Vacuum Advance Parts Source

[grey beard]

In a post on the car side, Don Coatney said he took his distributor off and was surprised to find his vacuum advance was shot. Had the same problem myself. In fact, I've tried for the past few days to find a source for these elusive devils locally and have stricken plumb out. Now, I want to tell you all that I've got a NAPA parts counter man who will go through proverbial hell with a bucket of ice water, just to find anything I tell him I can't get. He's downright good. But he struck out on vacuum advance units.

This leaves Roberts - $69.95 and Terrell - $65.00. Man, that's gotta' be some kind of highway robbery! Anybody have a local source that might be a little more user-friendly? Sure would like to find one.

Methinks what is happening here, folks, is that the newer oxygenated, ethanolated, methylated-whatever gasolines are getting the fumes into the vacuum pots and killing the diaphrams. If this is fact, we may ALL be looking for vacuum advance units pretty soon.

You can easily check yours out to see if it is leaking, just by pulling that little 1/4-inch line that goes to your distributor off at the carburetor, there on the passanger's side of the engine, put a short piece of vacuum hose on the end of the line, and pump on it with a vacuum hand pump a few strokes. If it holds vacuum, you're okay. What, no vacuum pump? Well, then pilgrim, just suck on it with your mouth. That''s what this old man does. If you can pull a vacuum and hold it for a few seconds with your tongue on the opening, your advance unit is still okay.

I'm willing to bet that many of our engines are running around without the benefit of this part of the distributor advance curve. Man, but that does hurt the overall economy and fuel mileage. Ouch!

Somebody please find me a vacuum advance - please . . . . . .

[billwillard]

I would try NAPA. See them on ebay all the time.

[Aaron]

I'm going to show my ignorance tonight as I am still a rookie... In the picture I have attached, is the red arrow pointing to the the vacuum advance?

[YourPowderCoating.com]

I'm going to show my ignorance tonight as I am still a rookie... In the picture I have attached, is the red arrow pointing to the the vacuum advance?

yes, thats a vacuum pot w/ diaphragm inside. the engine pulls vacuum on it which in turn pulls on an arm that is connected to the plate that the points are mounted on, when the engine pulls vacuum under acceleration, it advances the timing via pulling / turning the round plate.

w/o vacuum advance or mechanical advance, the motor will run, just not very efficiently.

[grey beard]

To further complicate a nasty issue of availability, I currently have three different type of vacuum advances lying on my bench. The arms that reach inside the distributor body are of different shapes and lengths. Here, just when you thought it was all figured out, someone throws in a curve like that . . . . . . Go figger.

[Reg Evans]

Dave, I have a few in boxes here too. Post a photo of yours and I'll see if I have one like it.

[grey beard]

Reg,

You won't need a picture to identify this one. The difference in vacuum advance types is all in the length and curve of the arm that extends through the distributor body into the breaker plate, itself. They all look alike from the outside of the distrbutor. The one I need has a straight-through arm with a vertical step upward in it, as it sits on the body. Most other arms curve toward the outside a little, but are straight as viewed from a vertical plane.

I've learned a lot about Chrysler distributors in the past few days. There are at least three distinctive styles. The latest, and best one from my viewpoint, has a 3/4-inch round hole in the body for the vacuum advance arm to go through and has a ball bearing breaker plate for the vacuum advance to operate. Earlier models have a pivot point that the vacuum advance moves against, but with this type the dwell also changes when the vacuum advance moves the points - not the best design.

I have several incomplete distributors here in parts. Some use the smal cap and rotor and others use the larger, newer cap and rotor. These two styles each take a different points and condenser style, as well. If anyone needs any pieces, let me know. None of them have good vacuum advance units though.

Bought new points and condenser, cap and rotor at NAPA this week. Would you believe they cost me over $65 bucks? That's enough to make a man switch parts houses.

Yes, Reg, if you have a good one of the type I need, I'd be glad to buy it from you. Just let me know.

[grey beard]

Reg - or anybody else,

What I really need most of all just now is the pot metal piece that attaches the vacuum advance cannister to the distributor body. It's held to the can by two screws and to the distributor body by two more. Some vacuum advances have this part spot welded to the can and are not removable, but others ae pot meal. This is the type I need just now.

Sure would like to buy one of these if anyone has a spare they will part with.

Thanks,

[Reg Evans]

Dave, I just looked at 8 of them on my shelf and all the bases are stamped steel.

[YourPowderCoating.com]

Reg - or anybody else,

What I really need most of all just now is the pot metal piece that attaches the vacuum advance cannister to the distributor body. It's held to the can by two screws and to the distributor body by two more. Some vacuum advances have this part spot welded to the can and are not removable, but others ae pot meal. This is the type I need just now.

Sure would like to buy one of these if anyone has a spare they will part with.

