Ignition dwell and adjusting it.

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1994redram

1994redram

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I have a 1970 dart that had a slant 6. Bought the car and it had been sitting for 18 years. A new battery and some oil down the in cylinders had it cranking over well but no fire. I found the wire between the points and coil had been consumed by rodents. So i pulled the distributor replaced the wire, lightly sanded the points and she ran great for about 25,000 miles with absolutely nothing more than oil changes. That is the extent of knowledge I have with points.

I've pulled the slant and swapped it for a 5.9 magnum. Along with the engine swap I installed a edelbrock air gap and used 1406 carb, MSD coil, Doug's headers, and 2.5 inch dual exhaust. Trans is a stock 727 with a shift kit. I had a V8 dart parts car and ended up using the points distributor. I replaced the points, condenser, and vacuum advance. The car starts, runs and drives alright. The carb needs some work and seems to run rich at idle no matter how it's adjusted. But drives fine.

But in the back of my head I keep thinking I REALLY should set the points properly. I dont know the first thing about setting them. There has to be a better way than eyeballing them. So what equipment do I need and how do I go about doing it? And is there any performance to be gained if the car already runs as is?

P.S. I know points are outdated and electronic ignition is better. But they worked for decades and were reliable on my slant. So theyll work for now.
 
A dwell meter is best. The spec is 28-32 degrees of dwell. Hook the meter up with black to ground and the red or green wire to the negative side of the coil.

Remove coil wire so it will not start. Remove the distributor cap and rotor. Have someone spin the engine and watch the meter. It will register dwell in degrees while spinning. It if needs adjusting, loosen the adjusting screw and adjust the points using a flat blade screwdriver in the adjustment slot in the breaker plate to either open or close the point gap. Zero in on 28-32 degrees while the engine is spinning and lock it down. Put it back together. Done.
 
If you have a set of feeler gauges set at .017. Then check the dwell with a meter. This should get you close to 28-32 degrees.
 
RustyRatRod said:
A dwell meter is best. The spec is 28-32 degrees of dwell. Hook the meter up with black to ground and the red or green wire to the negative side of the coil.
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I have a multimeter that I think has a dwell selection on it. Is that all that's necessary? I also have feeler gauges. I'll set it with those and then check it with a meter for the sake of learning how. If there is in fact a specific ignition dwell meter needed. Can I get a decent one at Oreillys or Autozone?
 
1994redram said:
I have a multimeter that I think has a dwell selection on it. Is that all that's necessary? I also have feeler gauges. I'll set it with those and then check it with a meter for the sake of learning how. If there is in fact a specific ignition dwell meter needed. Can I get a decent one at Oreillys or Autozone?
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I doubt your volt meter has a dwell meter. Since the use of points has all but disappeared, finding a new dwell meter may not be easy. Flea markets or swap meets is where I see them the most now days.
 
A few "automotive" multimeters DO have dwell. Also don't forget to apply a tiny amount of grease to the side of the distributor cam "approaching" the points to keep the rubbing block lubed. REcheck dwell and timing after a couple hundred miles, they tend to "wear in." Set timing after you set the points
 
1994redram said:
I have a multimeter that I think has a dwell selection on it. Is that all that's necessary? I also have feeler gauges. I'll set it with those and then check it with a meter for the sake of learning how. If there is in fact a specific ignition dwell meter needed. Can I get a decent one at Oreillys or Autozone?
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Yes, you should be able to find one.
 
This is an "acquired taste" and I'm out of practice. In the old days I never used a feeler. I just "roughed in" the dwell "on the starter" then buttoned up the cap and re-checked it "running." After a few times, you get the feel for how much correction to dial in. Also you want it on the "wide" side (28 degrees instead of more toward 30) again because the points "wear in" towards closed.

Also, with points you need a good condenser. Will not start/ run without one
 
67Dart273 said:
This is an "acquired taste" and I'm out of practice. In the old days I never used a feeler. I just "roughed in" the dwell "on the starter" then buttoned up the cap and re-checked it "running." After a few times, you get the feel for how much correction to dial in. Also you want it on the "wide" side (28 degrees instead of more toward 30) again because the points "wear in" towards closed.

Also, with points you need a good condenser. Will not start/ run without one
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AND with that : If the one you have fires , try it . The quality of ignition parts for vintage parts ,have gone downhill. Might think about a Pertronix 1 conversion, or one of these...
 
Abodybomber said:
AND with that : If the one you have fires , try it . The quality of ignition parts for vintage parts ,have gone downhill. Might think about a Pertronix 1 conversion, or one of these...
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Converts a 4 pin GM HEI module, to fit a stock Mopar small block distributior.
Also look at Greg / " Trailbeast " 's system conversion. It doesn't look stock , but it performs better.
The best part about Trailbeast : He just did a mild Magnum 5.9 /360 swap carbed .My thoughts are there . Have a good weekend.

20171209_235523.jpg
 
Points quality and condensers are really lacking, as over the counter go keep away from the bargain ones like airtek, try to find standard (blue streak) , delco, or better yet accell, Seems Condenser fail is getting really bad with the new ones, why I do not know. If all else fails let me know I have a lot of old NOS from the days and I can hook you up, and yes there are digital all in one meters out there, I have one that has tach/dwel along with all the other usual features, found it on fleabay and it was under 40, works really well, can find a pic if needed.
 
