C1 1961 Shame on me!
01-22-2018, 08:47 PM
#1
Tether Man
Thread Starter
Member Since: Dec 2004
Location: Pittsburgh, South Hills
Posts: 4,539
Received 2,019 Likes
on
1,040 Posts
2023 C2 of the Year Finalist - Modified
2022 C2 of the Year Finalist - Unmodified
2019 C1 of Year Finalist (appearance mods)
C1 1961 Shame on me!
I just tonight noticed that my Accel 34100 Dual Point Distributor is only running one set of points! The (I'm assuming) secondary points were not even connected (no Wire)....
Question is: will the engine (283) run better with both point sets connected...or did the previous owner just have the second set in the distributor for a "spare".... WTH!!!
I'm getting ready to replace the points and reconnect both.....Man, how do you check on this stuff when you buy these " great old" Cars.
Any answers or comments are, as always, welcome!!
dcamick
Question is: will the engine (283) run better with both point sets connected...or did the previous owner just have the second set in the distributor for a "spare".... WTH!!!
I'm getting ready to replace the points and reconnect both.....Man, how do you check on this stuff when you buy these " great old" Cars.
Any answers or comments are, as always, welcome!!
dcamick
Last edited by dcamick; 01-22-2018 at 08:48 PM.
01-22-2018, 09:05 PM
#2
Team Owner
Dual point distributors' purpose was to increase dwell time...then, later on, it was discovered that didn't work any better than single points. Your car will prob run fine all day, every day with one working set of points.
The following users liked this post:
dcamick (01-22-2018)
01-22-2018, 09:14 PM
#3
Race Director
I've had my 62 for 40+ years, and I've never had a second set of points, in the factory dual point distributor. Back in the 70's, I had the distributor recurved, but that was usually one of the first things I did to every car I bought back then.
The following users liked this post:
dcamick (01-22-2018)
01-23-2018, 05:37 PM
#4
Race Director
From the web:
One point of clarification right up front: For those of you who bought a Mallory Dual Points distributor to have longer dwell for a hotter spark, you have been bamboozled, or are misinformed.
(irrelevant stuff snipped)
So if neither dwell nor open time is particularly important, you might ask why dual points may have any advantage. The answer is stability, durability, accuracy, and a certain ease or convenience of adjustment.
Contact points "wear" with use in various ways. The rubbing foot may wear down a bit, which brings the points closer together and increases dwell. The contacts may wear or burn away, which would make the points gap larger and decrease dwell. If the condenser is going bad or is the wrong capacitance value, points may transfer material from one to the other, leaving a pit in one side and a peak on the other side. This may increase or decrease dwell depending on the pattern of erosion and deposition. As dwell is increased the points open later and close earlier, and vice versa for less dwell. The closing time is not very important, but the opening time is, as this directly affects spark timing. In the interest of maintaining accurate spark timing, there is a vested interest to minimize changes of dwell, which leads to an interest in decreasing wear on the contact points.
With the dual points distributor, the first points set to close "makes" the circuit and will incur any ravages caused by a small amount of arcing when closing. The last points set to open "breaks" the circuit and will incur any ravages caused by a small amount of arcing when opening. Since the make and break functions are done by different contact sets, the two sets of points share the wear and each will therefore wear less with time, causing less variation of dwell and timing, and it can run longer between required adjustment or points replacement. Also the two contact sets can share the electrical current load most of the time, so there can be less heating of the contacts and/or rubbing foot. This reduction of running heat leads to less wear on the rubbing foot as well as the contacts. This may be even more important if you also install a high output ignition coil which draws more current, which may noticeably shorten the life of single points. If the points may last roughly twice as long in service (and they do), it may not be such an increased expense to replace two sets of points instead of one. The reduced labor or inconvenience may save considerably on cost and/or tinkering time.
There is another effect which makes adjustment easier. A change of points gap induces a change in spark timing along with change of dwell. With single points you set the contact gap first, then run the engine (or spin the distributor) to check dwell, then re-adjust the points (if necessary) to get the correct dwell. Then you may need to go back and check/reset the timing again, as the dwell adjustment could have changed the spark timing. With dual points you set the gap on both sets of points, then set the timing, which is controlled solely by the secondary points (which open last). Then if necessary you can change the dwell by adjusting the primary contact set, which will have no effect whatsoever on spark timing, so you don't have to reset timing after adjusting dwell.
