at. You'll need someone with experience to get you started, but here's what you can do... with the light hooked up and with the vacuum advance plugged on the distributor and with the engine "idling" you can move the dial on the advance timing light until the strobe is centered on the harmonic balancers "main" timing notch and "read the dial" to see how much "initial" timing you have. The trick is to zero the time mark on the "main" timing notch by turning the dial on the advance timing light.

Now it gets interesting. With the timing mark zeroed at idle (vacuum advance plugged/disconnected), you can slowly rev up your engine and, as you do, the mechanical advance of the distributor will start to come in and the timing mark will appear to move off (advance) of the main timing notch. As you continue revving your engine, you will probably have to adjust the dial on the advance timing light to keep the timing mark "centered" in main timing notch on balancer. However, at some point (between 2,000 to 4,000 rpm) the mechanical advance will be "full in". At the RPM the mechanical advance is full in, you will need to center the timing mark by adjusting the dial on the advance timing light. Once you have done this you will know what the total timing will be with full mechanical advance just by "reading" it off the dial on the advance timing light. Say it is 30 degrees and you want 36 total, then you just advance your timing 6 degrees (at idle if you like) and double check using the method previously described.

Wheww... hope that helps.

Will