SonexBuilders.net

I've replaced the oil pressure sender quite a few times in 450 hours on my Jab 2200. I've also mounted it remotely in order to reduce mechanical movement which could lead to early failure. My current sender indicates a non running pressure of 1 PSI.

I see that Aircraft Spruce has a solid state oil pressure sender that may replace the VDO. https://www.aircraftspruce.ca/catalog/i ... ey=5678474

I have a GRT Engine Monitor (4000). Do any of you have any experience in making this change? What settings need changing on the GRT? How about the wiring?

Thanks!

Mervin Friesen

Mervin, I'm in the process of installing one of the Swift 150 psi senders in my 3300 powered Sonex but I've got a Dynon Skyview in the panel so whatever I have to do to get it working won't necessarily help you. The sender has three wires, 5 volt power, ground, and a signal wire. A quick scan of the GRT manual indicates there is a 4.8 volt output for some auxiliary inputs so that may work for you. I'd contact the GRT people in Michigan as they can likely tell you exactly how to hook it up as an auxiliary device.

But what caught my attention was the escalating price on the Swift sender. I bought mine a couple weeks ago for $43 and yesterday the price was $56 and today the price is $80. Seems as though someone saw that the competition is charging $130 or more for their senders. Get 'em before the price goes up again.

Art,,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,Jabiru 3300 #261

I asked Aircraft Spruce what the burst pressure rating on the 100psi Swift sensor. I got an email that they contacted the supplier, and will get back with me. I noticed that the new line of sensors of which Dynon’s 150psi oil pressure sensor is one of, have a burst rating of 2000psi. This includes the 100psi version. However, I couldn’t find the 100psi version with a NPT 1/8-27 male, which is likely why Dynon only sells the 150psi version.

On my GRT EIS 6000, I used the 4.8V excitation voltage line to the positive. Connected the return line to my common ground block, which the EIS is grounded too, and the signal line to an AUX input with a scaling factor of 65, and an offset of 19 ( which means-10).


I may add a resistor and capacitor to the signal line, as I suspect the sensor’s response time is fast enough that it’s picking up pressure pulsation.

Well Saturday - with baffles in the cowl to keep the oil cooler warm and a good preheat - all was well till I was straight and level. Oil Temp was fine - but the pressure started to pulse a little. With the sender up front in the cold airstream entering the cowl - I wonder if it is just the sender gumming up in the cold for a moment? Think I will make a little deflector plate for the sender to hide behind out of the airstream and see what happens.

Thank you Art, Paul, and Graeme,

I’ve ordered the Swift oil pressure sender. Your replies confirmed it should work. The one I ordered is 100 psi. I trust this will work.

Mervin Friesen

lpaaruule wrote:I asked Aircraft Spruce what the burst pressure rating on the 100psi Swift sensor. I got an email that they contacted the supplier, and will get back with me. I noticed that the new line of sensors of which Dynon’s 150psi oil pressure sensor is one of, have a burst rating of 2000psi.

Paul, let us know if you get an answer to the burst pressure rating. I went with the 150 psi version because that's what Dynon recommends for use with the Skyview. It's still supposed to give reliable readings at the lower pressures but I haven't finished the installation yet. The 3 wires are now routed from the panel (where the engine module is located) to the engine compartment so it will be time to do a test run soon.

Art,,,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,Jabiru 3300 #261

BTW, there are new 100 psi pressure senders that appear to be identical to the Swift for sale on ebay for $16.99 including free shipping.

Art

The Swift oil pressure sensor has a burst rating of 300% Full Scale, according to the response I received from Aircraft Spruce

lpaaruule wrote:The Swift oil pressure sensor has a burst rating of 300% Full Scale, according to the response I received from Aircraft Spruce

Thanks, Paul........the oil pressure sensors found on Ebay are also rated for either 2 or 3 times full scale before failure. That's one of the reasons I went with the 150 psi version............to get a bit higher rating. I believe that's also one of the reasons why Dynon at first went with a 150 psI unit. That is, before they had their sender upgraded to a 2,000 psi rating. We may have stumbled on the answer to the question of why the Dynon recommended sender costs so much.

Art,,,,,,,,,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,,,Jabiru 3300 #261

I guess I don’t fully understand. My cruise oil pressure with the vdo is 54 psi. Why would we need one rated for 150 psi? Or 2 to 3 times that much?

Mervin Friesen