FW accessories

[mototopo]

I'm assembling the firewall and I'd like to prepare it for the installation of all the major accessories before final assembly.. I think it's easier to do it now instead then once the FW is installed on the fuse.

For this reason I'm going to order from Van's the following items:

1. PC680 battery installation tray/kit
2. Gascolator doubler (I'll install an Andair gascolator later but I think installing the doubler now is a good idea)
3. Master relay and starter contactor

What else do I need?
I'm planning the engine will be a IO-360-M1B or -A1B6 (CS)
Do the holes for cables, fuel lines, wires etc. as shown on DWG 19 fit well or is better to drill the holes later?

Last question: which kind of metal grommets works best? On Van's accessory catalog there are 3 models: one hole, aluminium and steel bulkead fittings. Any suggestion?

Thanks

 

[rzbill]

Slow down

If you leave the firewall recess out of the firewall until late in construction, there is really no problem installing firewall stuff much later in the construction process.

Your e-mail indicates you have not fully researched your firewall hardware requirements. The holes through the firewall shown in the drawings you have are for a carburetted engine, not the -M1B. You need to talk to Vans to get the correct firewall penetration drawing for the M1B.

 

[mototopo]

Thank you Bill,
I already planned to leave the recess out until late in the construction process. By the way, on DWG19 there are indication for both carbureted or FI engines for throttle, prop and mixture control cables holes.

 

[shuttle]

Hi Claudio,
The -7 I'm building has an -M1B too and the Van's IO FW plans passthru locations seem pretty good. I went for a quickbuild so my FW was installed from the get go. Working on the FW after it's rivetted to the fuselage does not present many issues.

Van's IO engine FW plans do not include a gascolator (a gascolator is only in Van's carb'd engine plans) so if you put the gascolator on the Van's gascolator doubler then you will need to follow the carbed engine fuel line routing and need a slightly longer fuel hose (than in the -M1B FWF kit) from the gascolator to the engine-driven fuel pump.

I used an Andair gascolator too but positioned it in the right wingroot (away from the hot cowling area). My fuel line routing goes from tanks-to-selector-to-wing root gascolator-back to-electric fuel pump-etc. As a result I've been able to use the standard IO engine FW fuel line passthru location.

For some items, e.g. my Andair air/oil separator and condensation trap, it is much better to determine their locations once the engine and mount are installed.

You will also need a cable passthru for the Alternate Air control and, yet another one if you opt for the Van's Oil Cooler Shutter with cockpit control.

For wiring, I went for two SafeAir1 passthrus (top left and top right of FW). I also opted for the stainless steel heat bypass valve from Plane Innovations.

Hope that helps.