Why dual points?

No, a quick lookup says it's to increase the dwell (time between firing the plugs) and thus increase the coil rest time.

Your best bet will be to have a reliable modern car for everyday use saving the C-body for special occasions and weekend use as its around 50 years since such cars were suitable daily drivers.
 
Wow! Tachometer drive. Nice Museum piece or rat rod part. Obsoleted by electronic ignitions.
 
Your best bet will be to have a reliable modern car for everyday use saving the C-body for special occasions and weekend use as its around 50 years since such cars were suitable daily drivers.

Did I miss something where that was part of the question?
 
OP is having engine issues and I am assuming fishing for solutions and is intending to use his 68 Fury as a daily driver.
He ha a thread here about it
First day out with Sport Fury. Not the best.

I read it. What a train wreck.

My gawd do I feel sorry for the neophyte who must rely upon message boards.

My serious advice for the OP would be to join this message board...

The H.A.M.B.

...for general mechanical issues and use this forum to chase down specific trim parts or to BS.
 
Nope. Assumption incorrect. You know what they say about assumptions. I was just curious about the purpose of dual points. Something I never heard of before.

A train wreck it may be, but it's my train wreck. Car was headed for a crusher when I decided to buy it.

Yup. Daily driver. I have no interest in owning something I can't or don't use. I'm not running a museum.

Thanks for positive thoughts.
 
No, a quick lookup says it's to increase the dwell (time between firing the plugs) and thus increase the coil rest time.
That's not entirely true... I think the dual point distributers were developed along with the original hemi engines. My '53 331 and '54 354 both had dual points. I believe the thinking was to give a longer spark because of the size of the domed Hemi head engines they wanted a longer burn for more power and a complete burn of the fuel mixture. They open up to fire the plugs just a whisker after one another. Os a side effect the result was an awesome smoothness to boot. If you ever get a chance get in, or even hear an original Hemi engine run... It is AWESOME!
 
Judging by the cap and grease fitting, that's a Mallory dual point. Cool piece for a period restored race car, but kind of worthless for anything else. I think that's probably a smoking good price for someone looking for one... But that someone is few and far between. IIRC, this distributor will also have an adjustment for total mechanical advance.

The dual point distributor functions by having one set of points make the circuit and one set break the circuit. Any arcing of opening is then taken by one set and the same for closing. That gives you better point wear and a more stable dwell time. Usually there is also an increase in dwell time so the ignition coil has more time to charge. In theory, that should give you a more reliable spark, especially at higher RPM.
 
01414_g6qAwd37hfL_1200x900.jpg


danger-will-robinson.jpg


kinda 'splains it all!

:lol:
 
I read it. What a train wreck.

My gawd do I feel sorry for the neophyte who must rely upon message boards.

My serious advice for the OP would be to join this message board...

The H.A.M.B.

...for general mechanical issues and use this forum to chase down specific trim parts or to BS.
The HAMB doesn't allow our kind there.

If you've come here to discuss anything other than Hot Rods or Customs built in a style representative of 1965 or before, you've come to the wrong forum."
 
Aside from knowledgeable and helpful members, unsolicited opinions and off topic comments add to this board's uniqueness and popularity. Our motto should be if you are thin skinned you've come to the wrong forum. My .02.
 
Aside from knowledgeable and helpful members, unsolicited opinions and off topic comments add to this board's uniqueness and popularity. Our motto should be if you are thin skinned you've come to the wrong forum. My .02.

No thin skin here. I respond in the same vein I'm spoken to . That's why I don't use an alias. I'm as real here as in person and if I type it here it's something I would say to to you personally.
 
Joseph, As someone who has owned since the early '90's and still owns a number of '68 Furys (along with other C Body's) feel free to reach out to me with any questions. Hang in there. These cars can be made to be very reliable.
 
The points are slightly out of sync with each other. Any time both sets are closed current is running through the coil creating a magnetic field, more time current is running the bigger the field, at high rpm this time is limited. With normal single point the time the wiper is riding up the cam till it finally gaps enough to shut off current is dwell time that may be wasted at high rpm, The gap may not be wide enough on a single system to get a good field collapse, because the cam peak is passing by so fast at 3000+ rpm distributor speed (1/2 crank rpm) times this by 8 peaks on the cam, one can see how a single can get overwhelmed in a HP situation.
Dual points usually can get away with smaller gap and still provide good field collapse because of the more redundant chance to break the current flow with 2 switches/points.
Hope that makes sense, and yes their advantage only shows up in high rpm ignition stability. They do nothing but add complexity at 2500-3000 rpm. If it was to fix a problem at low rpm there is something wrong with your single point dist..
Remember there is no magic bullet in ignition systems, it fires the cylinder or it doesn't.
 
Interesting comments on the reasons for dual points.

I just remember it was developed for high rpm use and eliminate point floating resulting in short dwell times

It’s also harder on the cam lobes which was attributed to the higher spring tensions required to reduce bouncing points if memory serves me correctly still :rolleyes:
 
The HAMB doesn't allow our kind there.

If you've come here to discuss anything other than Hot Rods or Customs built in a style representative of 1965 or before, you've come to the wrong forum."

That's funny... I don't really hang out there, but I've read enough of their threads to see they tend to diagnose problems as opposed to throwing parts. I imagine that's because of the prohibition on whiz-bang shinola post 1965, but I didn't know it was an actual policy.
 
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