[wakesupremo]

I have read that a dial back timing light cannot be used with an MSD digital6 ignition, but , I have also read that if the light is powered from another source other than the engines battery it 'might' be ok. I have a Gunson workshop dial back light that, at times, I have experienced erratic results even when powered from a battery pack . How do I know that What im reading is actually right? or how do i ensure 37deg btdc without a dial back>
Thanks in advance.

[242177P]

Make an extra mark on the balancer, a little
stripe of Liquid Paper will make it easy to see.
When that lines up with the 0 on the timing
tab... No dial back needed

[Dragncar]

I have used a digital dial back timing light powered by the battery with a MSD-7AL2 for many years. Works just fine.
You can double check it with your timing marks if you like.

[Formulajones]

I use a sears dial back timing light, an analog unit and it's worked fine for years with my digital 6 MSD as well as the other cars with MSD boxes.

When checking total timing I'm revving the engine above 3000 rpm anyway to make sure all advance is done. At that rpm the multispark is done and the light is rock steady.

[Radman]

The MSD will fire the spark plug 6 times at low RPM. As you raise the RPM the spark count per cycle decreases. At 3000 RPM or higher there is only 1 spark per cycle. The statement about not using a timing light is for the lower RPM where there is more than one spark per cycle. It works fine at 3000 or higher. Play with your total advance and get the best overall performance for your engine. With my iron head 389 I ended up with a 34 degree full advance to stop pinging.

[Jay S]

On one on my Mopars I have a factory electronic ignition and an MSD6AL that I can switch back and forth in a few minutes. Changing them back and forth I have never noticed any difference anyplace.

I bought a cheap summit adjustable timing light to keep in the race trailer. Works but is more than 10* off of the engines actually timing with a different timing light.. Those adjustable timing lights can vary the timing more than any of the ignition boxes. Set the timing were it runs the best.

[Schurkey]

MSD has a bulletin--originally from decades ago--about not using dial-back timing lights. They used to recommend a certain Craftsman light, and of course their own.

My experience has been that some dial-backs are more affected than others. My ancient Mac light seems to deal with MSD just fine.

[wakesupremo]

Thanks for all the replies

[RA66GTO]

Just putting this out there for general info.

Having used a dial back timing light with MSD for many years with no issues.

Recently went to timing controlled EFI, felt that it just never quite ran like it should. Re-degreed everything, verified mechanical timing, etc, etc.

Eventually bit the bullet for the MSD Timing light and found that there was was a difference of 8* on Static Timing between the dial back and MSD timing lights.

Needless to say, car runs beyond expectations now.

[Schurkey]

Originally Posted by RA66GTO

there was was a difference of 8* on Static Timing between the dial back and MSD timing lights.

Needless to say, car runs beyond expectations now.

So the Diat-back light made the engine run 8 degrees retarded? Meaning the dial-back timing light showed 8 degrees of false advance, leading the distributor to be turned 8 degrees retarded from where you actually wanted it?

[RA66GTO]

Originally Posted by Schurkey

So the Diat-back light made the engine run 8 degrees retarded? Meaning the dial-back timing light showed 8 degrees of false advance, leading the distributor to be turned 8 degrees retarded from where you actually wanted it?

Correct.
Dial-back showed static timing with the EFI/MSD 8* retarded in comparison to the MSD timing light.