Precision distributor Install before Dyno

[jgkurz]

I am preparing my engine for the dyno and would like my timing set as close as possible beforehand. I am using an MSD 6AL2-Programmable so my MSD distributor must be locked and set to the max advance the engine will ever see. In my case I want to lock the distrbutor at 40deg BTDC.

I set my damper at exactly at 40deg BTDC on #1 cylinder. I then installed the distributor so the rotor was pointed at #1 cylinder, or as close as possible. My MSD MAP will pull out 25deg of timing at start so initial is 15deg.

To be even more precise, should the rotor be lined up with the leading edge of the #1 post instead of directly in front of it?

I will certainly check everything with a timing light, but I'd like to avoid any major adjustments.

Thank you!

[Royce]

It is really not that easy to set timing by lining up the rotor. Distributor phasing comes into play  Really the only way you can get within 10 degrees is to set it with the engine running.. I would not start at 40 degrees  work up to that. If you set it with the pointer on the damper at degree you want  aim the rotor at the leading edge of the terminal.. At least that should get you running..

[jgkurz]

Thanks Royce. I had not thought about rotor phasing. That will throw a wrench into my plans.. : )

[Joey120373]

You can get pretty close if you look at the actual pick up inside the distributor, under the rotor.
If you line up the "tooth" on the distributor shaft exactly with the metal tab that is in the center of the pick up coil, you will be within a few degrees generally.

I used to do this all the time when I was wrenching for a living, works great.

[jayb]

The easiest way is to set it on the dyno, before you want to start the engine.  Use a timing light and crank the engine over before you put fuel in the carb.  I would agree to start lower on the timing, maybe 35 degrees.  Then with the 25 degree retard in the MSD, when you turn the engine over with the ignition on, you can adjust the distributor so that you have 10 degrees BTDC.  At that point, you will be very close to 35 degrees total when the engine is running.  I do this all the time on the dyno; it is the most reliable way to get the engine timed correctly right from the start.

[jgkurz]

Great info. Thank you.

[CaptCobrajet]

Mr. John, you will only want 32-33° total with those heads......

[jgkurz]

I plan on 32deg max advance under power. The 40deg is for lean cruise. I have an extra cap with a hole near #1 cyl so I view rotor phasing and adjust. I may go higher than 40deg if I can keep phasing from getting out of hand.