End of webstuff.
Personally, i would just shove a Mallory Unilite or Pertronix breakerless in that dual pt dizzy and never have to worry about it again.
Doug
One point of clarification right up front: For those of you who bought a Mallory Dual Points distributor to have longer dwell for a hotter spark, you have been bamboozled, or are misinformed.
(irrelevant stuff snipped)
So if neither dwell nor open time is particularly important, you might ask why dual points may have any advantage. The answer is stability, durability, accuracy, and a certain ease or convenience of adjustment.
Contact points "wear" with use in various ways. The rubbing foot may wear down a bit, which brings the points closer together and increases dwell. The contacts may wear or burn away, which would make the points gap larger and decrease dwell. If the condenser is going bad or is the wrong capacitance value, points may transfer material from one to the other, leaving a pit in one side and a peak on the other side. This may increase or decrease dwell depending on the pattern of erosion and deposition. As dwell is increased the points open later and close earlier, and vice versa for less dwell. The closing time is not very important, but the opening time is, as this directly affects spark timing. In the interest of maintaining accurate spark timing, there is a vested interest to minimize changes of dwell, which leads to an interest in decreasing wear on the contact points.
With the dual points distributor, the first points set to close "makes" the circuit and will incur any ravages caused by a small amount of arcing when closing. The last points set to open "breaks" the circuit and will incur any ravages caused by a small amount of arcing when opening. Since the make and break functions are done by different contact sets, the two sets of points share the wear and each will therefore wear less with time, causing less variation of dwell and timing, and it can run longer between required adjustment or points replacement. Also the two contact sets can share the electrical current load most of the time, so there can be less heating of the contacts and/or rubbing foot. This reduction of running heat leads to less wear on the rubbing foot as well as the contacts. This may be even more important if you also install a high output ignition coil which draws more current, which may noticeably shorten the life of single points. If the points may last roughly twice as long in service (and they do), it may not be such an increased expense to replace two sets of points instead of one. The reduced labor or inconvenience may save considerably on cost and/or tinkering time.
There is another effect which makes adjustment easier. A change of points gap induces a change in spark timing along with change of dwell. With single points you set the contact gap first, then run the engine (or spin the distributor) to check dwell, then re-adjust the points (if necessary) to get the correct dwell. Then you may need to go back and check/reset the timing again, as the dwell adjustment could have changed the spark timing. With dual points you set the gap on both sets of points, then set the timing, which is controlled solely by the secondary points (which open last). Then if necessary you can change the dwell by adjusting the primary contact set, which will have no effect whatsoever on spark timing, so you don't have to reset timing after adjusting dwell.
End of webstuff.
Personally, i would just shove a Mallory Unilite or Pertronix breakerless in that dual pt dizzy and never have to worry about it again.
Doug
Last edited by AZDoug; 01-23-2018 at 05:39 PM.
The following users liked this post:
dcamick (01-24-2018)
01-23-2018, 06:52 PM
#5
Race Director
Member Since: Apr 2015
Location: Fresno California
Posts: 17,505
Received 3,443 Likes
on
2,113 Posts
My '61 came with a dual point Delco Remy distributor. Ran fine. I installed a single point '69 distributor because I wanted a vacuum advance. Runs even better. No need for a dual point set-up in these cars. But on the street, vacuum advance is a huge plus for mileage and overall driving quality.
The following users liked this post:
dcamick (01-24-2018)
01-23-2018, 08:29 PM
#6
Safety Car
Member Since: Apr 2000
Location: New York New York
Posts: 4,819
Received 1,126 Likes
on
553 Posts
2023 C2 of the Year Finalist - Unmodified
2023 C1 of the Year Finalist - Unmodified
My '61 came with a dual point Delco Remy distributor. Ran fine. I installed a single point '69 distributor because I wanted a vacuum advance. Runs even better. No need for a dual point set-up in these cars. But on the street, vacuum advance is a huge plus for mileage and overall driving quality.
Very well said. I did the same thing with my 2 x 4 61. I rotated the distributor 180 so the vacuum advance is under the shielding.
