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Detail Question on Plug Wire location on a Prestolite DP Distributor on Hemi

Dragon Slayer

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Reviewing a ton of pictures on the Web for Stock 426 hemi cars I see a lot of different orientations of the distributor and wire location on the cap.

If you follow the Manual procedure for timing the Distributor you do wind up with the Prestolite Vacuum chamber pinched between intake manifold and fuel lines.

I have seen distributor VC behind fuel lines, and in front. I have seen Plug 1 wire and various locations, several cap slots different.

This is not an actual timing issue. The distributor only moves 5-8 degrees to get 10-16 degrees initial timing.

The manual does not give you a diagram for wire location on the cap. Just the firing order.

Part of the issue is that there are many variation to Prestolite DP shaft clocking (Orientation of the engagement slot on shaft), different Cam stop flat orientation which drives what direction the rotor points.

With many of these distributors being rebuilt or purchased as rebuilt back in the day you may not have original internal parts and the clocking is off.

So does anyone know what the orientation was from the Factory for the 68/69 hemi cars?
Looking at generic Motor Manuals they show that the 1 and 8 plug should straddle the fwd cap clip on Big Block engine, but no distinction made between Chrysler or Prestolite distributors.
 
Reviewing a ton of pictures on the Web for Stock 426 hemi cars I see a lot of different orientations of the distributor and wire location on the cap.

If you follow the Manual procedure for timing the Distributor you do wind up with the Prestolite Vacuum chamber pinched between intake manifold and fuel lines.

I have seen distributor VC behind fuel lines, and in front. I have seen Plug 1 wire and various locations, several cap slots different.

This is not an actual timing issue. The distributor only moves 5-8 degrees to get 10-16 degrees initial timing.

The manual does not give you a diagram for wire location on the cap. Just the firing order.

Part of the issue is that there are many variation to Prestolite DP shaft clocking (Orientation of the engagement slot on shaft), different Cam stop flat orientation which drives what direction the rotor points.

With many of these distributors being rebuilt or purchased as rebuilt back in the day you may not have original internal parts and the clocking is off.

So does anyone know what the orientation was from the Factory for the 68/69 hemi cars?
Looking at generic Motor Manuals they show that the 1 and 8 plug should straddle the fwd cap clip on Big Block engine, but no distinction made between Chrysler or Prestolite distributors.
As long as you have the wire on the correct order....The routing only affects overall appearance on the distributor cap. There is no one set way nor a diagram. OE judges would not factor that into play.
 
Thanks and good to know, but I am still interested in what is OEM. With DP distributors going for high dollars, and some with no tags, your either paying for the tag only, or it is fools money if the guts are not original. If Mopar times the distributor gear correct when building the hemi, and the distributors where all manufactured the same there would be only one correct placement for Plug wire 1.
 
Thanks and good to know, but I am still interested in what is OEM. With DP distributors going for high dollars, and some with no tags, your either paying for the tag only, or it is fools money if the guts are not original. If Mopar times the distributor gear correct when building the hemi, and the distributors where all manufactured the same there would be only one correct placement for Plug wire 1.
Plus wire one is per service manual.....as far as routing....how many shifts? How many line workers? How many plants?

Shoe me a judge or a judged car that got dinged on this?

I get your point but just follow number one position and go counter clockwise with every wire....
 
RB plug wire number one is before the distributor cap retainer clip, away from the VC and facing the alternator. That is how I set them. Hot Rod did mopar engine detailing article that depicts this as well. I would imagine it is the same on a hemi using a presotlite versus a 440 6 using the same distributor. I have attached a picture and while I do realize its not a hemi and not a prestolite dist, I am pretty sure its the same routing.

View attachment 564475

440-distributor1.jpg
 
RB plug wire number one is before the distributor cap retainer clip, away from the VC and facing the alternator. That is how I set them. Hot Rod did mopar engine detailing article that depicts this as well. I would imagine it is the same on a hemi using a presotlite versus a 440 6 using the same distributor. I have attached a picture and while I do realize its not a hemi and not a prestolite dist, I am pretty sure its the same routing.

View attachment 564475
It is the same.....Number one on a BB is the same position for ALL distributors
 
Thanks and that is how the Motor Reference books show it. Before the clip. The clip on Chrysler distributor are in a different position though. Further clockwise because vc is used as notch for the Chry cap. Prestolite cap and clip position is different.

Got the whole shift thing, but that would only create a 180 shift on cap position. Unless the motor builder did not time distributor gear right. Ultimately that could lead to lots of issues further down the assembly line. Regardless, once you FOLLOW the manual they should theoretically end up in the same spot. Physics of the parts mandate that. So a 180 out I can see, but shifted one or 2 plug holes means some part in the distributor is different from stock, or the motor timed not to standard.
 
Thanks and that is how the Motor Reference books show it. Before the clip. The clip on Chrysler distributor are in a different position though. Further clockwise because vc is used as notch for the Chry cap. Prestolite cap and clip position is different.

