MGL RDAC protection and mounting

[nomocom]

I'm planning the install of MGL's engine module (RDAC) on the engine side of the firewall as suggested by the install manual. This allows the engine probes to terminate at the RDAC, then one wire leaves the RDAC and goes through the firewall to the EMS head. The manual suggests that in some installations an enclosure may be advisable for protection from water and oil. I find Lycomings to be a bit like old British engines, I always seem to be chasing oil leaks, so I'm thinking about providing some protection to the RDAC module from what seems like the inevitable oil misting.

On one end of the complexity and weight spectrum a simple Nomex slip cover. At the other end, a aluminum box with a couple 1/16th inch drain holes in the bottom so it can breathe a little. I'd also appreciate a bit of heat/fire protection a cover would offer, though if I'm on fire, I've got bigger problems than losing engine instruments

Thoughts? Experience?

[GrayHawk]

There has been some discussion about RDAC enclosures on the Yahoo Stratomaster users group; but not sure the Yahoo search function works very well.

[Beancounter]

Stan
I believe some have used a hinged plastic box, sort of like a household electrical panel. Perhaps some destructive testing is in order to determine the melting point.
Contact me by PM if you want to know how I mounted the RDAC behind the firewall.
See Chad Jensen's website for firewall forward mounting.

Matt

[rwarre]

I made a metal box to go over the RDAC. Has been satisfactory so far.

[lostpilot28]

Is your only reasononing that you want a smaller hole in your firewall for the single RDAC wire instead of a 1/2 inch hole for a dozen wires? I mounted my RDAC on the sub-panel under the windscreen. The wires passing through a larger hole wasn't really a concern. I wrapped them with high-temp rescue tape and put fire-barrier sealant on both sides of the hole. I only mention this because my engine compartment gets really oily...seems a light coat is on everything.

[Rainier Lamers]

We have seen anything from tupperware boxes to custom made enclosures costing many times the cost of an RDAC unit.

The units are not sealed and the terminals where you connect the wires are exposed. While we have had very good experiences with the terminals (these are German WAGO connectors of excellent quality and corrosion resistance), I can recall a single case of ingress of engine coolant caused by a leaking bottle mounted right above the RDAC (which, ahem, was ah, stupid ?).
Other than that we have never had a unit returned for repair that had anything to do with ingress of any liquid whatsoever.

Nevertheless, there's lots of wires so some form of protection is certainly not a bad idea. I don't however think there is much reason to go overboard with this unless your aircraft is going to be used in very unusual conditions.

Rainier
CEO MGL Avionics

Originally Posted by nomocom

I'm planning the install of MGL's engine module (RDAC) on the engine side of the firewall as suggested by the install manual. This allows the engine probes to terminate at the RDAC, then one wire leaves the RDAC and goes through the firewall to the EMS head. The manual suggests that in some installations an enclosure may be advisable for protection from water and oil. I find Lycomings to be a bit like old British engines, I always seem to be chasing oil leaks, so I'm thinking about providing some protection to the RDAC module from what seems like the inevitable oil misting.

On one end of the complexity and weight spectrum a simple Nomex slip cover. At the other end, a aluminum box with a couple 1/16th inch drain holes in the bottom so it can breathe a little. I'd also appreciate a bit of heat/fire protection a cover would offer, though if I'm on fire, I've got bigger problems than losing engine instruments

Thoughts? Experience?

[nomocom]

Originally Posted by lostpilot28

Is your only reasoning that you want a smaller hole in your firewall for the single RDAC wire instead of a 1/2 inch hole for a dozen wires?

On my old 3, there is not easy access to the cabin side of the firewall, the forward deck is riveted in place, so work in this area is slow and uncomfortable. So, the 20+ wire terminations on the engine side is a big reason the RDAC is so attractive. I'll bring some wires forward, fuel sensor for example, that most the time stay behind the firewall, so I don't know that it will do much to reduce firewall penetrations.


Thanks everyone for all the helpful comments.

[Brian Vickers]

Don't have all the answers... but this might work for you. I purchased an aluminum box from an electronics web store; 3? x 7? x 5.? I think it was about $8.00, plus shipping. Added some angle and nut plates to relocate the four screws that hold it closed. It's mounted inside the right cowl cheek, and is easy to open and service the RDAC. No scuffing knuckles reaching behind the engine in this location. Check out the space in the cowl cheeks.

[humptybump]

I recently finished installing the MGL RDAC on the firewall. I received more than one "suggestion" to protect it from moisture. I concluded the most likely moisture would be from the front and above so I went with a 3/4 cover.

click for more details

[sblack]

Do you guys just bolt the rdac right to the firewall or do you provide some vibration isolation?