Joe
01-24-2018, 08:52 AM
#7
Tether Man
Thread Starter
Member Since: Dec 2004
Location: Pittsburgh, South Hills
Posts: 4,539
Received 2,019 Likes
on
1,040 Posts
2023 C2 of the Year Finalist - Modified
2022 C2 of the Year Finalist - Unmodified
2019 C1 of Year Finalist (appearance mods)
From the web:
One point of clarification right up front: For those of you who bought a Mallory Dual Points distributor to have longer dwell for a hotter spark, you have been bamboozled, or are misinformed.
(irrelevant stuff snipped)
So if neither dwell nor open time is particularly important, you might ask why dual points may have any advantage. The answer is stability, durability, accuracy, and a certain ease or convenience of adjustment.
Contact points "wear" with use in various ways. The rubbing foot may wear down a bit, which brings the points closer together and increases dwell. The contacts may wear or burn away, which would make the points gap larger and decrease dwell. If the condenser is going bad or is the wrong capacitance value, points may transfer material from one to the other, leaving a pit in one side and a peak on the other side. This may increase or decrease dwell depending on the pattern of erosion and deposition. As dwell is increased the points open later and close earlier, and vice versa for less dwell. The closing time is not very important, but the opening time is, as this directly affects spark timing. In the interest of maintaining accurate spark timing, there is a vested interest to minimize changes of dwell, which leads to an interest in decreasing wear on the contact points.
With the dual points distributor, the first points set to close "makes" the circuit and will incur any ravages caused by a small amount of arcing when closing. The last points set to open "breaks" the circuit and will incur any ravages caused by a small amount of arcing when opening. Since the make and break functions are done by different contact sets, the two sets of points share the wear and each will therefore wear less with time, causing less variation of dwell and timing, and it can run longer between required adjustment or points replacement. Also the two contact sets can share the electrical current load most of the time, so there can be less heating of the contacts and/or rubbing foot. This reduction of running heat leads to less wear on the rubbing foot as well as the contacts. This may be even more important if you also install a high output ignition coil which draws more current, which may noticeably shorten the life of single points. If the points may last roughly twice as long in service (and they do), it may not be such an increased expense to replace two sets of points instead of one. The reduced labor or inconvenience may save considerably on cost and/or tinkering time.
There is another effect which makes adjustment easier. A change of points gap induces a change in spark timing along with change of dwell. With single points you set the contact gap first, then run the engine (or spin the distributor) to check dwell, then re-adjust the points (if necessary) to get the correct dwell. Then you may need to go back and check/reset the timing again, as the dwell adjustment could have changed the spark timing. With dual points you set the gap on both sets of points, then set the timing, which is controlled solely by the secondary points (which open last). Then if necessary you can change the dwell by adjusting the primary contact set, which will have no effect whatsoever on spark timing, so you don't have to reset timing after adjusting dwell.
End of webstuff.
Personally, i would just shove a Mallory Unilite or Pertronix breakerless in that dual pt dizzy and never have to worry about it again.
Doug
One point of clarification right up front: For those of you who bought a Mallory Dual Points distributor to have longer dwell for a hotter spark, you have been bamboozled, or are misinformed.
(irrelevant stuff snipped)
So if neither dwell nor open time is particularly important, you might ask why dual points may have any advantage. The answer is stability, durability, accuracy, and a certain ease or convenience of adjustment.
Contact points "wear" with use in various ways. The rubbing foot may wear down a bit, which brings the points closer together and increases dwell. The contacts may wear or burn away, which would make the points gap larger and decrease dwell. If the condenser is going bad or is the wrong capacitance value, points may transfer material from one to the other, leaving a pit in one side and a peak on the other side. This may increase or decrease dwell depending on the pattern of erosion and deposition. As dwell is increased the points open later and close earlier, and vice versa for less dwell. The closing time is not very important, but the opening time is, as this directly affects spark timing. In the interest of maintaining accurate spark timing, there is a vested interest to minimize changes of dwell, which leads to an interest in decreasing wear on the contact points.