If the distributor is worn out ( and it probably is ) its a waste of time and money. The short story of my very 1st slant 6 about 40 years ago... Standard ignition tune up, carb rebuilt, valves adjusted, then new timing chain/set. Tried everything and it still didn't run perfect. A reman'd distributor cured it.
 
Distributor is good and tight. Parts car was low mileage but very rusty and had been vandalized. I bought and always try to buy the "premium" parts. Can't remember the brand but its whatever oreillys had.

I helped a friend put a pertronix conversion on his jeep cj years ago. It worked great but his points worked fine also at the time. He just wanted some extra reliability off road.

I plan on going EFI in the next year. Most of them require a special distributor to control timing. So using this OE distributor in the meanwhile is saving me a couple bucks. And learn something at the same time. My multimeter does have a dwell setting, so I'll use that and see what happens. But I'll stop by the parts store and try to buy a dedicated dwell meter. Thanks for all the help!
 
If you just set the point gap with a set of feeler gauges, the dwell should be where it needs to be.
 
Back in the day we used match book covers for a quick and easy points setting...easier to find an actual dwell meter than matches these days.
I use points on all of my cars..single for the drivers, dual for the hot rods.
Actually just picked up a Mallory Dual point yesterday to convert my 73 Roadrunner away from electronic.
Quality of points has not changed much over the years, but condensers are another story entirely. I recommend that if you do stick with points, try to create a stash of old condensers. Lately, half of the ones I have bought new are toast right out of the box
 
X2 you cannot buy a good condenser anymore.
I just changed my 48 willys to electronic this spring because of the condenser issue.
 
My friend bought a small block mallory dual point distributor at an estate sale awhile back. I could always borrow that for awhile and thought about it. But I'm not sure why I would even need such a thing for a cruiser.
 
Reality is just adjust what have, set it with feeler gauges.
 
Abodybomber said:
Converts a 4 pin GM HEI module, to fit a stock Mopar small block distributior.
Also look at Greg / " Trailbeast " 's system conversion. It doesn't look stock , but it performs better.
The best part about Trailbeast : He just did a mild Magnum 5.9 /360 swap carbed .My thoughts are there . Have a good weekend.

View attachment 1715119486
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I know Nate personally, he's a cool guy with a beautiful Mopar. Those HEI modules can be hidden anywhere there is a flat ground to mount them to. Dwell is the amount of time the coil is charging, Its hard to visualize how the gap and dwell can be individually changed without reworking the lobe profile of the distributor, dual points overlap so as to increase the dwell time.
 
sireland67 said:
X2 you cannot buy a good condenser anymore.
I just changed my 48 willys to electronic this spring because of the condenser issue.
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..........Probably not from automotive sources. I have not looked into a specific replacement because I'm not interested in breaker points. You SHOULD be able to determine the "typical value" of a vintage condenser and find a good quality replacement from an electronics supplier like Digikey or Mouser Electronics. You would need the right "type" to be effective and robust, heat, etc
 
If you try to get quality parts, then you most likely got the Borg Warner ignition parts from O'Reilly. They are pretty good for store bought parts.

1994redram said:
Distributor is good and tight. Parts car was low mileage but very rusty and had been vandalized. I bought and always try to buy the "premium" parts. Can't remember the brand but its whatever oreillys had.

I helped a friend put a pertronix conversion on his jeep cj years ago. It worked great but his points worked fine also at the time. He just wanted some extra reliability off road.

I plan on going EFI in the next year. Most of them require a special distributor to control timing. So using this OE distributor in the meanwhile is saving me a couple bucks. And learn something at the same time. My multimeter does have a dwell setting, so I'll use that and see what happens. But I'll stop by the parts store and try to buy a dedicated dwell meter. Thanks for all the help!
Click to expand...
 
sireland67 said:
If you just set the point gap with a set of feeler gauges, the dwell should be where it needs to be.
Click to expand...

Yes, as long as he makes SURE the feeler gauge is in straight and not tilted at all. That's why I recommend a dwell meter. They are cheap enough and if he's going to keep using points, he will be ahead of the game.

But you're 100% right. Nothing wrong with feeler gauges as long as you're careful.
 
Stopped in at oreillys and bought a nice Bosch multimeter as it has a dwell setting for 4,6 and 8 cylinder engines. My meter has a dwell setting only. So instead of chancing it, I upgraded! Also has a sweet RPM setting. Hooked it up and finally managed to set the dwell to 28. Reset the timing to 15 or so degrees and removed the carb to clean and blast the passages out. It runs MUCH better. Idles better, doesn't bog on wide open throttle and feels a bit quicker. But after tearing up some back roads and playing around I seem to have messed the trans up.... so I'll tear into that next weekend when I come home.
 
Well that is good to hear. Glad you got it running good. Now about that transmission issue! If it ain't one thing it's another!
 
I love this site! Where else can you find a bunch of guys who even know what dwell is? To summarize- pre-set points with feeler gauge at .016-.017. Fire engine and confirm dwell at approximately 30 degrees. Remember that any change in dwell changes timing, so always end by checking timing.
 
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