Spark Plug Wire Routing

[sglynn]

Are there some "rules" about routing the spark plug wires? I've been playing around with them for days to figure out where they should route and what they should be fastened to and have questions.

1. Can I secure plug wire with adel clamp to the oil hose?
2. Can wires be secured to engine mount or should I secure them to only the engine?
3. Can plug wires just be wrapped together into a stiff bundle with other wires and not fastened to anything?
4. How far can the plug wires run without being fastened to anything?
5. Is it best to route them above the oil filter or below? I can see better above, but they are barely long enough if above.
6. If I route below the oil filter what can I fasten them to? Fuel line?

Any photos or tips on routing the plug wires would be appreciated.

[flion]

I can't answer all your questions definitively but some of them I can. My setup uses high-tension leads to automotive plugs for the LSE ignitions. However:
1 & 6. Never mix electrical and hydraulic/pneumatic (fuel/oil/etc) routing.
2. They can but be sure to allow for engine movement. The coils for my 'right' LSE (actually the bottom plugs) are attached to the engine mount as there is no good spot on the engine to mount them. 10 years and no problem with those wires.
3. No. Plug wires should not be routed with any other wires. Maintain at least 1/2" separation. Plug wires can be bundled together and, at least for the high-tension wires, hot rod suppliers sell 'combs' to organize your plug wires.
4. Pretty far. For instance, my right-hand lower plugs run free from the engine mount. Here is the Kitlog entry with a photo. Using the LSE gave me the luxury of making my own custom leads, so I could use straight connectors for the lower plugs and 90-degree connectors elsewhere plus custom length, which segues into your
5. As long as it isn't vibrating and rubbing on anything, either should be Ok, though you will probably be happier if the wires are not stretched to make your routing. Easier visual is not that important; if the routing is secure you are mainly interested in the connections.

Like I said, my setup is slightly different than standard aircraft wires but other than the flexibility I had for planning it mostly holds true.

[pilot2512]

http://www.vansaircraft.com/public/rv14Cockpit.htm

Here is the link to van's 360 walkaround of the RV-14. Sometimes good to see how Vans does things. Takes a few minutes to load but you can use your mouse to move all around and see from different angles.

Jay

[BillL]

Originally Posted by sglynn

Are there some "rules" about routing the spark plug wires? I've been playing around with them for days to figure out where they should route and what they should be fastened to and have questions.

1. Can I secure plug wire with adel clamp to the oil hose? I wouldn't do that. The oil hoses grow in diameter with varying pressure so, not a good idea.
2. Can wires be secured to engine mount or should I secure them to only the engine? If they are only to the engine they all move together. If on a mount then just provide more slack between joints.
3. Can plug wires just be wrapped together into a stiff bundle with other wires and not fastened to anything? Sure if 6 gs won't push them into something.
4. How far can the plug wires run without being fastened to anything? Far as comfortable they won't be able to rub something.
5. Is it best to route them above the oil filter or below? I can see better above, but they are barely long enough if above. I ran all mine above the filter just to keep oil from dripping on them. Plenty long for my engine.
6. If I route below the oil filter what can I fasten them to? Fuel line? Make new attachment points, I made several from 5/8 wide, .063" thick 4130 strip from Spruce.

Here were my rules:

Don't let them rub anything.
No touching hard things
Only attach to engine.
Keep them tight to engine so all moves together.
Minimal length over heads to keep wind from causing deflection and rubs.

The routing had to be a bit creative with the lengths the factory provided.

PM sent for email address. Way too many photos to post.