Not many people have chimed in. I'm also interested in what people have done. I've been stalling drilling mine, but I'm about finished with the avionics and will be riveting my panel substructure in soon and would rather install the passthrough prior.
I'm thinking I will use the existing LH hole for my battery cable, install a 1" firesleeve passthrough near the center, and use the RH passthrough hole only if I were to run out of room in the 1" hole.
I can't see your image but if that is the roughly thumb-sized holes left and right on the firewall, that is indeed what they are intended for. However, I am using sealed CPCs for my passthrough and the extended sleeve (about 3 inches) would have interfered with the motor mount, so I covered the existing holes with riveted stainless steel covers and relocated my openings. My point is that you can relocate things as needed and appropriate for your installations.
I'm using the SS fire-sleeve pass throughs from ACS you've mentioned. I ended up with one of each size. The interior firesleeve eats up a lot of space. The #2 battery I bring through the existing hole which I enlarged for a bulkhead fitting. The smallest SS pass-through I've got on the top-left of the firewall and will be using for ignition related wires. The 3/4" pass-through I've got in the little slot designed for the heat boxes and alternate air door. The 1" pass-through I've got on the upper left for all the thermo-couple wires and various other engine monitor wires. Van's has you drill another hole for a bulkhead fitting if you position the manifold pressure sensor on the inside. The existing hole on the far right I probably could have used for the 1" SS pass-through but didn't, thinking I would use it for something else. I'm going to plug that one.
Also, if you happened to drill the holes in the stainless recess according to the plans (as I did), you'll find that most of the nice pass-throughs for prop/mixture/throttle cables won't fit because the holes are too close together. I found these on ACS which do fit. I installed them just the other day.
https://www.aircraftspruce.com/catalog/appages/6000metalgrommets.php
fyi: If you look at the Van's wiring harness plans, they actually drill a different hole next to the skin to run the battery cable through.
I like the idea if CPCs but can you use them with the thermocouple wire for EGT and CHT?
This is on an RV-7 - but for what its worth I used 4 for electrical. Top "corners" carry EGT/CHT and other engine sensor wires; one near the center top carries Electronic Ignition leads/ mag P-lead; large angled one on the right side carries all power wires.
I also used 3 additional passthroughs like these for the throttle, mixture and prop cables.
Your photos are not coming thru. Just shows a dash.
I like those SPHERICAL FIREWALL FITTINGs, what size did you order for the three control cables?
However, I am using sealed CPCs for my passthrough
Sorry, can you educate me on what a sealed "CPC" is? I am probably 1 year + from working on firewall but trying to learn.
Thx
Steve
I like those SPHERICAL FIREWALL FITTINGs, what size did you order for the three control cables?
fyi: If you look at the Van's wiring harness plans, they actually drill a different hole next to the skin to run the battery cable through.
Putting together a BOM for my Firewall and Tunnel.
McMaster Carr has it...
While you're at it, you may want to purchase one or two of those Airward tunnel access covers.
About to start on the Firewall and Tunnel with the materials I received today. Before I start punching holes in the firewall I wanted to check if I'm leaving anything off.
Unless you're going to use the little slit for the alt-air and heat-box cables you might want another pass-through. I enlarged the little slit and put a 3/4" SS passthrough in that location for that purpose.
Is that to the right of the manifold area?
.... so I used a marine insulated firewall pass-through terminal.
I assumed the battery/power line came through the 1" Pass through on the right. And the left one was for all other wires...
Good deal, I actually made some solid progress on everything last night. Going to order another 3/4 inch pass-though for alt air/ and heater cables. Also need to order some Stainless Steel pull rivets to attach these passthroughs. Tried to use screws but the backside is really close to some brackets so pull rivets will work best.
Yep. I used CCP-32 rivets.
Oh I ordered CCPQ-43 because I match drilled to 1/8th.