009 Distributor

Run the engine on a dyno. Start with an out-of-the box distributor (ANY Distributor, 009 will do too). Hook up a mixture gauge. Hook up a head temp sensor & gauge (Or two) Hook up and calibrate a knock sensor. (!!!!!)

Now plot the power curve in a matrix, and add another curve that shows the advance at the same rpms you plotted power output at.

Now start giving the engine more advance at each measured rpm point, to see how much advance it can take before pinging. This gives you your critical curve. You can do this simply by turning the distributor and not tweak it yet. Then do the run again to find the best power output, not the biggest advance. You could also do this at the same time when looking for biggest safe advance actually. (To save your engine one stressful dyno run). Just twist the distributor so that you get the most power at each measured rpm, making sure it's just below knocking/pinging point. You get your "desired" curve as a result. This is when you define your safety margin too. (Can you guarantee you will always get the same grade fuel at the LEAST? How about altitude? Heat?).

Once you've completed the run, you will have the optimal ignition advance curve mapped out for the engine, but still no changes are made to the distributor. Time to TWEAK.

Tweaking:

Basically you have three things to adjust. Advance rate, maximum advance and advance points at different rpms.. you can get progressive advance by adding an extra spring (like the stock SVDA has). If you were adventurous enough, you could get several progression stages my changing the mechanical parts of the centrifugal advance mechanism... Oh but now I'm getting carried away. :) Let's assume you didn't want to go in too deep. Just play with the spring pre-tension, and stiffness. You can experiment with different springs. If you don't want to add an extra spring that would kick in later, (like the stock SVDA), you could maybe find a progressive spring to replace the original with. or hey, make your own... :) When you're done with the spring, Then play with the travel stop tabs to get the total amount of advance you need. You will soon learn that the advance curve of the 009 cannot easily be altered to match the "optimal" curve you mapped on the dyno when you twisted the distributor body at each rpm point to achieve "cheated" optimum. The curve may fall short somewhere, while it might give too much advance (pinging) at another part of the rpm range. You need to find an acceptable compromise, a curve that never crosses the critical (pinging) limit, but follows the maximum power line as close as possible. When all this is said and done, no more power can be extracted from the engine, if you did all the tricks you could to the distributor.

To save the engine from repeated dyno runs, you can just plot the engine power and optimum advance on one chart, (along with the critical curve), then take the distributor out and tweak it on a distributor bench instead. Those have an electric motor that drives the distributor, and imitates the engine. You can run the distributor on the dizzy bench all day long, and not risk your engine. Just plotting the curve on the chart, trying to match the curve you plotted on the engine dyno when you started.

Naturally, all of this would be only half of the work if you didn't bother to fine tune the carburator (or injection) too, to gain more power. That's where the "normal" engine dyno tuning comes in. It's a whole lot more work but I'd rather not go there in this article.

OR YOU COULD ALWAYS JUST BUY A 009 DISTRIBUTOR AND BOLT IT ON, SET IT AT

-That's what 99.99% of 009 buyers do, anyway. LOL (It would work... reasonably well)

It's late and I'm tired, if I made any mistakes there, I hope someone else would point them out.

Jan

I wish I friggin knew. When my big engine was built it came with a well balanced, well tuned 009 which I interepret as "okay". But WTF! When a guy spends $11,000 on an engine, why should he get a 009? Maybe, just maybe because it is "adequate". I didn't pay for Adequate! But maybe I got it.

Is that all sufficiently ambiguous to cast aspersions and keep my ass out of a jam? I think not. Let it be.

So, that said, run it and be happy. Or not. WTF.

Please don't refer to your ass and "jam" in the same sentence again. Also you misspelled "aspirations." Thank you, and of course I'm GLAD I COULD HELP!

Hahahahaha

jan