John Lee's HEI Swap for an I6, (Measuring 30+ degrees on the Factory Tab!)

[Sharps40]

After installing the HEI on John Lee and finding it ran great at 10 degrees initial I decided to follow Mr. Langdons instructions and set it up as high as 18 degrees initial...but how to measure accurately on the factory tab?

And then I decided to measure the total advance at 3000 rpm but how to do that on the factory tab?

Read on.....

[Sharps40]

So, I started by setting initial timing up from 10 to 12 and eventually to an eyeball guesstimat of 15 degrees static and it ran GREAT each time but I wanted an accurate 18 degree measurement.....!

Okay...doubling the accurate measuring capability of the factory timeing tab without inaccuratly applied balancer tapes by a nearly invisible 30 second modification to the engine balancer.


Here we go....12 degrees of Advance is measured on the factory tab...and 2 degrees of retard. So I rotate the engine around to place the factory balancer notch directly opposite 12degrees on the factory timeing tab (each mark on the tab is 2 degrees of rotation).



The degreeing tool is a simple fine cut triangular file....no measurements, no tapes to put on wrong and then fly off, just a file come engine degreeing tool.



With the factory balancer notch at 12 degrees Advance, carve a smaller notch at 0 degrees (TDC). Outline em both in silver sharpie or white out or what ever ya got handy.



Now I had the motor rough timed at an estimated 15 degrees BTDC....the factory balancer notch above and off the scale of the tab. With my extra notch carved I started the engine, put on the timeing light and the new smaller balancer notch lined up at the first mark above 0 on the timeing tab....so, the 12 degrees on the tab, plus the first mark on the tab equals 14 degrees BTDC. Pretty close considering I eyeballed the setting initially, (The guesstimate of 15 degrees BTDC placed the factory balancer notch off the top of the factory tab as you recall.) This is much more accurate. I can even wiggle in odd numbers like 17 or 23 degrees BTDC by placeing the new smaller balancer notch between the marks on the timeing tab.

So, I set the timeing at + 3 Advance marks on the timeing tab against my new notch which equals 18 degrees Advance. Now I'm at what Mr. Langdon at Stovebolts initially recommended when running the HEI distributor conversion on this lil engine. I locked down the dizzy, tweeked the idle to 2 full turns in from first contact and shut John Lee Jr down. We'll get another test drive tomorrow morning to work. But I can say, mileage is up....I was useing about 1/4 tank to make the 78 mile round trip to Bragg at 55 mph. I used a lot less than that today (last nights settings, #4 on the chart below) at 65 mph. I'm gettin excited here.

[Sharps40]

So then we got the crazy idea of checking the advance on the dizzy....how to measure 30+ degrees at 3000 or so RPM on a 12 degree factory timeing tab?

Read on.....

[Sharps40]

My Tach/Dwell/RPM meter reads a 6 up to 2500 revs and I can guestimate 3000 RPMs before it pegs out.

So, wired a screwdriver to the bell crank so I could steadily lever the throttle, pulled and plugged the vacuum advance and marked another reference point on my balancer, just with sharpie and just below the one I filed in..... No additional notch this time, two is enough.

Just a lovely, (shows up perfect under the light) silver sharpie mark. It let me count all the way to 36 degrees on the factory timing tab!!

A hot recheck indicate John Lee Jr is sittin right close to 18 degrees BTDC static timing at 550 RPM.

I levered it up to a steady 1500 RPM and lit up the wheel counting out and recording 24 degrees advance.

Levering up to a steady 2000 RPM, it was right above 30 degrees so call it 31 degrees advanced.

Finding the steady spot at 2500 RPM it read a whisker over 33 degrees.

Moving further up in the exhaust note, at my estimated 3000 RPM mark on the meter, the crank showed me a strong 35 degrees.

I think the mechanical and static setting together is prolly pullin in just about the right amount of advance!!!!

[NixxiN]

is the more to that set up page? I'm working out a holley 5200 (weber clone) and want to get it running as good as your seems

[Sharps40]

Sent ya a PM wit the carb info since this is the Dizzy thread.