Stock Ignition System Tests will be as follows: ◦Test One: Stock Ignition System at 650 RPM with spark plugs gapped to .035
◦Test Two: Stock Ignition System at 1400 RPM with spark plugs gapped to .035
◦Test Three: Stock Ignition System at 2500 RPM with spark plugs gapped to .035
◦Test Four: Stock Ignition System at 650 RPM with spark plugs gapped to .040
◦Test Five: Stock Ignition System at 1400 RPM with spark plugs gapped to .040
◦Test Six: Stock Ignition System at 2500 RPM with spark plugs gapped to .040
Your stock ignition test is what I would do though I based on my limited knowledge.
And it will settle the oldtimer debate you mentioned where some hold the opinion later stovebolts ran better with the larger SP gap as the earlier stovebolts. Though did the oldtimers realize that when GM reduced the SP gap the point gap was reduced as well?
High Energy Ignition Tests will be as follows: ◦Test One: High Energy Ignition System at 650 RPM with spark plugs gapped to .045
◦Test Two: High Energy Ignition System at 1400 RPM with spark plugs gapped to .045
◦Test Three: High Energy Ignition System at 2500 RPM with spark plugs gapped to .045
◦Test Four: High Energy Ignition System at 650 RPM with spark plugs gapped to .050
◦Test Five: High Energy Ignition System at 1400 RPM with spark plugs gapped to .050
◦Test Six: High Energy Ignition System at 2500 RPM with spark plugs gapped to .050
For your HEI tests I would not do the .045 gap test. One it is to close to the .050 gap that you will not see enough change to make it worth your time.
Instead I would use the .035 stock SP gap setting. The reason is when doing a test you want to enter one variable at a time. Thus changing from points to HEI and then testing with stock SP gap the results will be only caused by one thing, the HEI.
I know money does not grow on trees. Though HEI has many reasons why it is better then points. Though HEI was designed to run with SP gaps of .060 to .080.
When people put HEI upgrades on pre HEI cars they also switched to large gap plugs. I feel those larger gaps is the main reason why they got a big increase in MPG.
So I still advocate for larger gap plugs though it is easy to advocate when it is not your own money being left on the parts counter. So I will endorse your tests with the .050 gaps.
