My old school 340 upgrades and results.

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340dartley said:
I believe the problem was there before the box. I have not thrown any parts on it as of yet. It is still a fun car to drive right now. If it had single valve springs then I could stay with the worn valve spring theory. Seeing the doubles with a damper inside makes me think they should be overkill even if worn out a bit. Mopar specs a single valve spring as one that goes with the cam. It is no longer available though. I really think we are going to find either a pick up coil problem or a rotor phasing problem.
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Any progress with the feeler gauge and checking the pickup and such? I'm curious what it turns out to be.
 
Not yet. Just got off work and heading home. Probably will check later tonight . My daughter has a 4h meeting tonight so will be delayed
 
I just went out to check it the car tonight. I found a couple of things. Nothing that seemed to make a difference. The phasing did seem off by quite a ways. The clocking of the distributor drive gear was off a couple teeth from factory. I reset and reinstalled the distributor. One problem. The tach drive now hits the intake . I disconnected the tach drive and set my timing at 34. Cranked it up still breaks up at high rpm. Didn't have a tach so was doing it by ear. I bumped the timing up to 40 by accident. It liked this for idling but didn't help the breaking up. I forgot to bring my vacuum Guage home so will try that tomorrow. Oh and the reluctor gap was .008
 
Oh and I managed to break my tach drive coupler while trying to rerout it around the stock coil mounting boss
 
This one too has my curiosity. I'm waiting to see some simple fix and Off to the Races and quite possibly that 11-2 that's in the car that was supposedly there before? I mean really if you had another 1500 RPM in each gear then we're able to reach some kind of torque curve who knows....
 
I may try to barrow another electronic distributor. Talking to a guy at work who has a 71 Chevy Camaro. He uses an aftermarket ignition that uses a Chrysler pickup coil. He mentioned that his pick up coil connection was backwards and he would run fine until high rpm then start breaking up. I will check that also.
 
I wish you lived close I just bring my shoebox over that has my distributor wires ignition box coil and ballast resistor still hooked up to each other and put it on your car and see if that cures it and done. I just ran an 11-5 and it no problem. Took it off and did an all MSD.
 
340dartley said:
I just went out to check it the car tonight. I found a couple of things. Nothing that seemed to make a difference. The phasing did seem off by quite a ways. The clocking of the distributor drive gear was off a couple teeth from factory. I reset and reinstalled the distributor. One problem. The tach drive now hits the intake . I disconnected the tach drive and set my timing at 34. Cranked it up still breaks up at high rpm. Didn't have a tach so was doing it by ear. I bumped the timing up to 40 by accident. It liked this for idling but didn't help the breaking up. I forgot to bring my vacuum Guage home so will try that tomorrow. Oh and the reluctor gap was .008
Click to expand...


You can't clock the drive gear by a factory anything. You look at where the slot is when the rotor is pointing at number 1 on the cap. Then you clock the drive gear. Otherwise, you break the tach drive off, or the vacuum advance can if for some reason you think you should have one.
 
yellow rose said:
You can't clock the drive gear by a factory anything. You look at where the slot is when the rotor is pointing at number 1 on the cap. Then you clock the drive gear. Otherwise, you break the tach drive off, or the vacuum advance can if for some reason you think you should have one.
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The problem was when I rotated the timing mark approx 34 degrees before TDC the rotor was actually closer the number 8 terminal than the number 1 terminal. I was attempting to get the rotor closer to number 1 to prevent spark jump.
 
Reversal of the reluctor connections usually shows up as erratic timing... does the timing change in any odd ways on your timing light while slowly revving it up, and with the vacuum advance plugged?
 
Timing doesn't change at all. There is no vacuum advance on this distributor.

Also I should clarify. The distributor advance is not actually locked per say. The springs are so light that it is all in at idle speeds. For my testing with a timing light it is 34 at idle and at WOT
 
340dartley said:
The problem was when I rotated the timing mark approx 34 degrees before TDC the rotor was actually closer the number 8 terminal than the number 1 terminal. I was attempting to get the rotor closer to number 1 to prevent spark jump.
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I've cut the top off an old cap before just to see where the rotor was pointing when it was firing. Amazing where some Dizzy's are pointing.
 
if the rotor is closer to the #8 wire move the wires over 1 notch in the cap. and as was said, the drive gear alignment is an aid for some, but U can have it anywhere U need it to be. do a rough measurement of a few valve springs installed height-if it is high for the springs-load will be low. also may have too much lifter preload
 
340dartley said:
Timing doesn't change at all. There is no vacuum advance on this distributor.

