Home > VansAirForceForums

- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

Old 06-08-2018, 05:16 PM
JDA_BTR JDA_BTR is offline
Join Date: Dec 2013
Location: Baton Rouge, LA
Posts: 673
Default Firewall penetration question

With the fm150 should all the cables come through the middle penetration? Or does the governor go through the left? Or?

Do the cylinder and egt temp lines run best thru middle or left? Same question for red cube? My GEA24 is on the left sub-panel
Ser 104142, RV-14A
Final Assembly....
Reply With Quote
Old 06-08-2018, 06:03 PM
Mark33 Mark33 is offline
Join Date: May 2010
Location: Baton Rouge, La.
Posts: 470
Default P.M.

I just sent you a P.M.
Reply With Quote
Old 06-09-2018, 01:59 AM
JHartline JHartline is offline
Join Date: Dec 2012
Location: Carrollton, GA 5GA2
Posts: 185

I routed the control cables as depicted in the plans. Using the mounting bracket from Airflow the cable lengths are correct. See a related thread about how to mount the bracket if you havenít done that part yet.

My GEA24 is on the right subpanel. I split the EGT & CHT into two bundles, motor right and left, and ran them through the openings on their respective sides. I would think thereís plenty of wire length to do it however it works best for you. I believe I ran my fuel flow wire through the left side.
James Hartline
Carrollton, GA 5GA2
RV-14 - Hoping to fly sometime this century. Almost done.
T-Bolt IO-390
Maule MX7-180
Reply With Quote
Old 11-08-2018, 09:51 PM
JDA_BTR JDA_BTR is offline
Join Date: Dec 2013
Location: Baton Rouge, LA
Posts: 673

Iím going to put in another firewall penetration using the Avery kit. I was planning to put it above or below the fuel and oil pressure block and a little left.

Is there a reason not to put a penetration higher on the top part of the firewall or is lower better? Might put it in the space behind where the left top engine mount tubes come together. 14a.
Ser 104142, RV-14A
Final Assembly....
Reply With Quote
Old 11-09-2018, 06:22 AM
Tom023 Tom023 is offline
Join Date: Jul 2011
Location: Cypress, TX
Posts: 262

I did a combination of the previous responses. I ran control cables as plans and also have the FM150. Split engine left and right and used both pass throughs. I added a 1/2” third pass through below the upper left engine mount specifically for power cables.
RV14A #140083
Down to last 5%.
2018 Donation

Last edited by Tom023 : 11-09-2018 at 08:50 AM.
Reply With Quote
Old 11-09-2018, 07:41 AM
DanH's Avatar
DanH DanH is online now
Join Date: Oct 2005
Location: 08A
Posts: 8,067

May I add a note here?

A tubular steel firewall pass-through filled with an intumescent sealant is very fire resistant. The sealant will also do a pretty good job of locking the components (wires, cables, etc) in relation to each other. However, that fixation is not perfect, as the sealant is elastic. It's also easy to have voids inside the tube, since flow during sealant injection is entirely random.

I've seen a few -14's with power wires, control/instrument wires, and engine push-pull cables all run through the same tube. Must be on the plans that way. This one is typical.

I think it's a bad idea.

First, the fundamental objection; Bowden cables can act like a saw. I've seen 'em cut completely through an Adel clamp. It doesn't take a lot of mis-rigging to have that Bowden pull a little with each startup, for example.

Second, note the approach angle on the big wire. It is hard against the edge of the tube at 1:00 o'clock. It will wear through the insulation there even if the tube is full of sealant.

Third, think about maintenance, or wiring changes in the future. The big control push-pull will wear out eventually. It will need to be removed through the tube, and a new push-pull inserted. If you install the push-pull with its end fittings, then install wires, will you have enough clearance to get it back out without first removing the wires?

Last, clearance issues aside, the sealant plug will need to be cut away from the interior surface of the tube in order to remove wires or cables. To do it requires using a shop-made semicircular "knife" pushed into the tube in two or three places. Here there is no clearance for the approach of the knife. The cables need to come straight out of the fitting for at least an inch or two.

I realize locating firewall passages is a challenge for some builders, so I'm not going to tell you where to put them. If you want to stick with the location(s) on the plans, that's great. However, I strongly recommend that you install separate pass-throughs for control cables and wires. It need not be complicated. Using the above as an example, just put two of them side by side. I'm sure Vans will cheerfully sell you a few more, and they're easy to weld up locally. If you wish, weld multiple tubes on the same baseplate to save real estate.
Dan Horton
Barrett IO-390
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -6. The time now is 10:14 AM.

The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.