Dual-Point Dwell?

[Mike Bartlett]

I have a C5AE-H 427 S/O Block. I am trying to figure out what I should set my dual-point to. In a book I have my block number pulls up as a 65-66 427. So when I look up what my dwell angle should be I get as follows.

1965 V8-427 Conventional ignition 30-33 deg. Transistor ignition 22-24 deg. I am assuming mine is conventional being that it is a standard Ford dual-point?

1966 V8-427 22-24 deg. dwell angle.

So, any ideas as to what I should set my dwell at? I am checking them using a dwell meter. I am not blocking off one set of points then checking dwell. I am checking them together as a combined dwell.not

Thank You,

Mike
Pleasanton, CA

[Mike Bartlett]

I have a C5AE-H 427 S/O Block. I am trying to figure out what I should set my dual-point to. In a book I have my block number pulls up as a 65-66 427. So when I look up what my dwell angle should be I get as follows.

1965 V8-427 Conventional ignition 30-33 deg. Transistor ignition 22-24 deg. I am assuming mine is conventional being that it is a standard Ford dual-point?

1966 V8-427 22-24 deg. dwell angle.

So, any ideas as to what I should set my dwell at? I am checking them using a dwell meter. I am not blocking off one set of points then checking dwell. I am checking them together as a combined dwell.

Thank You,

Mike
Pleasanton, CA

[trularin]

As I recall, and this is on my boss dual point distributor, I have mine set at 30 total degree dwell. I use a SnapOn Tach&Dwell and a feedguage, not sure by I want to say .018.

Any one else remember this stuff?

[Excaliber]

Dwell readings on some distruibutors can be tough to get right, use a little common sense when setting it. A combination of dwell and a reality check of minimum point gap.

For instance if the dwell reading is 22-24 but the point gap is really small (.010 as an example) that just aint right! The point gap needs to be a minimum of .015-16 regardless of dwell reading. There are several things that can result in an inaccurate dwell reading.

[Ford of France]

Typically, each set of points is set individually. This is accomplished by blocking open one set of points while setting the other. In your case, a 26-28 degree dwell setting on each set of points should give you around 30 total dwell. The overlap is around 5 degrees once both set of points are set. Use a dwell meter and don't depend on a feeler gauge, if at all possible.

[ItBites]

Total should be the same whether two or one set of points is used.

[lovehamr]

On my Boss I use an MSD, lost one set of points and just set the one that's left to open and close. With the MSD; "We don't need no stinking dwell!" Of course that's only with an MSD, so it's just my two cents.
Steve

[Jerry Clayton]

I seem to remember that I used 25degrees each set of points with 33 degrees total. Don't block one set open as the dwell can't be set correctly unless there is spring pressure on the breaker cam like when it runs. Set one set of points so that they stay open ,keeping pressure on the cam. Set the other set to 25 degrees and then adjust the second set to the total of 33 degrees, which will be about 25 degrees separately. After a amount of time you will notice that only one set starts to burn, as the current across the set that breaks the dwell will have the arc.

Only on a 4 lobe rotor(such as a old Mallory) will each set and total be the same as each point is open longer than the other set is closed.

I have also used an Accel dual point that had the external wiring so you could disconnect one set while setting the dwell and then hook up the other to set the total. That worked nice but I wired up a switch so I could retard my timing by selecting either or both sets of contacts. This was way before all the ignition retards and such that are now available.

There was also a breaker cam in the 534 truck engine that only had 10degrees of advance making it possible to run more initial timing lead.

Can you believe that noone has used points for 30 years now?

Jerry

[Carnut427]

The advantage to dual points was the increased dwell angle, giving a hotter spark. Standard single points were set around 30*. What good would dual points do you if the total dwell was also only 30*? None, obviously. If you set your single points at 33* dwell, they wouldn't last long. And yes, when setting dual points, you set one set of points at a time, by putting a piece of cardboard or whatever in the second set, making them non-functional.

[Excaliber]

30 years? Has it been that long? Dang, I used to pay the rent adjusting points and changing spark plugs. That new fangled electronic stuff made me get out of wrenching.

[ffindling]

One advantage to using an electronic
ignition is that point dwell becomes meaningless. Popular electronic ignitions
like the MSD 6AL can be used with breaker
point type distributors. In those cases, the
points only act as a triggering source, the
actual "dwell" or saturation time of the coil
primary is determined by the module. Current draw across the points is minimal
so point life is more a question of mechanical wear than the contact button
life. So you can eliminate one set of points
and use the remaining one as a trigger
source. Of course, it would make sense
to use a "drop-in" magnetic trigger assembly like a Crane XR-I and be rid of
the points altogether.
Point type ignitions haven't been used
by OEM's for 30 years now as others have
mentioned and that's with good reason,
electronic systems are vastly superior.
If the "vintage" look is important, using
a "drop-in" conversion in a legacy distributor and mounting the module in
a hidden location should satisfy that.

....Fred

[Carnut427]

Originally posted by ffindling


...Of course, it would make sense
to use a "drop-in" magnetic trigger assembly like a Crane XR-I and be rid of the points altogether...
....Fred

Another alternative: Ford's electronic ignition will drop right into a Ford points distributor. The electronic ignition unit doesn't even have to be from an FE...one from ANY Ford V8 will bolt in. The only thing to look for is the control box must have a blue wire strain relief where the wires exit the control unit. Any other color signifies computer control or some other variance.

[Pete Wolff]

The proper dwell for your dual point would be 26 degrees each and 34 degrees total. I used to block the points one set at a time with a match book cover and adjust to the 26 degrees while cranking the motor.
Do yourself a favor and convert to a Pertronix module. No modification necessary to the dist and the car will start/run better. Conversion bact to points if needed in an emergency is simple

[Enginetime]

Throw out the points set and invest in a "hall-effect" sensor to trigger your ignition. Either Crane or Petronix kits for your distributor are fine. This is a must for serious performance.
MD

[Bryan Wilson]

I had an Accel dual point setup and it was a real pain in the a$$ to setup.
Would run alright for a while and then I would have to go through the re-tune exercise again.
Tossed it out and replaced with a reluctor/magnetic pickup distributor, electronic coil and a Deltamax electronic ignition module.
Engine now starts easier, has noticeably more power and better gas mileage.
Cheers,
Bryan