Got the whole shift thing, but that would only create a 180 shift on cap position. Unless the motor builder did not time distributor gear right. Ultimately that could lead to lots of issues further down the assembly line. Regardless, once you FOLLOW the manual they should theoretically end up in the same spot. Physics of the parts mandate that. So a 180 out I can see, but shifted one or 2 plug holes means some part in the distributor is different from stock, or the motor timed not to standard.

Uhmm all you need to do then is rotate the oil pump drive a few degrees if you are really picky about your distributor cap positioning.
 
Thanks and that is how the Motor Reference books show it. Before the clip. The clip on Chrysler distributor are in a different position though. Further clockwise because vc is used as notch for the Chry cap. Prestolite cap and clip position is different.

Got the whole shift thing, but that would only create a 180 shift on cap position. Unless the motor builder did not time distributor gear right. Ultimately that could lead to lots of issues further down the assembly line. Regardless, once you FOLLOW the manual they should theoretically end up in the same spot. Physics of the parts mandate that. So a 180 out I can see, but shifted one or 2 plug holes means some part in the distributor is different from stock, or the motor timed not to standard.
Aren't you the same guy asking these questions on moparts and dc.com?

Again show me a judge or a car that has been dinged on this....

Number one position if distributor is installed properly is where it is an always before the clip...unless the installer or builder sucks...
 
Aren't you the same guy asking these questions on moparts and dc.com?

Again show me a judge or a car that has been dinged on this....

Number one position if distributor is installed properly is where it is an always before the clip...unless the installer or builder sucks...[/QU

And the distributor drive gear not installed with the slot not parallel to the block centerline.
 
Like dieseldazzle said, rotate the oil pump drive to get your desired positioning. The main reasons for a suggested position was clearance and to accommodate pre-manufactured spark plug wire lengths.
 
Maybe this helps from the old Chitlins ...........

upload_2018-1-26_14-25-43.png



Typical BB ............

DistAlign.jpg
 
MPN74 you keep getting hung up on judging, I am not. I did ask on Moparts, but do not know what DC is. Maybe it mirrors post on Moparts. I am just trying to get some answer, are we just allowed to use one forum? :(I understand the procedure in the book and I do reference it. My point is that if many cars have variations beyond a 180, and I have seen all different locations. Either the engine builder wasn't careful putting motor together or maybe isn't a mopar guy. Chevy distributor timing does not matter.

OR the distributor is not correct internally and that is just as likely from my perspective based on the various Prestolite cam and shaft clockings I have seen.

There really was a correct way it was suppose to leave the factory and I am just asking what it was.

Dave 69 thank you, the Chilton I had not seen. Motor show all like the Chrysler straddling the clip, but based on the note of shift one CW for prestolite that may be correct for my motor. Thanks for that info.
 
MPN74 you keep getting hung up on judging, I am not. I did ask on Moparts, but do not know what DC is. Maybe it mirrors post on Moparts. I am just trying to get some answer, are we just allowed to use one forum? :(I understand the procedure in the book and I do reference it. My point is that if many cars have variations beyond a 180, and I have seen all different locations. Either the engine builder wasn't careful putting motor together or maybe isn't a mopar guy. Chevy distributor timing does not matter.

OR the distributor is not correct internally and that is just as likely from my perspective based on the various Prestolite cam and shaft clockings I have seen.

There really was a correct way it was suppose to leave the factory and I am just asking what it was.

Dave 69 thank you, the Chilton I had not seen. Motor show all like the Chrysler straddling the clip, but based on the note of shift one CW for prestolite that may be correct for my motor. Thanks for that info.

What do you mean by the distributor isnt right internally? And how is this not remedied by rotating the oil pump drive as needed??? Have you gone out and put your hands on it or are you just reading books? Need more info from you to help
 
MPN74 you keep getting hung up on judging, I am not. I did ask on Moparts, but do not know what DC is. Maybe it mirrors post on Moparts. I am just trying to get some answer, are we just allowed to use one forum? :(I understand the procedure in the book and I do reference it. My point is that if many cars have variations beyond a 180, and I have seen all different locations. Either the engine builder wasn't careful putting motor together or maybe isn't a mopar guy. Chevy distributor timing does not matter.

OR the distributor is not correct internally and that is just as likely from my perspective based on the various Prestolite cam and shaft clockings I have seen.

There really was a correct way it was suppose to leave the factory and I am just asking what it was.

Dave 69 thank you, the Chilton I had not seen. Motor show all like the Chrysler straddling the clip, but based on the note of shift one CW for prestolite that may be correct for my motor. Thanks for that info.
It was a question if you were the same individual.....Thats all...Are people not allowed to ask you a question?

Why don't you share a pic of what your problem is? Are you able to provide one?

My Prestolite dual points 440 4spd sits in the correct position in relation to #1 plug....Rebuilt with NOS parts....

