Firewall Feed-through for Thermocouple Leads

[Rob58]

It would be my preference to use a firewall connector for all wires from the engine compartment, but that doesn't seem like a good idea for the EGT/CHT leads going to the engine monitor. I'm familiar with the firewall penetration parts from Aircraft Spruce. However I am wondering what clever options might exist for making a very neat and weather-proof feed-through?

 

[weirdjim]

It would be my preference to use a firewall connector for all wires from the engine compartment, but that doesn't seem like a good idea for the EGT/CHT leads going to the engine monitor. I'm familiar with the firewall penetration parts from Aircraft Spruce. However I am wondering what clever options might exist for making a very neat and weather-proof feed-through?

A machine screw, lockwasher, and nut; a FIBER shoulder washer, and a FIBER flatwasher. Two bits worth of parts. Fireproof for the time of an engine fire. If the fiber burns through you've got more problems than a burned hole in the firewall. Crimp terminals on both the engine side and the cabin side. With millivolts and microamps a #4 screw is overkill; you can use #2 if you've got them.

Jim

 

[Dr. O]

https://www.casa.gov.au/sites/g/files/net351/f/_assets/main/rules/1998casr/021/021c99s2c16.pdf

Notice especially Paragraph 7.

Jim's way will work with a bit of dissimilar metal voltage being generated.