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-   -   Distributor/Spark Plug Setup (https://67-72chevytrucks.com/vboard/showthread.php?t=856200)

ahoke 12-25-2024 09:08 PM

Distributor/Spark Plug Setup
 
1 Attachment(s)
Went to replace the plugs/wires on my '72 with a 350. Curious if this looks correct (picture taken before removing the old wires). Seems like from my I can find online wire 1 is in spot 8? If so what effect does this have on the engine/performance? Obviously going to correct it but just curious.

pjmoreland 12-25-2024 09:46 PM

Re: Distributor/Spark Plug Setup
 
It looks like the distributor was just installed with the rotor clocked a little more clockwise than normal. It is irrelevant from a functionality standpoint. It would be a hassle to adjust it at this point if all you're wanting to do is replace your plug wires. You would have to set the crank at TDC, pull the distributor out of the block, rotate the oil pump shaft a little with a long screwdriver and then go through the trial and error process of reinstalling the distributor repeatedly until you get the rotor pointing in the direction you want #1 to be. You'd need to readjust the timing with a timing light afterward. Probably not worth the effort.

ahoke 12-25-2024 10:17 PM

Re: Distributor/Spark Plug Setup
 
Appreciate the response. Basically, just reinstall the new wires to match what they looked like before then?

pjmoreland 12-25-2024 10:21 PM

Re: Distributor/Spark Plug Setup
 
Yes, assuming the current wires are installed in the correct 1-8-4-3-6-5-7-2 order.

1970 CST Short Wide 12-25-2024 10:23 PM

Re: Distributor/Spark Plug Setup
 
Best way is One at a time so you don’t get mixed up.

Rust_never_sleeps 12-25-2024 10:27 PM

Re: Distributor/Spark Plug Setup
 
There is a conventional way that most folks clock their distributor, but no reason it has to be done that way.
I found this out the first time I swapped plug wires

1970cstblazer 12-26-2024 09:06 AM

Re: Distributor/Spark Plug Setup
 
To prevent cross firing, try not to have the wires touch each other.

Myself 12-26-2024 11:47 AM

Re: Distributor/Spark Plug Setup
 
Quote:

Originally Posted by 1970cstblazer (Post 9360075)
To prevent cross firing, try not to have the wires touch each other.

I think that's an old wives tale going back to old fashioned plug wires. I can't see any way for the newer thick silicone jacketed wires to cross fire each other. There's a much higher chance of carbon tracking inside the cap causing a misfire than wires touching or laying on each other.

RichardJ 12-26-2024 02:26 PM

Re: Distributor/Spark Plug Setup
 
1 Attachment(s)
Rules of physics may not agree. Current in one wire will generate a magnetic field and cause current to flow in a parallel wire.

Steeveedee 12-28-2024 02:36 PM

Re: Distributor/Spark Plug Setup
 
^ While this is true, the wires would have to be parallel for awhile for enough counter EMF to make a crossfire, and the magnetic field tapers off exponentially. Most wires these days have a wire winding around the conductor, ADDED- or has the coil right on the spark plug, /ADDED which minimizes those fields. The wires on my truck are like that. It was an issue back in the day, though, for sure.

Stanco 12-28-2024 07:30 PM

Re: Distributor/Spark Plug Setup
 
Your distributor is installed correctly with #1 in between the vacuum advance can and the points adjustment window.

Now some folks will tell you that the #1 terminal should be pointing at the #1 cylinder. While this is correct for the HEI distributor this is not the way GM installed the earlier window points distributors.

Check out the assembly manual.

https://www.567chevyclub.com/images/C10/Distributor.jpg

https://www.567chevyclub.com/images/...clocking-1.jpg

https://www.567chevyclub.com/images/...r-clocking.jpg

Steeveedee 12-28-2024 07:42 PM

Re: Distributor/Spark Plug Setup
 
I'm liking View E- "Clips on line perpendicular to axis of engine", though they did misspell perpendicular on the drawing. Perpendicular makes sense, for best access to the clips.

Accelo 12-29-2024 03:55 PM

Re: Distributor/Spark Plug Setup
 
It actually does make a difference if the distributor is correctly clocked and wired.
It has to do with the clocking between the end of the rotor and the tabs on the inside of the cap. It works either way. The gap the spark has to jump from the rotor to the cap can be larger than optimum.

The distributor gear has 13 teeth, so each tooth change moves the whole distributor about 28 degrees. Each cap terminal is 45 deg apart.

71CHEVYSHORTBED402 01-02-2025 02:06 PM

Re: Distributor/Spark Plug Setup
 
Regarding SPW contact

Quote:

Originally Posted by Myself (Post 9360104)
I think that's an old wives tale going back to old fashioned plug wires. I can't see any way for the newer thick silicone jacketed wires to cross fire each other. There's a much higher chance of carbon tracking inside the cap causing a misfire than wires touching or laying on each other.

Might be a wise tale, but no-contact is a good place to be for an engine bay right. As a rule I avoid contact between parts unless contact is required by the assembly.

I didn't know that Stanco, for a points distributor - thanks for sharing; and nice engine bay.


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