distributor vacuum advance

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MoparChic71

MoparChic71

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I think I need a new vacuum advance unit and was looking for some input on which one to use. My car is converted to the Super six setup and I wanted to know if I should change the vac advance over to the Super six one. Right now my distributor is the stock 198 with petronix and a 225 vac advance from a 69 slant (is there a difference in year/motor?) Also the parts store lists 2 different options for vac adv for a (1978) super six anyone with a part number would help. Would the Super six cars having electronic ignition be a different advance? Thanks. :)
 
WARNING: One huge problem you are likely to encounter is that modern Chineseo parts stores may very well have one or two sizes fits all. This is also true when you buy a typical "rebuilt" exchange distributor...............you don't know what you are getting.

Look in the back of section 8 (electrical) of your shop manual, the specs for the advance on the distributor is in there. Generally speaking, the difference is performance, and smog, not whether it's electronic or points so far as "amount" of advance.

Generally speaking you want to pick a performance option for a distributor rather than not. There are exceptions, IE some of the V8s were dual point, so parts don't interchange.

Free manuals:

http://www.forabodiesonly.com/mopar/showthread.php?p=1970088617

http://www.mymopar.com/index.php?pid=31

Below is an example page out of the '69 service manual. Go down where it says Advance--Vacuum (Distributor Degrees at Inches of Mercury)

What this means is as you take a pump, and start to apply the indicated amount of vacuum on the advance unit, it should advance about the amount shown TIMES TWO at the crank. NOTICE these are what is called "distributor degrees". The distributor rotates at 1/2 crank speed, so the advance measured "at the distributor" has to multiplied X2 when measured as you would use a timing light at the crank
 

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I see a good tech jump in and verify this for us :thumleft:
 
I always hear about vacuum pumps. Where do I get one? Sounds like it would be very useful with these old engines. (My car is 15 yrs older than I am lol but I love my lemon) very useful info 67 dart 273 thanks that does help. So the vac advances will say the specs when I'm looking at them?
 
^ Your engine is a great vacuum pump. I'd take the advance off and observe it's operation from idle to say, 2500.

If you just gotta have one, autozone used to rent them, harbor freight might have them.
 
get the VC-208 can from summit racing. set the adjuster about 5-6 turns out to start. You'll need to recurve the distributor as it has alot more advance than stock.

16 initial
30 total mechanical by 2200rpm
(with VC208 can) 52 total w/ vacuum adv
 
I hear you about harbor frieght....almost always cheap china crap. Vc208 do you know the degree of advance on it? How do I recurve my distributor? I don't know very much about distributors just what they do. I was looking on rockauto.com but there's so many options i have no clue. I searched under a 78 dodge aspen since they had the factory Super six option but there's 4 options and non if them say the degree. :(
 
Really simple. As long as the vacuum advance can you get has a hex just behind the hose nipple (I said nipple, heh heh heh huh huh huh), it is an adjustable unit and will not matter what brand it is. you can adjust it as needed.
 
MoparChic71 said:
I hear you about harbor frieght....almost always cheap china crap. Vc208 do you know the degree of advance on it? How do I recurve my distributor? I don't know very much about distributors just what they do. I was looking on rockauto.com but there's so many options i have no clue. I searched under a 78 dodge aspen since they had the factory Super six option but there's 4 options and non if them say the degree. :(
Click to expand...

22 crank. you'll have to find someone with a distributor machine. if you want pm me and we can talk about getting you one
 
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