Firewall Layout

[pfhoeycfi]

I mounted my RDAC and main fuse panel on that upper portion and it works just fine, here's a picture of a mockup of my firewall with the engine removed.



The only real concern is that you have enough space between the fuel tank and upper firewall for your nutplates/screws, and I found I had plenty of clearance for this.

Did you have any issues with your RDAC location when you installed the turbo & turbo cooling. I'd like to rivet a couple of rails (sq tube) in that location now in order to mount the RDAC at a later date...so that I can put the glareshield and tank in now. Engine etc is on order but I want to keep moving.

peter

[Rynoth]

Did you have any issues with your RDAC location when you installed the turbo & turbo cooling. I'd like to rivet a couple of rails (sq tube) in that location now in order to mount the RDAC at a later date...so that I can put the glareshield and tank in now. Engine etc is on order but I want to keep moving.

peter

My turbo cooling pump/cooler ended up on the bottom of firewall. RDAC or no RDAC, I simply couldn't find a way to mount the cooling components high on the firewall like the -B models can.

[Spaceman]

I mounted my RDAC and main fuse panel on that upper portion and it works just fine, here's a picture of a mockup of my firewall with the engine removed.



The only real concern is that you have enough space between the fuel tank and upper firewall for your nutplates/screws, and I found I had plenty of clearance for this.

Did you have any issues with your RDAC location when you installed the turbo & turbo cooling. I'd like to rivet a couple of rails (sq tube) in that location now in order to mount the RDAC at a later date...so that I can put the glareshield and tank in now. Engine etc is on order but I want to keep moving.

peter

You should have room on your B-model. I recently did all this and the only thing I attached to the upper firewall was the little turbo radiator. Everything else fit below where the tank was not in the way!

[pfhoeycfi]

I've mounted the coils, solenoid, reg, filter, alt elay etc to the firewall with standard an bolts and nuts just like I've seen in pics of other installations. Now i'm asking myself how will I pull any of these items if I have to. It wasn't too bad getting them on the fw w no windscreen, glareshield and tank installed. Once the windscreen etc is in I'm guessing to pull any of those firewall items will require one person upside down in the cockpit to hold back on the bolts while another removes the nuts upfront. Should I have used nutplates on the firewall for all of these items or am I overthinking this?

Also....I installed 2 fuseblocks on the cockpit side of the firewall and thinking that's a tough reach to replace fuses. Where are builders installing their fuseblocks?

Peter

[Rynoth]

Hi Peter, I went halfway with nutplates. Anywhere bolts would have been particularly hard/impossible to reach with the fuel tank/windshield installed I used nutplates. For the ones that have direct access later (even if needing a second person or a taped-on wrench), I just used nuts. As for fuseblock in the cockpit, I was ok with needing to go upside-down to replace a fuse, didn't deem it necessary to access them in-flight, so they're on the firewall.

[Bryan Cotton]

Everything on my firewall is installed with a nutplate.

[sonex1374]

Peter,

Definitely install nutplates for any accessory fastened to the firewall that you can't easily get a wrench on the nut inside. This is especially hard for things mounted around the fuel tank (or anywhere above the halfway point of the firewall). The good news is that you can add nutplates to fit your mounting hardware at any point even after you've been flying, so the next time you have something off the firewall go ahead and add those nutplates. You might have to use a long piece of safety wire thru the firewall holes to help position the nutplate, but it's very do-able.

Jeff

[pfhoeycfi]

As of now I have the bolt heads on the cockpit side, nuts on the engine side. No accessory hardware is above the height of the rudder pedal torque tubes. That said its probably a good idea to get nutplates in.

Thanks everybody

Peter

[NWade]

Hi Peter,

I would recommend against having bolts on the cockpit side of the firewall and nuts on the engine side. First, the engine side of the firewall is going to be exposed to more heat, moisture, and vibration. These are all bad things for nylon self-locking nuts. Also, if the nut starts to loosen you won’t see it as readily if it’s on the engine side of things, as gravity will keep the bolt from backing out while the nut continues to loosen. Additionally, many of the fastener locations will become difficult to access after the fuel tank and panel are in. While there may be space to slide a nut up between the tank and the firewall, you are *not* going to be able to pull a bolt out on the cockpit side without removing the fuel tank - which is quite a big job!
My advice: put in nutplates. They’re not that hard to do and they will make all future engine work and maintenance easier.

As for the fuse blocks: I put mine behind the panel, attached to the underside of the glareshield on the left side of the cockpit. This keeps them out of the way of instruments, but makes it possible for me to reach up under the glareshield and replace a fuse without having to crawl down to the firewall or have wires running extra places (like fuselage side-panels). After all, extra wire runs mean more electrical resistance, more weight, and more chance of being a snag/kick hazard!
Here is a photo of the underside of the glareshield, looking up from about the pilot’s left knee. The photo is mirrored, sorry. You can see the fuel tank at the top of the pic, the instrument panel crosstie at the bottom of the pic, and the pilot’s NACA vent in the upper right.

Hope this helps!

—Noel
Sonex #1339