With the dual points distributor, the first points set to close "makes" the circuit and will incur any ravages caused by a small amount of arcing when closing. The last points set to open "breaks" the circuit and will incur any ravages caused by a small amount of arcing when opening. Since the make and break functions are done by different contact sets, the two sets of points share the wear and each will therefore wear less with time, causing less variation of dwell and timing, and it can run longer between required adjustment or points replacement. Also the two contact sets can share the electrical current load most of the time, so there can be less heating of the contacts and/or rubbing foot. This reduction of running heat leads to less wear on the rubbing foot as well as the contacts. This may be even more important if you also install a high output ignition coil which draws more current, which may noticeably shorten the life of single points. If the points may last roughly twice as long in service (and they do), it may not be such an increased expense to replace two sets of points instead of one. The reduced labor or inconvenience may save considerably on cost and/or tinkering time.
There is another effect which makes adjustment easier. A change of points gap induces a change in spark timing along with change of dwell. With single points you set the contact gap first, then run the engine (or spin the distributor) to check dwell, then re-adjust the points (if necessary) to get the correct dwell. Then you may need to go back and check/reset the timing again, as the dwell adjustment could have changed the spark timing. With dual points you set the gap on both sets of points, then set the timing, which is controlled solely by the secondary points (which open last). Then if necessary you can change the dwell by adjusting the primary contact set, which will have no effect whatsoever on spark timing, so you don't have to reset timing after adjusting dwell.
End of webstuff.
Personally, i would just shove a Mallory Unilite or Pertronix breakerless in that dual pt dizzy and never have to worry about it again.
Doug
I have a Accel (34100) Dual Point Distributor. It takes Ford Points.....
Do you have any input as to which Pertronix Breakerless unit I should put in this distributor?
This distributor carries no Vacuum, advance weights and runs with a Holley 650 Spread bore Carb on a 2101 Edelbrock Performer intake. Initial timing set at 10% BTDC.
Actually runs very well....
Doug Amick
01-24-2018, 09:30 AM
#8
Race Director
Member Since: Mar 2001
Location: Mustang OK
Posts: 13,852
Received 3,772 Likes
on
1,674 Posts
2023 C1 of the Year Finalist - Modified
2015 C1 of the Year Finalist
With all of the above said, keep in mind that the 63-65 solid lifter engines (the highest performance versions of that day) had gone from dual points to single points----------WITH VACUUM ADVANCE!!!!!! Gosh, I wonder why?
When I installed FI on a 350 in the 56, it had a 62 dual point, mechanical advance dist (NO vac adv). I ran it for several years that way and I always felt that it would run better on the street if the dist had vac adv. FINALLY, several years later, I swapped the 62 FI dist for a 65 FI dist. Night and day difference for city driving!!! That FI and dist is now on the SB400 with a much bigger profile cam and it still performs great.
When I installed FI on a 350 in the 56, it had a 62 dual point, mechanical advance dist (NO vac adv). I ran it for several years that way and I always felt that it would run better on the street if the dist had vac adv. FINALLY, several years later, I swapped the 62 FI dist for a 65 FI dist. Night and day difference for city driving!!! That FI and dist is now on the SB400 with a much bigger profile cam and it still performs great.
Last edited by DZAUTO; 01-24-2018 at 09:32 AM.
01-24-2018, 10:57 AM
#9
Race Director
As far as your Accel DPD, Call Pertronix and ask them.
This is an electronic points replacement, it has no bearing or effect on advance weights, ignition curve, carb, etc.
Doug
This is an electronic points replacement, it has no bearing or effect on advance weights, ignition curve, carb, etc.
Doug
The following users liked this post:
dcamick (01-24-2018)
01-24-2018, 12:20 PM
#10
Safety Car
Member Since: Jan 2000
Location: Poway CA
Posts: 4,845
Received 1,295 Likes
on
560 Posts
2023 C1 of the Year Finalist - Unmodified
2022 C1 of the Year Finalist - Unmodified
2021 C1 of the Year Finalist - Unmodified
2019 C1 of Year Finalist (stock)
2016 C1 of Year Finalist
If you are going to stay with points, I would fix it right.. Mainly for the 'redundancy and load sharing' benefits...
Otherwise, as some have said, go breakerless! If it were me I'd put your current dist. in storage and run a whole pertronixs distributor (module, weights, and vac advance)
Otherwise, as some have said, go breakerless! If it were me I'd put your current dist. in storage and run a whole pertronixs distributor (module, weights, and vac advance)
The following users liked this post:
dcamick (01-24-2018)
01-24-2018, 12:35 PM
#11
Single point dissy all you need. The people at the points vendor asked how can we make more money. I know, make a false report that 2 points are better then one. There are plenty of fish that will bite.
