HEP follow on discussion - Car specific timing issues

Didn't want to clutter up the other HEP issues discussion thread, so starting another specific to some issues i have with Mini.

I posted somewhere about my logs showing what appears to be very small timing advance numbers in boost. It seems like the number is off by about 10-12 degrees.
Today i hooked up the drbII because i wanted to check some things.
I had previously assumed mpscilink was maybe altering the actual displayed/logged timing advance. But the DRBII concurred with the previous observations. At idle in park the timing showed 1deg. Checking with a timing light showed the flywheel mark at about 12deg, and bouncing around.

I removed the cap/rotor/HEP and found i have the "good reman" distr. with the metal rivets. But there is some gear lash, and maybe a tiny bit of extra clearance with how the rotor engages the shaft.
So question 1, how do you adjust to take up the lash??

2. Why is the timing light showing timing events at about 12 BTDC, and the DRBII says advance is 1 deg? (This was checked with CTS plugged in, not like a normal timing reference setting process), which should have the advance showing up before the window, so like 20-18° BTDC.

I don't understand it.

I could be wrong, but doesn't the timing light set your base timing, then the 1* advance would be just the computer's advance from the base timing? IE: 12* base, plus 1* advance, would be 13* BTDC

I would think that the gear lash isn't that big of an issue when the engine is actually running as there's only load applied in 1 direction and the distributor is only along for the ride, anyway.

I remember Ed Peters talking about how Team Shelby would "mushroom" the ends of the distributor drives, then file them to fit to the top of the oil pumps to help with some of the slop.

As for the timing, I tend to agree with what EaZyE426 said, the timing light is showing you that you have your reference to the computer correct and the the DRB is showing that the computer is adding a degree based on the feedback the computer is getting based on its expected reference timing and sensors.

I guess my problem with that explanation is that is contrary to what Rob Lloyd has ssid when trying to explain the misconception of "setting base timing".
From how he put it, the total timing should be what gets logged or displayed inder "Adv" in MPScan, MPScandroid, or MPSciLink.
And the "base timing" is just to set a reference for the ecu.

Wayne, I would have to look at a DRBII again to confirm, but if it's the timing parameter I'm thinking of, it has always shown 12 or more on my DRB.

Quote:

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Originally Posted by Shadow

Wayne, I would have to look at a DRBII again to confirm, but if it's the timing parameter I'm thinking of, it has always shown 12 or more on my DRB.

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Thanks for the input Rob. I'm looking under the monitor screens, it shows up on a few, and on the sensors list.
Its raining here today, but i wanted to check what it says on Slug too, although I am using a Turbonator based cal on that too. My Spirit still has a stock sbec, but with a bad fuel pump I can't run it to test.

I remember checking with a timing light before, on my spirit where you could barely even see the timing mark until you unplugged the CTS. So that was even more advance in order for the flywheel mark to be before the timing window.

I did also notice the DRBII says my smec is a 139, and manual. I know it was a 139 based cal, but didn't know that was a manual smec. The auto trans bit is toggled in the configuration.

Timing is an essential part of the hp recipe, and I've never been confident that mine has been properly optimized, at least for the stock system I'm using.