Mopar Perf SB distributor - 30* mechanical advance?

[smolski]

Does this sound right to you guys? I believe a stock distributor would add about 18* mechanical. Can anybody confirm that these Mopar Performance ones (or, some of them) add 30*? Also, are the advance plates stamped on just the original ones, or are these stamped too? Thanks.

This is a Mopar Performance "performance advance curve" distributor that came with a 273-318-340-360 Mopar Performance orange box kit, bought new about 3 or 4 years ago.

[RobbMc]

If it has the gold colored mechanical advance with the thin advance weights and the adjustable limit, you have one of the MP distributors made by Mallory for MP. The mechanical advance is a Mallory YH (same as used in 90% of Mallory distributors). It is adjustable from zero (locked out) to 28 degrees. They are set at 28 degrees at the factory per Larry Shepard. I tried to convince him that 20 degrees would be better for most cars but he wanted the end user to be able to get 38 degrees total without having to have more than 10 degrees initial.
Personally, I find most cars with anything more than a stock cam prefer more initial (say 16 or 18 degrees) and less in the distributor (say 20 degrees).
You can reduce the advance in the distributor by loosening the two Torx head screws and rotating the stop plate.

[Mr.Sixpack]

I bought a new mopar performance electronic kit for a 440 and the mecanical advance was 33 deg.
Thats bad, so I had to change that.

[eric414]

i have a 10 sec race car with a unilite should i lock it out and if so how do i perform this action?i was told that this would be me a better 60 foot and the engine would rev quicker.

[RobbMc]

Originally posted by eric414
i have a 10 sec race car with a unilite should i lock it out and if so how do i perform this action?i was told that this would be me a better 60 foot and the engine would rev quicker.

The more cam a car has the less advance you want in the distributor and the more initial you want to run.

A ten second car will generally have a cam with at least 260 degrees at .050". With this much cam the car may indeed run better with no advance in the distributor and all the advance initial(ie locked out).

If the distributor has the YH advance (there will be an "H" on the end of the part number on the tag on the distributor) the advance will have two button head Torx screws. Loosen these two screws and rotate the stop plate so that the advance cannot rotate at all. This will "lock out" the advance.

To get to the advance, remove the cap, rotor and cap clips and pull the Unilite plate out.

If the distributor is more than about 8 years old it may not have a YH advance. If this is the case you will need to drill and pin the sleeve to the shaft to lock the advance.

[eric414]

Robbmac,my cam is 276-280@50 so it should be locked out?

[RobbMc]

Originally posted by eric414
Robbmac,my cam is 276-280@50 so it should be locked out?

Every car is different so there is no way to know for sure but to try it. However, with that much cam my guess is that the car will run faster 60 ft times with the advance locked out and the timing set at about 36 degrees initial.

[eric414]

Should i also run a MSD retard box retard the timing in high gear.

[RobbMc]

Originally posted by eric414
Should i also run a MSD retard box retard the timing in high gear.

No, you should run a Mallory 618-1 or 618-3 high speed retard.



Or if you need a CD box you could run a Hyfire 7 with built-in rev limiters and retards; no chips required.

High speed retard tends to change mph more than et but yes, pulling about 4 degrees out in high gear can lower et.