I am finally done painting the thing, so I can move to new challenges.

I am working on the firewall now and would like to get all holes just about right the first time.

I am installing a JPI EDM930 engine monitor (very similar to VM1000C), and need to route fifty-some tiny wires through the firewall. I bought a couple of 16 pin Amphenol connectors a an early stage, but this is clearly not enough. I also have some concerns about cutting and soldering all those wires, as this surely introduces yet fifty-some new possible sources of failure. Most of the wires are also shielded and what have we all.......

I lean towards making one large harness that simply runs thrugh the firewall in one or two bundles and just live with the trouble if I ever need to take of the engine.

What did you guys do and how did you make it look awardwinning nice and yet fireproof???

Photos GREATLY appreciated!

Tim,

I wired my instrumentation just as you propose. I have an Electronics International MVP-50 monitoring system in my IV-P, and the wires are made of material that does not solder easily (at all??). I ran most of them (specifically the thermocouple sensor wires) through a rubber-sealed grommet as a bundle and terminated them at the MVP-50 computer. The engine ends of these wires came with spade terminals crimped on from EI, and these attached to the thermocouples themselves with spade terminals on short leads. The most serious issue this creates is that each spade connection must be disconnected and the wire bundle separated from the engine to remove it. LOTS of hassle, but this minimizes the connections…and trouble. I’ve run it for almost two years and just short of 500 flight hours now, and the only problem has been the failure of one EGT sensor. This was easily replaced and re-secured within the wire bundle.

Bob P