Is my 351C Distributor 180 out?

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andy72

Well-known member
Joined
Jul 3, 2014
Messages
245
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Location
california, ca
My Car
1972 mach 1 351 ram air
[url=https://ibb.co/R9rNbJs][img]https://i.ibb.co/376vdPj/DSC06636.jpg[/img][/url]
The 72 Mach I am restoring came with a Mallory Unilite distributor installed.

The car seemed to run fine.  Started right up.   Then I tore it apart to restore/clean up.

I took lots of pictures. 

The picture shows the spark plug wires on the car as I got it 3 years ago. (it doesn't look like that anymore!)

You can clearly see that the #1 wire goes to the front passenger side of the distributor.

Now that I'm reassembling, I googled the firing order and got the 2nd picture.

In this picture, the #1 position on the distributor is rear driver side.

It seems like the distributor is 180 degree different between the two.

The "concours" set of spark plug wires I got from NPD, which have the cylinder numbers printed on them, don't fit correct at all.

Any ideas what's going on here?

DSC05728.JPG

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That’s just a picture of the firing order. It can be set in another position as long as the firing order is the same and the rotor is pointing at #1 plug at T.D.C. Maybe you should get a shop manual to help you out. There are all kinds great information in them.

 
Did you remove the distributor? The distributor, as shown in your diagram, is located with #1 at the left rear (left as viewed from the driver seat) so the vacuum advance fits. The distributor cap typically has a "1" next the the #1 terminal tower.

 
Yes, I had the distributor out.  I documented that the rotor was pointing exactly straight back pointing at the firewall.

The motor was never turned over while it was out.  I reinserted the distributor in exactly the same position.

The cap has no #1 indication on it.  The vacuum advance portion obviously needs to be facing forward.

This is of course does not affect where the rotor is positioned inside.

The wires like I said are numbered, but the lengths don't fit correctly.

For instance, in the diagram #8 wire is short because it is on same side of motor.

On my car, #8 has to stretch around to the #2 position on the diagram because my distributor thinks it is 180 out of physical position.

This is where I am confused.

We used to time a small block I believe by putting #1 cylinder up on its compression stroke and then point the rotor at it?

I may need to talk to Mallory tech support?

 
The plug wires usually come numbered and cut to fit on the dist. cap as Ford had them.

Either pull the number one plug, Right Front cylinder, or take valve cover off so you can see the valve position. Bring the engine over until the # 1 is on the compression stroke. Use the timing pointer on the harmonic balancer to stop right at 0, zero, TDC. Then pull the distributor out and point the vacuum advance to the correct position and rotate the rotary button so that it falls pointing to the #1 position on the cap. A Ford cap has #1 molded into it Mallory might not. You might have to pull distributor in and out a couple times because as you go in the gear makes the rotor turn. Has to be pointing right when distributor is all the way down.

Hope you have the clip on the oil pump drive shaft so it does not fall into the pan.

If you have long enough wires the distributor can be in any position as long as the wires are indexed correctly.

I went with a friend once to go look at a 65 Mustang coupe 289 3 speed had console and lots of great parts. The young boy said he had it for couple years and could not get it to run and his mom told him it had to go. We put a battery in and turned it over and it was kicking back and backfiring. I told my friend that he had the wires in the wrong position and he paid him the $125 he wanted for the car and bought it. This was in the 70's. I pulled the #1 plug rotated to compression and stopped on TDC. Popped the dist cap and rotor was way off. He even had the wrong firing order I think he had like chevy. I put in right order and the engine fired right up and he drove the car home. The boy was so pissed off, lol.

 
The wires definitely appear to be cut to match the position of #1 in the diagram I posted.

I was hoping someone with a 351C could verify that their #1 position on their distributor cap is pretty much like the diagram.?

That would explain that whoever installed the Mallory Unilte distributor on my motor did it kind of random.

In other words, they didn't care where the physical #1 ended up at.

I think from reading the Mallory install instruction online, that my issue is correctable.  



 
The "concours" set of spark plug wires I got from NPD, which have the cylinder numbers printed on them, don't fit correct at all.

