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Firewall fuel & oil sender mount

Bill Boyd

Well Known Member
The VA-168 sender mount has three ports, only two are shown used in the plans. Assuming a Lycoming and AFS/Dynon standard instrumentation, would I be okay to trim off the last, unused port section, or is this sometimes used for MAP or other sender purposes?
 
With most modern avionics you will use that third port for your MAP sensor, so don't cut it off.
 
I thought y'all might say that

- but then there's that FF1-6 plans detail showing a MAP hose run to a hole in the firewall :(:confused:

I guess it's a matter of preference?
 
- but then there's that FF1-6 plans detail showing a MAP hose run to a hole in the firewall :(:confused:

I guess it's a matter of preference?

If you are installing an old-school MAP analog gauge then I think it makes sense to run the hose directly from the engine to the gauge (e.g. through a hole in the firewall).

However if you are using an electronic MFD/EFIS system, then you need to connect the MAP sensor to the engine with a hose and then the sensor to the EFIS via wires. The MAP sensor needs to be mounted to something, so why not use the extra port in the manifold provided by Van's?

So preference as to type of instrumentation is probably the driver for how you connect to the MAP port on the engine.
 
Understand.

I have digital MAP instrumentation (GRT) and MAP tee'd off to dual P-mags on the 6A. All accomplished with 1/8" Tygon tubing and tee connectors.

I can certainly see the elegance and sturdiness of using a port location on the VA-186 to split this off and mount the sensor. (Wouldn't help any for the GRT box in my 6A, which is not a canister with a NPT nipple but a plastic project box with a barbed nipple sticking out one end and wires hanging out the other).

Thanks for helping avoid an impulse hack I'd regret.
 
I dont believe i have ever seeen a MAP sensor wirh an NPT fittiing. They usually have a 5/32 hose barb fitting and holes for mounting screws. I have never understood why people use steel reinforced hose with AN fittiings for this. Most every car ever produced used 5/32 rubber hose for vacuum applications, includimg the map sensor. Time tested and very reliable.

larry
 
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I dont believe i have ever seeen a MAP sensor wirh an NPT fittiing. They usually have a 5/32 hose barb fitting and holes for mounting screws.
larry

Take a look at the MAP sensor included in a Garmin sensor kit. No barb fittings.
 
Take a look at the MAP sensor included in a Garmin sensor kit. No barb fittings.

Thanks. Always a first for everything. I know that GRT and Dynon are barbs as well as counless auto applications I have seen.
 
I dont believe i have ever seeen a MAP sensor wirh an NPT fittiing. They usually have a 5/32 hose barb fitting and holes for mounting screws. I have never understood why people use steel reinforced hose with AN fittiings for this. Most every car ever produced used 5/32 rubber hose for vacuum applications, includimg the map sensor. Time tested and very reliable.

larry

?cause that is how it was supplied by Vans and shown in their plan set. I agree with you for the most part but I want a sturdier hose connnected to the the engine.
I have per plans thru firewall sensor now but will be using the extra port I left on the the manifold when Inchange out my mags for EI.
 
I think that approach makes sense if you are penetrating the firewall. Just didn't see the point with a simple run to a firewAll mounted sensor.

Larry
 
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