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MGL RDAC protection and mounting

nomocom

Well Known Member
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 :eek:

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

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
 
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.
 
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


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 :eek:

Thoughts? Experience?
 
engine side enclosure

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.
 
Mine is in the cowl cheek

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.

 
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.

 
Do you guys just bolt the rdac right to the firewall or do you provide some vibration isolation?
 
Both of mine are screwed to their enclosures on standoffs. The enclosure is attached to the firewall.
 
Heat soaked MGL RDAC

I've been flying with the MGL Xtreme RFIS EFIS / EMS for three years now. I've concluded that my installation - which is mounted high on the right on the hot side of the firewall is not ideal.

On long flights I start to see random and widely fluctuation fuel flow readings. I've debugged it several times with Matt. I've replaced different parts. I've concluded it is getting heat soaked.

Even through MGL offers the firewall as a mounting suggestion, it also states the operating temp for the RDAC as +70C (158F) and the hot side of the firewall sees air temps above this limit.
 
metal box

I fabricated an aluminum enclosure that screws on to the firewall. It is located high in the middle of the firewall(engine side). No problems for 850 hours.
 
My 6A has a battery location the same as the 7A. I mounted my rdac on the face of the battery box.... I have a temp probe on it 130deg. All wires run on existing eng mount tubing.

When I do my RV3, I will mount it in the cheek. It sure is a very easy way to wire the engine monitor.
 
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