5abivt

I have a dual sync distributor in my car and when I popped the cap off the rotor moves say 5-8 mm or so. It feels like quite a bit.

I'm trying to chase a condition where I'm at steady throttle the a/f ration is bouncing around considerably. Since under steady acceleration the a/f stays pretty steady I'm starting to think that at steady throttle the distributor play is causing the timing to change because the motor is accel/deccelerating naturally with its firing.

How much should a rotor move under the cap?

Aardwolf

5-8 mm is an insane amount! If I remember correctly the end play should be .006-.010, I shimmed mine when I had it out. I used two of the thinner shims in the kit from Jegs. Mine had to much play and it is set correctly now. For the stocker you just tap out the roll pin and add the shim/gasket under the gear. Easy! I did this two years ago, everything has been fine.

5abivt

I'm not getting the shim thing. When i grab the rotor with my hand i can rotate it 5-8mm counter/clockwise.

Aardwolf

Ahh, I thought you ment up and down end play! Yes there is some side to side, I have not measured though. So, TTT.

Mr6spd

5-8mm is too much. What combination of cam gear / distributor gear materials are you running? It may be an issue of serious gear wear.

coupeguy2001

If you have that much, remove the distributor, and check for a serious wear pattern on the cam gear

5abivt

It just didn't feel right. Sorry about the shim thing I sort of figured you were talking about something different than what I was. The distributor is an accel dual sync. I believe the gear is a blackish metal. The cam I am running is a solid roller. I have no idea about what type of gear I should be using although I have read about the different materials.

I will be calling Accel tommorow to see what they have to say. I'm going to make them send me a new revised unit before I get stranded again 200 miles from home because of a faulty distributor.

Perhaps the gear wear is the reason like mr 6spd said. I do spin the motor pretty high but lately I have not save a few times doing some wot datalogs. I have about 1200 km of daily driving on this distributor. Can a wrong combo of materials wear it that fast?

Mr6spd

Yep, that's your problem right there. The gear on the billet solid roller cam (unless it has a pressed-on iron gear) is not compatible with the standard distributor gear.

Bullshark

I purchased an Accel Dual Sync distributor for my RamJet 502 awhile back. I am in the process of dumping the MEFI 3. After taking a close look at the design, I have a few reservations. The rotor is held in place by two 5/64 allen screws use to lock it down after competing the Rotor phasing part of the alignment process. Looks like a pretty flimsy way to secure something so important.

Bullshark