View Full Version : r-2 spark modifier

big jim
07-22-2006, 10:53 AM
morning gentlemen: I am in need of a nos 1558290 vacuum advance pot, mine is history...no luck with the vendors I've called if you have oneplease advise. Or is there a replacement?Thanks..JG

07-24-2006, 10:29 AM
Try Dave T. on the east coast. I ran into a similar problem, but then my Prestolite has been modified with the Chrysler electronic conversion and so my solution may not work in an unmodified Prestolite. One of the gripes I have with the Stude vendors is that they seem to have the attitude that since they are dealing with an orphan auto that they are then free to foist on us any old part suitable or not. In my case a PROMINENT Stude vender was selling (about a year or two ago) a vacuum advance unit for the Chrysler altered Stude Prestolite distributor which must have been originally intended for a HEAVY Chrysler vehicle (truck?) because the vacuum needed to be 16-17 inches of Hg before the advance would even start to come into play and on an R2 you could well never see that much vacuum (and the factory manual states that vacuum advance is set to be all advanced at 13 inches of Hg --so what good is a can which doesn't begin to advance until 16 inches Hg?). At that time (two years ago) I searched all local sources (including Chrysler) with no luck on any "old" vacuum advance units at all. The ONLY source I could find was Dave T. and I almost didn't check with him because of an earlier issue (see above)....... Good luck, and you may need to go away from the points and go to the Chrysler conversion and then use the unit Dave T. sells (it is adjustable). At that time I even called Jegs and Summitt about an advance unit for Chrysler and they laughed at me (what do people running Chryslers do, I wondered?) as NONE are available. Again good luck, and be careful about what you buy and from whom.

wagone and the R2 Avanti

big jim
07-24-2006, 11:02 AM
thanks wagone, i have a pertronics unit installed, and did discuss conversion to chrysler, however why convert ($250.00)if I don't have to. We'll see, I may have no choice!!!! thanks again

07-24-2006, 04:36 PM
Just found this on eBay - will it work?



Clark in San Diego
'63 Lark Standard

07-24-2006, 04:57 PM
No, that one is for the "window" type Delco distributor.

Road Racers turn left AND right.

07-24-2006, 05:10 PM
Is it for the Prestolite single or double point original set-up?I know the single point ones are all but impossible to get.You may have to go with a used one for which I'm sure someone has.

07-24-2006, 06:14 PM
It won't fit any Prestolite type distributor. As noted above it is for Delco distributors and would be of no use in a Prestolite.

wagone and the R2 Avanti

big jim
07-24-2006, 09:51 PM
thanks guys, no that is thewrong item, but i appreciate the thought.. mine is r-2 dual point converted to pertronix. I'll have to keep looking cause mine has a hole in the diaphragm and will not hold a vacuum.thanks again!!

07-24-2006, 10:49 PM
There is a shop in Tulsa that changes the distributor from vacum to centrifical advance and sets the curve. I have one that they done and seams to work just fine. You might look for a shop in your area that does this.

Dwain G.
07-24-2006, 10:50 PM
In my notes I have this, don't know who originally found it:
Vacuum advance rebuiler
Jim at Odd Parts
18853 Orange Ave.
Sonoma, CA 95476
1-707-738-9661 or cell 1-707-939-1457
Here is a couple numbers for the vacuum advance used in the dual point dist. They may/may not be available anywhere:
Essex- 9-217
Prestolite- stock # 6-66, part # IAZ-2023LF
(credit Randee for these)

Dwain G.

07-25-2006, 07:33 AM
I bought a "Modifier, 1558290" from Myer's Studebaker, (740 674-4897), about two years ago. It was in a Prestolite box, and matched the old one on my R2 distributor. R1 is the same part; just shimmed differently.
Never push the breaker plate against the advance. It's just too easy to break the advance can loose from its bracket; or snap the pin off the breaker plate. Check the action with a vacuum pistol.
It's a good idea to take the breaker plate apart, to clean and lube the bearing.
I found very flexible 16# wire, for the ground and the primary lead to coil, which must flex when the vacuum advance works, @: http://www.robotmarketplace.com/marketplace_wire.html . Insulation is silicone. I haven't made sure it's safe with petroleum, yet; but I don't expect problems. It should be ok with the heat. It turns out that's partly a matter of the copper strands being tinned. Corrosion on copper reacts with silicone insulation and lowers the safe operating temp. The 16# has tinned, fine strands - 660 of them! I'm using a flag style ring terminal at the points. I run the ground wire for the moveable breaker plate, from the condenser screw, through the grommet with the wire for the points. It's longer and more flexible than stock, even with standard primary wire.
Mike M.

big jim
07-25-2006, 08:16 AM
thanks Mike I need to call John again.. at the time I talked to him I had not determined the exact nature of the problem...I do have the distributor completely apart with plans to rebush and reset end play.thanks again JG

big jim
07-25-2006, 04:58 PM
gentlemen....FYI john myers DOES HAVE the vacuum pot in stock,reman i suppose, he needs core..thanks for all the help JG