Thanks,

can ya drill one of the "spot welded" ones and either tack on the new piece or jb weld that bad boy on to the vacuum pot.

if the ones that are spot welded are common, get the dremel out and drill the spot welds with a small bit.

to "re-tack" may be a bitch due to the heat and rubber diaphragm, jb is some tuff stuff and would indeed hold if the surface is prepped properly.

[grey beard]

Wow! Eight vacuum advances! I'm impressed. That's what I call being prepared. I realize you have more than one MoPar. That is really a great inventory. I'm sure you've been at this a while.

Reg, do any of those eight pots have a dogleg that goes up mebby 1/8th to 1/4-inch as it goes into the distributor body? That is the one I need. Just let me know and I'll send green stuff, 'er whatever it is you need.

Thanks,

[OLD DODGE]

Grey Beard,

Is your distributor an Autolite? If so, post the model number and I should have an Autolite parts drawing and bill of materials for it if you are interested.

I could see if that vacuum advance was used in other applications.

Here is a drawing for an IGS-4108

[grey beard]

It looks just like your drawing, but the tag says Chrysler Corp. Of course we all remember when Autolie was a division of Chrysler. Will the distributor number help? Looks just like your drawing from a parts book.

Thanks

[OLD DODGE]

I posted that one and another on the 39-47 Dodge Truck Forum for somebody. I would think yours might be a different number.

[OLD DODGE]

If you want to post a pic of your distributor's tag I'll see what I can come up with.

Kevin

[grey beard]

Hi Kevin,

Distributor's back in the engine, so I can drive, but here are the tag numbers, laid out in approximate fashion:

1233564

IAP - 4101-1 2DCC9885

I have looked at several other distributors. It appears there are several units that fit our engines, however they vary a great deal in the breaker plate and vacuum advance areas. Especially the vacuum advance attaching arms ares are quite different from each other.

So far, I have found two different size caps - small and large - and several different configurations of tab/slot orientation for each cap, within these two general sizes.

MoPar surely must have used a bewildering variety of distributors. Must'a been fun being a parts man, back in the day, what?

Any help you can offer will be much appreciated. Wish these advance units had numbers stamped on 'em, but no such luck.

Thanks

[OLD DODGE]

I believe the IAP-4101 is the Autolite number. The parts book I have is about 6 inches thick so it should be in there. I'll see if I can get it scanned this weekend and post it next week.

Kevin

[Big50Dodge]

I believe the IAP-4101 is the Autolite number. The parts book I have is about 6 inches thick so it should be in there. I'll see if I can get it scanned this weekend and post it next week.

Kevin

This was my thinking - instead of checking NAPA, maybe go with an industrial supply house in your area that has large fork trucks. These engines were used in serveral applications, and getting more to the nitty gritty, the ditributors were used in various engines.

Not sure about IAP, but I can confirm IAT-4012 is a Autolite number.

[Don Coatney]

This was my thinking - instead of checking NAPA, maybe go with an industrial supply house in your area that has large fork trucks. These engines were used in serveral applications, and getting more to the nitty gritty, the ditributors were used in various engines.

Not sure about IAP, but I can confirm IAT-4012 is a Autolite number.

Most, if not all, industriual applications do not use a vacuum advance. Reason being, most are governed engines running at a set speed to run a welder, air compressor, etc. or governed to not exceed a pre set RPM. A vacuum advance is designed to increase economy when an engine must frequently change speed due to road and traffic conditions. Doubtful that an industrial supply house would be any help in finding a vacuum advance pot.

[OLD DODGE]

Grey Beard,

All I came up with for your distributor was a one page parts list that does include the vacuum unit. I posted four pages for Big50Dodge's distributor there also. I couldn't reduce the file size small enough to post it here without it looking like garbage so here's a link to them. I hope it helps out. It's my first try with photobucket so I hope the link works.

http://s682.photobucket.com/albums/vv183/DODGETRUCK/AUTOLITE%20DISTRIBUTORS/

[Jim Gaspard]

I happened upon this source for a Dodge Pilothouse flathead vacuum advance while searching for another part.

http://cgi.ebay.com/ebaymotors/VACUUM-ADVANCE-CHRYSLER-DODGE-PLYMOUTH-DESOTO_W0QQcmdZViewItemQQ_trksidZp1742Q2em153Q2el1262QQcategoryZ34205QQihZ021QQitemZ310105843504QQtcZphoto

Good luck.

Jim in Dallas

[Young Ed]

Just heard about these guys on the 39-47 dodge truck group. They supposedly rebuild them.

http://www.daytonaparts.com/

[Merle Coggins]

The guys at Antique Auto Parts Cellar also rebuild vac advance units. They also say that they have a stash of NOS units as well. I found this out when I though mine was bad recently, but then I found it was just a loose connection so I didn't have to pursue it.

http://www.maritimedragracing.com/then_and_now_automotive.htm

Merle