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-   -   elbow for oil press switch (https://vansairforce.net/community/showthread.php?t=159549)

JDA_BTR 04-12-2018 08:16 PM

elbow for oil press switch
 
I want to install an oil pressure switch at the sender mount fitting. (see page 43-04). I think that I can leave off the 1/8 pipe plug below the oil pressure sensor and use an elbow. The sensor is too fat to just screw right in.

Is an AN914-1D the right thing to use? Anybody tried this and found trouble?

czechsix 04-12-2018 08:43 PM

Just curious what you plan to use the switch for? Traditionally they are often used to run the Hobbs, but G3X (and presumably all the other EFIS systems) will track engine hours without needing the switch. This eliminates a couple pieces of hardware and a potential failure point that could result in dumping all your oil overboard...

JDA_BTR 04-13-2018 03:16 AM

I want an EFIS-independent timer. Just something I want I know it is old fashioned.

snopercod 04-13-2018 06:13 AM

Brennan Industries has a lot of weird fittings. http://brennaninc.com/product-catego...-and-adapters/

Tom Martin 04-13-2018 07:36 AM

While you are at it add a pressure switch for a back up idiot light on the panel. If your screen goes dark sometime at least you will know oil pressure is good to go.

C-GRVT 04-13-2018 07:38 AM

spacer
 
If you put a spacer behind the Van's manifold you will be able to screw the oil pressure switch into one of the side ports on the manifold.
Bill Brooks
Ottawa, Canada

Mark Dickens 04-13-2018 07:42 AM

This may sound a little odd, but when I designed my panel, I installed a Hobbs meter before I knew that the Skyview system tracked engine time, etc. I didn't want to install an oil pressure switch to run my superfluous mechanical Hobbs meter, so I just hooked it up to the alternator field switch power. If the engine is running, the alternator is running, so the Hobbs meter is running. It tracks the Skyview Hobbs meter exactly.

Tankerpilot75 04-13-2018 07:45 AM

Quote:

Originally Posted by czechsix (Post 1252807)
Just curious what you plan to use the switch for? Traditionally they are often used to run the Hobbs, but G3X (and presumably all the other EFIS systems) will track engine hours without needing the switch. This eliminates a couple pieces of hardware and a potential failure point that could result in dumping all your oil overboard...

I also wanted an independent means of tracking time. My RV already had a Hobbs meter in the panel but was unfortunately wired to start running whenever electrical power was turned on ( ie battery turned on). You can imagine the difference in ?hours? that quickly developed. When I bought the RV from its builder the ?tach? time was around 160+ however the Hobbs read over300.

When I checked the log book sometimes tach time was used, sometimes Hobbs and sometimes both. You could literally see the disparity grow over time. I decided to bring them back together. I purchased a new Hobbs meter, an oil pressure switch, ran the Hobbs to match current tach time, and installed both new switch and new Hobbs. Of course I noted in my log book the changes.

Now after a year and a half, time tracking difference is again occurring but it?s less than two hours difference for over 100 hours of use. This difference is due to how both are powered. Tach time begins at 650 rpm and Hobbs begins at sensing of oil pressure. For most Flight tracking I use Hobbs because it?s visible after engine shutdown. For log book entry I use both. However when someone else logs work on my RV I?ve noticed that they usually only record Hobbs - which incidentally was what occurred when the builder owned it. At least now when that happens the two are close to each other and time differences are immaterial.

I also discovered during this process that ?Tach Time? could be changed by just an EIS entry. Hobbs time changes take a lot more time and effort (see above). That?s one reason complete tracking of work in a well maintained set of log books is important. Not all owners keep good log books. Not all aircraft mechanics will turn on power to check tach time when they see a Hobbs meter.

rapid_ascent 04-13-2018 03:57 PM

Funny I was just thinking about the same thing. I want an low oil pressure idiot light so I want to use the Van's pressure switch. I was also thinking about using the elbow approach. I was also curious whether there would ever be a need to take a manual oil pressure measurement. It that case I might want a Tee instead of a 90. At the moment I'm leaning toward the just using the 90 but I was also wondering if this would separate the oil pressure sender on the manifold and the switch on the 90 far enough apart. I can't really tell without buying the parts.

salto 04-13-2018 04:57 PM

You could also put an air pressure switch in your pitot line if your just after air hours.


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