So I am unsure of what your referencing to is it your own car.....or are you going off of web pictures, articles, literature etc?
 
I am sorry, but some of your questions come across as hostile and condescending. It is a simple question. IF you follow the MOPAR service manual for setting the distributor gear timing. And you place the Distributor in the motor as directed with the VC pointing towards the center of the motor (You really do not have much room to do otherwise on a hemi because of the intake and fuel lines, where does the rotor point on the cap for #1 wire.

So for those of you that really do not now the variations on Prestolite parts here are 2 pictures. Notice the 2 RB distributor shafts, one is NOS not yet drilled for the collar pin. See how the tip is at a different angle. Because of that the Cam Stop will orient differently if dropped in the same horizontal slot on the distributor gear.

Now look at the Cam stops, all are for Prestolite caps and rotors not Chrysler ones. See the flat at various angles. Again this forces the rotor to point in a different direction. So if someone mixed and matched different parts to salvage a ""hemi" Distributor it could be done but the position of the rotor when #1 is at TDC would be different.

I can also help school you on Chrysler shafts and cam stops, much more universal though. When I work distributors I literally am working a dozen at a time. So I can see and measure differences. For example presotolite IBP-1 bodies have different lengths that drive different length shafts. The mounting face to tip is the same big block length, but the shafts are 3/8" longer which is significant considering the limited engagement depth of the tip. The reason is the bearing to bearing length varied over the years.

I am just trying to learn and equate what I am seeing and doing to what is suppose to be OEM correct. For a bunch of guys that point out a certain bolt under a fender should not be painted to say the distributor doesn't matter seems a little funny. If the nose gasket on a superbird was on upside down does that matter; or would you say it has the gasket so perfect score? If it does matter, shouldn't the distributor and wire orientation? I know that was a little snarky but jeez, it really started as a simple question.

By the way I do read. Service manuals, parts manuals, Master Training documents. A wealth of interesting information to learn from if you did not grow up with these cars from the 70s up.
20180126_222121_resized.jpg
20180126_222134_resized.jpg
 
Top picture third cam down is for a 64/65/68 race hemi with transistorized ignition and NO vacuum advance. I bought one of those in 1971.
 
Thanks Fran, the second one down is stamped B and that is what is in my hemi distributor, but I do not know if that is correct for hemi or if it was a 440 one. Also not sure what early non cap cars had. Should be different since non cap had 10deg initial timing and less mechanical and CAP cars had zero initial and more mechanical adv.
 
I am sorry, but some of your questions come across as hostile and condescending. It is a simple question. IF you follow the MOPAR service manual for setting the distributor gear timing. And you place the Distributor in the motor as directed with the VC pointing towards the center of the motor (You really do not have much room to do otherwise on a hemi because of the intake and fuel lines, where does the rotor point on the cap for #1 wire.

So for those of you that really do not now the variations on Prestolite parts here are 2 pictures. Notice the 2 RB distributor shafts, one is NOS not yet drilled for the collar pin. See how the tip is at a different angle. Because of that the Cam Stop will orient differently if dropped in the same horizontal slot on the distributor gear.

Now look at the Cam stops, all are for Prestolite caps and rotors not Chrysler ones. See the flat at various angles. Again this forces the rotor to point in a different direction. So if someone mixed and matched different parts to salvage a ""hemi" Distributor it could be done but the position of the rotor when #1 is at TDC would be different.

I can also help school you on Chrysler shafts and cam stops, much more universal though. When I work distributors I literally am working a dozen at a time. So I can see and measure differences. For example presotolite IBP-1 bodies have different lengths that drive different length shafts. The mounting face to tip is the same big block length, but the shafts are 3/8" longer which is significant considering the limited engagement depth of the tip. The reason is the bearing to bearing length varied over the years.

I am just trying to learn and equate what I am seeing and doing to what is suppose to be OEM correct. For a bunch of guys that point out a certain bolt under a fender should not be painted to say the distributor doesn't matter seems a little funny. If the nose gasket on a superbird was on upside down does that matter; or would you say it has the gasket so perfect score? If it does matter, shouldn't the distributor and wire orientation? I know that was a little snarky but jeez, it really started as a simple question.

By the way I do read. Service manuals, parts manuals, Master Training documents. A wealth of interesting information to learn from if you did not grow up with these cars from the 70s up. View attachment 564829 View attachment 564830
Hostile...lol What a joke.....Again, they are questions....

Lets see this car your building? Lets see the actual parts restored?

I never stated "it didn't matter" it does when it is built improperly and installed improperly....The majority here including myself do not build their own distributors but Bill Overcash and Frank Badalson have built mine with complete NOS/original parts....

So as you dig deeper have you asked the professionals that build these to OE specs? Like the two individuals I mentioned above....

Or are you going to make another smart aleck remark? I see why your threads on other forums have fizzled.....
 
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