Firewall cable shields

[RickWoodall]

Goofy question, but hope someone can give me the info.
I have the following cables to run through the firewall and ACS has a bunch of various sizes of stainless shields. What is the best size to use?

For mix, throttle, oil cooler door and cabin heat cables, can someone tell me what they used size wise for the stainless shields? There are different size holes and allowance for dif size grommets, I am sure i can adjust to fit, but if someone figured out the best size, PLEASE LET ME KNOW. Want to get them here and on prior to holidays and get this engine HUNG.

Thanks.

[Mike S]

I ordered a bunch of the 1/4 hole, two piece units from Vans.

http://www.vansaircraft.com/cgi-bin/...rewall-shields

I find it easy to drill the center hole out as needed, just use a couple of screws and nuts to hold the two pieces together as you drill.

I use a Unibit with slow rpm, high pressure.

Good luck

[flion]

I used the eyeball assemblies for mechanical pass-through (http://www.aircraftspruce.com/catalo.../eyeballfw.php) and regular grommets and shields for wiring. The eyeballs keep the cable firmly oriented at the firewall and also grip so it doesn't work in and out. The ACS page includes recommendations for which to order for which applications.

[ronschreck]

Originally Posted by flion

I used the eyeball assemblies for mechanical pass-through (http://www.aircraftspruce.com/catalo.../eyeballfw.php) and regular grommets and shields for wiring. The eyeballs keep the cable firmly oriented at the firewall and also grip so it doesn't work in and out. The ACS page includes recommendations for which to order for which applications.

If you go this route, I don't recommend the blue anodized (Model TTP)eyeballs. They look nice and are easy to install, but when it comes time to replace cables I found that the fine threads were galled and I destroyed the eyeball to get them apart. Also, you need to access the back of the firewall to remove these. I replaced them all with the 6-screw type (SE961-B). These are easily disassembled from the front of the firewall.

[DanH]

Originally Posted by ronschreck

If you go this route, I don't recommend the blue anodized (Model TTP)eyeballs. They look nice and are easy to install, but when it comes time to replace cables I found that the fine threads were galled and I destroyed the eyeball to get them apart. Also, you need to access the back of the firewall to remove these. I replaced them all with the 6-screw type (SE961-B). These are easily disassembled from the front of the firewall.

B-series are aluminum. Firewall pass-throughs should be steel (S-series).

[flion]

Yeah, sorry, I just assumed it would be obvious to use steel on a stainless firewall. Also, I 'lubed' my eyeballs with high-temp RTV when I installed the cables just to make sure they sealed better. I had occasion to remove one of them and it was no problem to peel the cured RTV and reinstall with a fresh coat.

[Beancounter]

Rick
I used the 3/4 x 1/4 ACS shields for my throttle and mixture. In the end I opened up the 1/4 hole a little as I felt it was to close to chafing the cable. I also stuck a little patch of that ceramic fiber blanket material between the shield and the rubber grommet. In my opinion these particular ACS shields are made out of very thin material.

[apkp777]

Hello Rick,

I happened to be working on the FW grommets myself today. I ordered the Vans EYEBALL SE961-125S. These are steal and the hole comes 1/8 and needs to be opened up to about .25".

The only issue is that the print shows the holes in the FW as being 1" apart (4 7/8 and 5 7/8 "Y"axis). The grommets are 1.5" in diameter so the holes will have to be a bit further apart. I don't see any issues with that however. I forgot about carb heat so I have to order one more. I swear I should own stock in FedEx.

I actually fooled around with it today and set it aside for tomorrow. I am planning on installing them in the morning.