Firewall mount & penetration locations

[sbalmos]

Hi all,

TIme to throw myself to the wolves again. I'm laying out where everything should mount on my firewall, and the penetrations for them. I am basing it somewhat on the standard fuel-injected penetrations and battery locations. For reference, I have 2 EarthX batteries, the full EFII ignition/injection system, and the EFII Bus Manager (thus the 2 batteries and starter contactors), feeding a conical mount IO-320.

The battery boxes are pretty close to where the plans would have you mounting the PC-680 box(es). The inboard two bolt holes match to rivets to be removed from the vertical firewall stiffeners. The outbound holes are close enough to the diagonal stiffener, I feel, to not need doublers, given the feathery EarthX battery weight.

The throttle cable penetration is the standard fuel-injected throttle penetration. The fuel intake hole, return line hole, and location of EFII fuel pressure regulator, would enter where it would be an easy turn through the center tunnel cover side notches.

I think I'm most interested in the positioning of the ANL fuses and ammeter shunts, maybe also the starter contactors. I didn't really see any guidance anywhere, so I threw them where I think it might be logical, aligning them so they're connected with copper bars?

Thanks for the inevitable opinions. Hopefully not many WTFs and head-scratchers here.

[David Paule]

I don't know a single thing about your fuel system so this might be way off the mark. If so, please disregard it.

I'd attempt to place as much of the fuel system in the cabin as I could, or at any rate away from the engine bay. My thinking is that any complexity in the engine compartment increases the opportunity for a leak that could lead to a fire.

Along the same lines, I wouldn't mount fuel-related components on the firewall on the cabin side.

Dave

[Rupester]

I have an IO-320 vertical induction with Silverhawk FI. The throttle cable location showed on the plans was fine. The mixture cable location shown was unworkable. Even with the longest mixture cable Vans offers, it would not reach the mixture arm on the L side of the servo. I moved the firewall penetration to the top angled surface of the firewall inset and that worked well. I reused the original Vans mixture penetration spot for the alternate air cable.

[sbalmos]

Terry, yeah, don't have to worry about mixture with EFII. Though I don't think I left a penetration open for alt air. I'll have to think about that one.

David, the EFII system has its fuel regulator on the engine side of the firewall. That's normal. Electric fuel pumps and everything else are all inside.

I still think I'm most concerned about the placement of the fuses and shunts.