V12 spark plug wires and plugs

[chris_kriner]

Hello everyone...Shes coming along nicely! Cleaned her up the other day for the first time in MANY years. (See new icon pic) lol OK My questions. She runs great, no issues....YET.....While detailing the engine bay. I noticed on closer inspection how old and cracked my wires are. Its just a matter of time before something goes wrong. The spark plugs I couldn't even guess and tell you how old they are. 

 

Question #1:    How hard is it to change the wires on this V12 and run them up into the tubes to the right place. I consider myself a good shade tree mechanic and have done many plug and play wires in my life. But this......lol...well......Should I even attempt his? Any tricks...advice...hey do this, but not that comments? I guess my biggest worry is snaking them up and through the tubes.

 

2nd Question: Recommendations On spark plugs? Which ones will make her run the happiest? Do I need to gap or are there pre gap ones I can just get, like everything else now a days? 

[Paul S Allen]

I bought wires from Chris at Boos Herrel, Jerry Richman also sells ignition parts. I started with the longest wires that have the most bends first. I pulled them with MiG wire smoothed with electrical tape. Some use Vaseline or Silicon lubricant. It’s also a good time to get a new engine harness wire and pull it through.

[Ray500]

If you're going to replace the spark plug wires, best to remove the harness from both sides of the engine and lay it out on a table to either sort out a new set properly trimmed, or to take bulk wire and cut to length which is preferable.  Make sure you know where each of the 12 wires plugs into each side of the distributor.   6 on each side, but if you get them mixed up it won't run!  Draw a diagram of the engine for each plug's position and which wire it connects to on the distributor.  Best to use a continuity tester like an OHM meter to verify each wire in the conduits and tape mark it so when you reinstall it you will know where each end goes.  Pay attention to which holes in the conduit allows which wires to exit to be connected to the spark plugs.  Also once you strip out the old wires from the conduits, good time to repaint the conduits so they look better.  Some of the wires which are 7mm can have a rough exterior making them difficult to crowd inside the covering of the wires.  Yes, some lube can help but do put in the long ones first and short ones last.  Be careful not to nick the cables inside the conduit, they can arc and engine will miss.  Ole Henry I suppose wanted to save money and use the smaller conduits as he never had to replace wires in his!   Good tight connection of the spark plugs and the distributor places are important and seated properly.  Good time also to replace the rotor in the distributor and the plates on each side as they wear down.  I have mine clearing about 1/10,000 of an inch as the distributor rotates firing each plug.  There are places that rebuild those plates and rotors for the best firing in the engine, giving good firing to each plug.   Good Luck!   

[38ShortopConv.]

You have asked about any tricks or advise so here  goes. You just need to be aware sitting in the drivers seat  the left bank cylinders  are the ODD numbers  front to rear 1,3,5,7,9,11. The right bank cylinders are the EVEN numbers front to rear 2,4,6,8,10,12.  The distributor cap terminals are double  numbered and only  read right way up depending which side of distributor they are fitted to,  look at caps and you will figure it out. For example the three front  left bank  spark plugs 1,3,5,  are connected   to  front  left distributor plate terminal numbers1,3,5, Spark plugs 7,9,11, crossover behind generator and  are connected to front right distributor. cap terminal numbers 7,9,11. The right bank is a mirror? image. Just keep track of   the numbers. Remember  to  fit black oval dist. cap lids and rubber boots each side before plugging  wires in and avoid crossovers and jam ups. Connect spark plug terminals last. You did ask for any tricks or advise. Hope this is not too confusing. LZs can be cantankerous.

Edited June 27, 2020 by 38ShortopConv. (see edit history)

[chris_kriner]

Hahhaha Oh my goodness.....I dont know if I am more scared now or not. How about plugs? Anyone find one set/maker works better then the next in these V12's? Can I just walk in and buy or is gaping still a thing with these ol girls like they did back in the day? ....Ray500...YES! On sprucing up and painting the housing. planned on it. I have done this with my oil bath cleaner already

[Cokekid]

I am also going to replace my wiring and while reading some post there are many suggestions on how to do it but nothing is ever mentioned about the wires that also need to go through the conduit. Generator , Coil Resisters.\and Water Temperature

 

Gerry.