Any ideas what's going on here?
 In the diagram, I have the #1 where #7 is and I had a set of NPD concours wires the fitted as they should.

 In other words the #1 wire and rotor point somewhat toward the #1 spark plug. This will visually change slightly depending on where the timing is set when the distributor body is rotated as needed. Hope that make sense.

Geoff.



 
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Yes, it sounds like the rotor is rotated 180°. I would pull the distributor back out and turn the rotor so it faces straight front and pull the wires off the cap and reinstall them in the order they are in the diagram. I would also verify the rotor is pointing at #1 on the compression stroke.

 
Yes, it sounds like the rotor is rotated 180°. I would pull the distributor back out and turn the rotor so it faces straight front  and pull the wires off the cap and reinstall them in the order they are in the diagram. I would also verify the rotor is pointing at #1 on the compression stroke.
 Don, it maybe that the distributor gear is 'off' by 1 or 2 teeth when it meshes with the cam.

 
All of the spark plug cables are on the opposite terminals, so someone stabbed it with the rotor 180° out, and their fix was to swap the cables around, rather than take a few minutes to pull the distributor and point the rotor in the right direction. It ran fine, just everything was bass ackwards.

 
All of the spark plug cables are on the opposite terminals, so someone stabbed it with the rotor 180° out, and their fix was to swap the cables around, rather than take a few minutes to pull the distributor and point the rotor in the right direction. It ran fine, just everything was bass ackwards.
 Ah, I see what you mean.

 
The Mallory distributor wiring was indeed random. It appears the current distributor is an OEM style distributor. Therefore the position of the rotor for the mallory isn't useful for installing an OEM style distributor and have the plug wires where Ford put them. I would start over by bringing cylinder number one to TDC on the compression stroke. The number one wire is supposed to be the 4th position (CCW as viewed from the front ) from the cap retainer clip on the front side of the distributor (per 71-72 electrical assembly manual, E2Z-130-2 dated 5/19/72). Re-stab the distributor to have the rotor line up with the correct cap position of cylinder number one. It may take several attempts as it is very easy to install it one tooth off. You may need to securely tape a socket to a long extension (1/4" drive) and slightly reposition the oil pump drive rod to get the distributor to go all the way in. Keep us updated, good luck. Chuck

 
All of the spark plug cables are on the opposite terminals, so someone stabbed it with the rotor 180° out, and their fix was to swap the cables around, rather than take a few minutes to pull the distributor and point the rotor in the right direction. It ran fine, just everything was bass ackwards.
Exactly, #1 wire in Andy's pic is where the #6 should be on the cap, indicating the rotor is 180* out. While the engine could care less what terminal #1 is at, factory fit wire sets are always going to be designed to fit with the #1 in the factory location on the cap. 

Turn the engine over 'til it's at 10* BTDC on #1 compression stroke, pull the distributor, mark the base where #1 terminal should be, and reset it to the factory location. Saves a lot of head scratching later on.

 
Thanks everyone for helping me confirm what I feared.  The distributor needs to come out. 

Here is a current pic of my project.  I have received tons of great help and advice from all the members the last couple years.

I hate to go backwards a bit, but it must be done.

(The interior was done first.  It's close to being a driver.)

It's been 20 years since I've done this but I better redo the timing . I just watched a Jegs produced video on You tube. Pull the plugs, bring the #1 up on its compression stroke.  Timing mark at TDC.  Point the rotor at the position on the cap that you want to be the #1.

The picture shows the plug wires in the incorrect positions on the cap. You can see the lengths are all funky when #1 isn't in the correct position physically.   I replugged them to match the diagram, and lo and behold, the wires fit correctly now.

It's gonna be a while until I can start it up but I'm kinda glad I found this now.

Thanks again

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If the engine hasn’t moved, put the distributor in with the rotor pointing a bit past the firewall. If it was pointing directly aft, aim the rotor over towards the passenger corner. It won’t seat. Apply pressure while cranking it over. The distributor will pop in. Then confirm it is correct by finding TDC on number one and rotor pointing to number 1.

 
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