| Author |
Message |
rich (Dino2400)
Junior Member
Username: Dino2400
Post Number: 229
Registered: 10-2001
| | Posted on Monday, May 26, 2003 - 12:09 pm: | |
Yes, you can trigger a capacitive discharge type electronic ignition with points. This is how the Dinoplex cars are (206, 246, various alfa and Ferrari race cars of late 60s and early 70s). The difference is that the voltage is no longer running through the points and therefore they don't burn up. (Unless you have to switch to "emergencia" because the dinoplex has failed, ha!). I replaced my dinoplex with a modern MSD box but still kept the points - I liked the idea that if the MSD went out, I could still drive the car. Can't do this if you swap to optical sensor. Of course the optical sensor is supposed to last a long time and you could carry a spare I guess, but when they go, they go quickly. |
Russ Gould (Russ)
New member
Username: Russ
Post Number: 19
Registered: 2-2003
| | Posted on Monday, May 26, 2003 - 11:57 am: | |
I studied the wiring diagram in the manual, and steve is right, that's a single condensor that spans the positive terminal for the running points to the earth side of the retarded idle points (earths through the microswitch). Since the two sets of points are in parallel, the first (normal looking) condensor actually protects both sets of points from arcing. The weird condensor seems to have no function when looking at the one distributor alone, but I suppose it may have some function that prevents the two distributors from sending each other signals. Too complicated for my 20 year-old electrical training to figure out. |
JohnR. (Rivee)
Junior Member
Username: Rivee
Post Number: 216
Registered: 1-2002
| | Posted on Saturday, May 24, 2003 - 4:18 am: | |
Hans,
Didn't know that. How would they trigger? |
Andrew A. Illes (Andyilles)
New member
Username: Andyilles
Post Number: 46
Registered: 10-2002
| | Posted on Friday, May 23, 2003 - 8:56 pm: | |
Russ,
Steve Magnussen has it exactly right. Stick with the proper F part, unless you go optical. WHY did F do it that way? Who knows.
Good luck,
Andy |
Hans E. Hansen (4re_gt4)
Intermediate Member
Username: 4re_gt4
Post Number: 1364
Registered: 4-2002
| | Posted on Friday, May 23, 2003 - 6:37 pm: | |
Actually, John, you can trigger the Crane 700s with points. The advantage is that the points will last nearly forever.
I don't know about the Ferrari distributor, but in an old Corvette that I had, high rpm point bounce and resulting misfiring of the spark was a real problem. That's why I'm glad that my car was converted to optical triggers. |
JohnR. (Rivee)
Junior Member
Username: Rivee
Post Number: 214
Registered: 1-2002
| | Posted on Friday, May 23, 2003 - 5:25 pm: | |
Steve,
I was just kidding about the points burning up.
Odviously there are no points in electronic ingn. |
Steve (Steve)
Member
Username: Steve
Post Number: 383
Registered: 2-2001
| | Posted on Friday, May 23, 2003 - 4:48 pm: | |
I don't have points , pertronix's is a way to go. |
JohnR. (Rivee)
Junior Member
Username: Rivee
Post Number: 213
Registered: 1-2002
| | Posted on Friday, May 23, 2003 - 1:08 pm: | |
Russ,
What Hans elaborated on is the way to go.
I changed mine from the 4 points setup to the duel Crane 700XP a year ago and haven't burnt even one set of points yet! |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 1809
Registered: 1-2001
| | Posted on Friday, May 23, 2003 - 10:31 am: | |
Russ -- The 308 condensor with two wire leads is not two separate capacitors built into one unit, but rather a single capacitor where the outer case is not hooked to one of the plates. If you got a single lead condensor of the same capacitance AND added a wire to the outer case AND mounted it so that the outer case was not grounded to the distributor housing, you would have a quasi-equivalent unit. If you replace the two-wire capacitor with a single wire capacitor and hook the single wire onto the existing R2 post you will have removed capacitance from across the R2 points (and added useless capacitance in parallel with the microswitch).
I think you're over-simplifying things a little in terms of the required "rewiring" as the the "R1" terminal on the Distributor is the "+" coming from the coil for the R1 points, but the R2 terminal on the distributor is not the coil lead for the R2 points. To have the R1/R2 stuff working and put a single wire external capacitor on the R2 point "+" side would require adding a third connection to the distributor housing (i.e., coil/cap for R1, coil/cap for R2, and R2 base -to- microswitch). Moreover, unless you've got an oscilloscope to verify what's actually happening in the coil primary winding I think you're asking for a little trouble -- JMOs... |
JRV (Jrvall)
Intermediate Member
Username: Jrvall
Post Number: 1539
Registered: 11-2002
| | Posted on Friday, May 23, 2003 - 5:31 am: | |
Normal single wire condensors work just fine.
|
Hans E. Hansen (4re_gt4)
Intermediate Member
Username: 4re_gt4
Post Number: 1356
Registered: 4-2002
| | Posted on Friday, May 23, 2003 - 1:34 am: | |
Works real easily. Switch to Crane optical triggers and electronic ignition.
If you're REAL stubborn, ask Rob Garven. I believe that he refuses to join the 20th century (even tho that has passed), and still uses the equipment you refer to.
FWIW, I *think* you can substitute 2 condensors for the one unit you have. And, you probably can do away with the retarded set of points, just keeping the 'running' points. |
Russ Gould (Russ)
New member
Username: Russ
Post Number: 14
Registered: 2-2003
| | Posted on Friday, May 23, 2003 - 12:08 am: | |
Anyone know why Mr Marelli decided he needed that weird double condensor (it's two separate units in one housing as best I can tell)...why not a plain single on each set of points and be done with it? In effect there are three condensors, R1 has one to itself plus a share of R2's, and R2 has the other half of the weird condensor.Anyone tried a simple setup with one normal condensor per set of points? How could this possibly not work? |