Plug Wire "Rebuild?"

[jordankjcm]

I have several old 24v military plug wires that have the rubber casing removed. It appears that is the only issue with them. I was thinking that maybe I could remove the straight end, and slide a new neoprene tube over the the braiding. It appears that the metal ends are soldered to the metal braiding, but I can't figure out how the rubber ends and springs are attached. Does anyone have experience with this doing this sort of thing?

[HingsingM37]

I have never attempted to disect one of the waterproof wires. It sounds as if it will be more time and trouble than its worth. It does not look as if they are meant to come apart, they are bascially the same in construction as an aircraft engine plug wire, not meant to be serviced.
Perhaps install regular automotive wires until you can come up with a new set of waterproof ones .

[k8icu]

David is correct the plug wires get thier design from the aircraft industry. They are not servicable that I know of.

[cuz]

The aircraft modern shielded wire assemblies are quite serviceable. That is if you stay with the top shelf brands like the Slick and TCM harnesses. The older classics like the radials are even simpler to service and they are much closer in design to the tank and tactical vehicle ignition harnesses.

The real difficulty is with obtaining replacement parts. The aviation parts are plentiful and a wee bit more expensive than the automotive stuff but the older classic aircraft parts are generally larger thread sizes with the harness shield nuts since the aircraft use 18mm plugs for the most part and we are dealing with 14mm plugs. But a certian degree of mix and match can be done.

Jordan,

If you have a airport nearby stop there at an FBO (Fixed Base Operator) shop and talk with their lead mechanic or maintenance director.

The first two engines are 1940's engines and have very similar plug lead construction.

W670

TCM W670.JPG (220.53 KiB) Viewed 825 times

This is a 7 cylinder, 670 CI, 220 HP engine Produced during WWII. I installed this engine in 2000.

R1340AN1

PW1340.JPG (159.19 KiB) Viewed 825 times

This is a 9 cylinder, 1340 CI, 600 HP engine produced during WWII. I installed this engine this past spring.

The engine below uses the modern shielded spark plug lead still produced today for piston engine aircraft. This is lighter, more compact and easier to assemble.

TCM O-470-11.JPG (251.3 KiB) Viewed 825 times

This is a 6 cylinder, 470 CI, 215 HP engine produced in 1951. I just re-installed this engine two weeks ago.

[HingsingM37]

Wes,
Good info. Our old-timer A&P at the hanger had always said to replace plugs and wires and never attempt to clean or repair,. That always stuck in my head. I stand corrected

[cuz]

I too am an old timer A&P / IA now I guess. We use the plugs for 500 hours (cleaning and gapping them every 100 hours) then replace with new at 500 hours. On the old simple engines just like these old simple truck flat heads one of the easiest routine maintenance tasks you can do that gives you the most bang for your time is to clean and regap plugs and check points/timing periodically. If you have access to a decent plug cleaner/tester you can use the plug's condition on the tester to decide when to go with new plugs or just use the operating time to determine when you want to change them.

Money really is a big point here since the aviation plugs are now selling at $22 to $28 each for the massive electrode type and $55 to $80 each for the fine wire types. So most owners don't just throw their plugs away at 100 hour inspections. They clean and gap them . It runs between $400 and $900 bucks for those engines in plugs at changing time!

Even these 2243 and 2245 plugs are hitting $12 to $15 depending on where you buy.