01-24-2018, 05:00 PM
#12
Race Director
Member Since: Mar 2001
Location: Mustang OK
Posts: 13,852
Received 3,772 Likes
on
1,674 Posts
2023 C1 of the Year Finalist - Modified
2015 C1 of the Year Finalist
Going with something other than a Delco Remy distributor is fine. Although, I prefer to use a Delco that has been rebuilt to like new condition plus an electronic conversion.
BUUUUUUUUUUUUUT, if the engine has a Rochester FI unit, then you're locked into a Delco FI dist.
BUUUUUUUUUUUUUT, if the engine has a Rochester FI unit, then you're locked into a Delco FI dist.
01-24-2018, 08:46 PM
#13
Team Owner
Member Since: Jan 2007
Location: Southern Cal Ca
Posts: 50,468
Received 762 Likes
on
613 Posts
St. Jude Donor '22
i run dual in my mustang
i thought the idea was less float at higher rpms
can be a pain to gap and get the required dwell.
tickle one set and nudge the other
i thought the idea was less float at higher rpms
can be a pain to gap and get the required dwell.
tickle one set and nudge the other
02-02-2018, 08:20 AM
#14
Tether Man
Thread Starter
Member Since: Dec 2004
Location: Pittsburgh, South Hills
Posts: 4,539
Received 2,019 Likes
on
1,040 Posts
2023 C2 of the Year Finalist - Modified
2022 C2 of the Year Finalist - Unmodified
2019 C1 of Year Finalist (appearance mods)
As a followup to my post...I have purchased a Pertronix Distributor and replaced my DP Accel.
Fixed a few wires in the process. Pushed the Ignition coil away from the new dizzy. Set total timing @ 36 degree @2300 RPM. Initial timing @ 10 degree BTDC. Also connected the Vacuum advance (which I did not have with the dual point Accel).
Starts and runs a lot better....but will wait till the snow melts before road testing.
Thanks for all the help!
Have a Great Super Bowl Weekend! Being from Pittsburgh.... not too interested in either of these teams.
Fixed a few wires in the process. Pushed the Ignition coil away from the new dizzy. Set total timing @ 36 degree @2300 RPM. Initial timing @ 10 degree BTDC. Also connected the Vacuum advance (which I did not have with the dual point Accel).
Starts and runs a lot better....but will wait till the snow melts before road testing.
Thanks for all the help!
Have a Great Super Bowl Weekend! Being from Pittsburgh.... not too interested in either of these teams.
02-02-2018, 01:37 PM
#15
Race Director
Member Since: Apr 2015
Location: Fresno California
Posts: 17,505
Received 3,443 Likes
on
2,113 Posts
Snow melting? It's 70 degrees here. I'll be running errands in the '61 this weekend!
02-02-2018, 06:14 PM
#16
Tether Man
Thread Starter
Member Since: Dec 2004
Location: Pittsburgh, South Hills
Posts: 4,539
Received 2,019 Likes
on
1,040 Posts
2023 C2 of the Year Finalist - Modified
2022 C2 of the Year Finalist - Unmodified
2019 C1 of Year Finalist (appearance mods)
02-03-2018, 01:00 PM
#17
Burning Brakes
Member Since: Jun 2005
Location: Hinesville, GA & Oswego, NY
Posts: 793
Received 215 Likes
on
136 Posts
In my 427 Ford I have a Mallory distributor that has a 4 lobe cam and uses 2 sets of points and 2 large external mounted condensers, I set it up in my sun distributor machine and it stays dead on for long time, points last about 5 times as my vette points.
I also have one for a small or big block Chev. I have it set up at 26 degrees at 2100 RPM, however I have never used as long as my original set up runs as good as it does I am not going to try to "fix" it.
Bill
I also have one for a small or big block Chev. I have it set up at 26 degrees at 2100 RPM, however I have never used as long as my original set up runs as good as it does I am not going to try to "fix" it.
Bill
Last edited by Bill Pilon; 02-03-2018 at 02:32 PM.