Was wondering if its possible to check the alignment of the rotor to cap on an MSD distributor for a big block? How is it done?

MSDs don't allow for adjustable rotor phasing. Rotor to reluctor alignment is fixed.

But to check rotor phasing, manually set the balancer to between 25-30 degrees BTDC on cylinder #1. Then remove the cap. When you move the rotor to the end of what the mechanical advance would do, the rotor should be pointing directly at the #1 terminal. It always is.

To change rotor phasing:
For EFI I have to change the rotor phasing because EFI needs a reference pulse from the distributor at about 50 degrees BTDC. In cases like this I disassemble the distributor, remove the reluctor, machine a new locating groove for the roll-pin, and reassemble with all advanced locked out. That's the only way of changing the reluctor to rotor phasing on an MSD.

Hears how it is done
http://www.msdignition.com/instructions/...s=rotor+phasing

and hear is what you need be cautioned when you get it where you want lock tight the screw
http://www.summitracing.com/parts/MSD-84211/

I appreciate that, thanx.

The MSD tech app is nice, but it doesn't apply to Mopar distributors because you still can't change the phasing without fabrication work.

Is the Cap-Adapt and adjustable rotor no longer available from MSD? That's how I did it on my RB MSD dist. Runs my Commander Pro injection and ignition.

Kevin

Found it on Jeg's. http://www.jegs.com/i/MSD-Ignition/121/8420/10002/-1?parentProductId=747900

Kevin

That cap a dapt looks pretty good. I take it the collar screws down like a MSD cap and then the ford type clips on top. Does clearance with the valve covers become an issue because the cap has a larger diameter?

My MSD dist is the early one that uses the "window" style GM cap. The adapter goes on like the old cap and then the Ford one goes on the adapter. We used a hole saw to cut an old Ford cap so we could see where the rotor was with a timing light.

I have chrome Edelbrock covers on my 493 with RPM heads and I had to "clearance" it slightly on the upper right corner. Basically used a small ball pien hammer (4oz?) to concave the corner.
The cap hides it nicely .

Kevin

Sure would like to see a picture.

I don't know if this one shows what you need to see or not.

Kevin

Thank you. Gives me an idea.

Anyway you look at it I need to buy an extra cap and cut a hole in it to chedk the phasing. should be interesting.

get an old one from a friend.