Also I should clarify. The distributor advance is not actually locked per say. The springs are so light that it is all in at idle speeds. For my testing with a timing light it is 34 at idle and at WOT
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Roger. I would not be suspecting reluctor reversal with steady timing.
 
Could the trigger wheel be installed in the other direction keyway?

Distributor doesn't care where #1 is in the cap, as long as it's correct firing order. Try putting an MSD distributor in a car using the factory drive clocking orientation... GOOD LUCK!!!
 

I have a factory electronic distributor coming tomorrow. Should just drop right in and plug in.
As far as the distributor not caring where number 1 is. It doesn't. The issues that sometime happen have to do with rotor phasing. Rotating the distributor back and forth adjusts timing by changing the reluctor to pickup relationship. The problem occurs when the rotor is close enough to the next terminal that spark can jump to the wrong spot. I was trying to change that but after thinking about it for a bit I realize that my reclocking the drive gear did nothing. Since I am running all my timing in at such a low rpm I can figure out where I want my rotor to point and lock in my mechanical advance at that spot. All this and I am not sure that this is the cause of the problem.

I could also retard my timing several degrees and see if it still breaks up on top.
 
Not doing much on the car tonigh . Removed the tach drive cable so I can get it fixed.
I rechecked my reluctor gap and it is .006 to.007. I will open it up tomorrow. Wife wants to hang out lol
 
I actually used a stock distributor for the last couple years and just blocked off the vacuum advance and used only that centrifical advance. it worked almost exactly the same as the MSD. Now the MSD setup the starts better and stuff like that but I don't think I gained anything in the quarter mile that I can see so far. I was going to suggest an inexpensive stock distributor but I have a hard time cyber spending other people's money. But I agree this is a good starting point and not that expensive. I think I paid like $68 Maybe for mine brand new.
 
j par said:
I actually used a stock distributor for the last couple years and just blocked off the vacuum advance and used only that centrifical advance. it worked almost exactly the same as the MSD. Now the MSD setup the starts better and stuff like that but I don't think I gained anything in the quarter mile that I can see so far. I was going to suggest an inexpensive stock distributor but I have a hard time cyber spending other people's money. But I agree this is a good starting point and not that expensive. I think I paid like $68 Maybe for mine brand new.
Click to expand...

I did the same in my setup. I ran the stock reman/recurve I have with my box. I have a new distributor now, but it's still the old mopar/mallory style. Nothing wrong with them. They work great. I doubt you'd give up anything to an MSD in the quarter. With breakup distributor is always a good bet. And if it isn't that. Well hell you can always use a spare around the shop anyways.

Try the gap at 8-10, make sure the rotor is phased correctly. And let us know. I am still very interested in what is causing this.
 
Lustle said:
I did the same in my setup. I ran the stock reman/recurve I have with my box. I have a new distributor now, but it's still the old mopar/mallory style. Nothing wrong with them. They work great. I doubt you'd give up anything to an MSD in the quarter. With breakup distributor is always a good bet. And if it isn't that. Well hell you can always use a spare around the shop anyways.

Try the gap at 8-10, make sure the rotor is phased correctly. And let us know. I am still very interested in what is causing this.
Click to expand...
The distributor I found on Craigslist locally. He is selling it for 30 and it was originally part of a kit. He told me that he is using an MSD distributor now.
I could use having a spare even if it doesn't fix it.
 
Ok I got me a new to me distributor. It looks brand new. It already has the light advance springs. The shafts on top is brass. Not a spec of dirt on it. The previous owner said he had it in his Duster with a 408. He changed to a different ignition set up. Only issue was one of the cap retention clips was missing. Picked one up from a wrecking yard at lunch for 3 dollar . Cap was junk. Looked like it arched through the top terminal. Bought a new cap and rotor. Should be ready to drop in and fire now. Can't wait to get off work and go work in the car. I also picked up my mopar performance auto meter tach with shift light from storage yesterday. Was in my 68 Plymouth Satellite that has a blown motor. It won't be using it for a little while
 
Nice! Is it the Mallory made dist with adjustable advance? Either way its cheap way to test and have a back up dist.
 
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