Mopar Performance Distributor adjustable advance?

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65barracudaLA

65barracudaLA

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I got one of those FBO limiter plates and was about to set it in the distributor, when I noticed two things. At first I noticed that the reluctor was a bit unevenly worn and the pick-up wasn't parallel to it. I'm sure that can't be good.

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Upon closer inspection it looks like the plate is bent. I think I can bend that back.

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I noticed that the FBO limiter plate is not going to work, but that the adjustment can be done with an allen wrench?! I don't know for sure that this is a Mopar Performance distributor and there is no part number on it, but when I looked at photos of MP distributors, they look just like it. Anyways, what I like about the FBO plate was that you could set your initial and then set total based on that number plus whatever added up to 34. My initial was 22, so I was going to use the #12 slot. I wish I had opened that distributor before I ordered the plate and the springs, which I don't think will work either. Anyways, any idea how I can set this up without having to take it out again 15 times?

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FYI, it's for a '69 318 in my '65 Barracuda, 675 heads, so compression ratio should around 9.1:1. Edelbrock Performer intake and 1406 carburetor. Mopar electronic ignition.
 
I've got the same distributor and I set mine for about 14* on a dist. machine. I can take the measurement between the plate and the stop and give you that number. @halifaxhops told me that these distributors were sold with a set of "keys". Basically different thicknesses to correspond to degrees of advance.
 
First, throw the FBO plate in the nearest garbage can. They're worthless, because they are inaccurate pieces of CRAP. Say you install it on the "16" slot. You'll probably get 20. And so on. They just give way too much than what they're marked for. Everyone on here who has tried one has had the same result. Several of us have told what's his face about it but been ignored and he was even rude to me about it, so screw that guy. I just weld the governor slots now. Yours is a later MP distributor made by Mallory and those are NICE. See that little black screw at about 11 o'clock on your last picture? That's how you adjust your mechanical advance. Easy peasy. Screw that FBO guy.
 
Trial and error it is. I just set it in the middle. From what I (just) read it's adjustable from 0-28 degrees?! So half that should be 14, so I'll see what it does with timing at 20 degrees. I'll see if I can find these tuning keys. Anyways, the distributor came with the engine and I had never really looked at it. I'm glad I did.
 
65barracudaLA said:
Trial and error it is. I just set it in the middle. From what I (just) read it's adjustable from 0-28 degrees?! So half that should be 14, so I'll see what it does with timing at 20 degrees. I'll see if I can find these tuning keys. Anyways, the distributor came with the engine and I had never really looked at it. I'm glad I did.
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No, it's not trial and error. Get a grammar school protractor. Stick the rotor on. Put the protractor above the rotor so the tip or the rotor is pointing to zero. Now, twist the rotor advanced and see how many degrees you have. Multiply that times 2 and you have crankshaft degrees. So if you have 5 degrees at the distributor, that's 10 crank degrees. Get it? Screw that trial and error chit. And screw that FBO guy. lol
 
That is a older Mallory style adjustable mechanical advance Distributor. There are keys out there if you can find them that fit in the slots and you back the plate up to. Very good distributor. You can also change the springs for different rated of advance.
 
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I used a solid plate from a lean burn and did away with the vacuum advance. You can get to those button allen heads with the distributor in the car. Just have to turn the engine. I set mine for a 20 degree retard for start up. One light spring . Once it fires it goes to 35 total. It starts at 15 btdc and idles at 35.

With a digital MSD the retard is built into the box so you can just lock the advance on the distributor and let the box do the start up retard. Worked for me. Mine idled at 1600 Rpm's and would spin at times to 8500 on shift depending on hook. rev limiter set at 9300.

Now a run a billet MSD distributor due to bearings instead of bushings. Did not make one difference in performance.
 
Yeah. I forgot about the keys. .....and I actually have a set somewhere. Yeah get a set of those. Then it sho nuff ain't trial and error. lol

....and screw that FBO guy. lol
 
Just use the butt end of a drill bit to set the width of the slot where you want it. There's a chart posted on here somewhere that shows width and associated advance it provides.
 
mopowers said:
Just use the butt end of a drill bit to set the width of the slot where you want it. There's a chart posted on here somewhere that shows width and associated advance it provides.
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You said butt.
 
Do you guys know if that chart above works for both the adjustable MP distributors AND the old factory units? I've always wondered that.
 
Here are some measurements of the keys. There are two styles of Mallory advance and I can't recall which these specs are for.
28 degrees, .496
26 degrees, .476
24 degrees, .458
22 degrees, .442
20 degrees, .424
18 degrees, .406
16 degrees, .390

Basically, every 2* is about .016-.018 change in width. 14* is going to be in the .372-.374 range

Here are some measurements from the other Mallory set. I believe these are the numbers for the OP's distributor.
Thickness of some keys from the mallory kit.
12* .125"
14*: .140"
16*: .155"
18*: .170"
20 0.185
22 0.205

Bust out those drill bit shanks!
 
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mopowers said:
Do you guys know if that chart above works for both the adjustable MP distributors AND the old factory units? I've always wondered that.
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No. The factory Mopar style has an entirely different mechanical advance. It's non adjustable.
 
You guys make me want to cry. Why? Because people assume that everyone understands what they are talking about. I am not an electrical engineer, or distributor guru, or carburetor airbleed tip in guru either. I have FBO parts in 2 cars, one is running fine with them. The other one isn't together yet, but has the FBO distributor and module. All came recommended from a respected engine builder that occasionally makes comments on this site. Sometimes I feel like I am back in the Army, and my poncho fell apart on a forced march and now I am on the side doing push-ups for embarrassment, so that it doesn't happen again! I have no idea what those red gauges do yet, I have a set, they came with the new distributor. Just haven't gotten that far. Maybe Red Green can help me with some duct tape! I will keep watching, we're all in this together.
 
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