What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

What are the odds?

rv3flier

Well Known Member
What are the odds that two days after flying with no issues, that upon turning on the master sw, there's no clacking noise indicating that the Facet fuel pump is working. So, then I start the engine using it's fuel pump only and my oil pressure reads "0" ziltch, nada. Two failures at once and apparently unrelated.

Too bad the RV-12 design didn't include and isolation shut off between the fuel tank and the fuel pump. It makes a relatively simple job very time consuming.

Then, I find that Rotax has changed the supplier for the pressure sender and that, while the new Keller sender and it's wiring harness can be had from Aircraft Spruce in europe for $190, Lockwood wants $360 !!!! It feels like being held hostage.

OK, rant over.

Has anyone noted that the new Keller sender uses the bottom of its range of 4 ohms to show .75 BAR (about 11 psi) and not Zero like the old Honeywell unit. So, if you lose all oil pressure you'll still show 11 psi. What have others done to account for this?
 
Before you pull the pump, tap it on the top with a hammer. There may be a small particle stuck in the diaphragm. It's worth a try before draining the tank et al.
 
Has anyone noted that the new Keller sender uses the bottom of its range of 4 ohms to show .75 BAR (about 11 psi) and not Zero like the old Honeywell unit. So, if you lose all oil pressure you'll still show 11 psi. What have others done to account for this?

I haven't done any work with this sensor but the low end resistance value shouldn't effect what the display indicates.
Each oil pressure sensor used with Skyview has its own associated mapping file.
If Dynon has done one for that sensor, what ever the sensor value is at zero, Skyview should be able to recognize that and display the value correctly.
It is very similar to the calibration process for the fuel level sensor, except that the values for the sensor are already established and are part of the sensor file.
 
Thanks F1Rocket, I'll give the hammer a try.

Jetguy, that unit is no longer offered by Lockwood, but thanks for the thought.

Rvbuilder2002, I called Dynon about the change, but was only told that they hadn't gotten any feedback on those that have the newer Keller sender. They thought it was just a drop in replacement. I wouldn't have even thought of it but there was a discussion on the Rotax forum from which I got my information. FWIW: http://joomla.rotax-owner.com/en/ro...ender-rotax-p-n-456-180?limitstart=0&start=20

Thanks for the follow up guys.
 
I replaced a friend's Honeywell sender with a Kavlico sender($85 at Aircraft Spruce). One hour job. worked perfect first time.
 
From Dynon EMS pressure sensor documentation addendum Revision B July, 2012, Flight DEK-180 will not display zero when connected to a Kavilco (and I assume the Keller) oil pressure sender. Instead they will read the minimum measurable pressure which is 12 psi with a 150 psi sensor. Given the difference in price and no need to use an adapter (1/8" NPT to 10 x1.0 mm) for the Keller, the Kavlico at $87 looks to be a good alternative.

It looks like the Kavlico is a three wire, +5vdc, sense wire, and ground, will require two additional connections to the EMS.

Thanks for the tip, jlfernan. I seem to remember something about a 100 ohm resistor off of pin 6 -- if so, did that require removal?
 
F1rocket, You're the man! If all else fails, get a hammer. It worked! Thanks for the tip.

John
 
Harrumph! We engineers refer to this as mechanical agitation!😜

Gotta tell a sea story: I was a junior officer on a nuke sub in the 70's eager to absorb all the info I could. The tech manual on the reactor core said the control rod blades were rattling in their guide channels so "mechanical bias" was applied. -- They bent the blades so they contacted the guide channels. "Mechanical bias" has remained my favorite engineering euphemism!
 
What are the odds that two days after flying with no issues, that upon turning on the master sw, there's no clacking noise indicating that the Facet fuel pump is working. So, then I start the engine using it's fuel pump only and my oil pressure reads "0" ziltch, nada. Two failures at once and apparently unrelated.

Too bad the RV-12 design didn't include and isolation shut off between the fuel tank and the fuel pump. It makes a relatively simple job very time consuming.

Then, I find that Rotax has changed the supplier for the pressure sender and that, while the new Keller sender and it's wiring harness can be had from Aircraft Spruce in europe for $190, Lockwood wants $360 !!!! It feels like being held hostage.

OK, rant over.

Has anyone noted that the new Keller sender uses the bottom of its range of 4 ohms to show .75 BAR (about 11 psi) and not Zero like the old Honeywell unit. So, if you lose all oil pressure you'll still show 11 psi. What have others done to account for this?
We saw this post and thought we could offer up some helpful information that was obtained from the Customer Service Department at California Power Systems.

There is a lot of confusion about the oil pressure senders on Rotax 912 series engines. Originally the engine came with a VDO sending unit, that sender was prone to failure and replaced.

Rotax started using the Honeywell sender and that was a very solid unit with few malfunctions. The Honeywell transducer produced a different signal than the VDO transducer, and the wires were permanently molded into the sending unit requiring rewiring to the gauge when the sender was replaced. Honeywell did not want that transducer used on aircraft so they stopped supplying it to Rotax for use on aircraft engines.

The newest oil pressure transducer is made by Keller, and produces the same signal as the Honeywell sensor, so no reprogramming of the EFIS is required. Another benefit of the Keller unit is that it includes a connector at the sending unit, so running wires to the gauge is not required when replaced the sending unit. One major difference between the Honeywell and the Keller is the thread size. The Honeywell has a 1/8" NPT thread and the Keller has a 10mm thread. This is important to know since you can get the 10mm thread to start in the 1/8" NPT hole damaging the oil pump housing. Rotax has published instruction on installing the Keller sender in older oil pumps, its chapter 79 in SI-912-020R8 (link below).

Those are the only three sending units that have ever been supplied by Rotax for the 912 series engines. There are many other sending units available that will work and are popular options because they are priced lower and work without issue. We do sell them through our website and there are some links below.

Service Instruction SI-912-020R8
http://docusearch.flyrotax.com/files/pdf/d05601.pdf

Replacement VDO type oil pressure sending unit:
http://www.cps-parts.com/catalog/inpages/mglopvdo.php

Rotax supplied Keller sending unit and wire/connector assembly
http://www.cps-parts.com/catalog/rtxpages/oilpressuresensor.php
http://www.cps-parts.com/catalog/rtxpages/wireassembly.php

Alternative to Keller sending unit made by Falcon with 1/8"NPT thread
http://www.cps-parts.com/catalog/inpages/falconoilpressure.php

Any questions about this can be directed to Customer Service at California Power Systems, the West Coast Rotax Service Center.
www.cps-parts.com , [email protected]
 
Thanks all, I ordered and received the Kavlico unit from Aircraft Spruce yesterday. My Dynon's last update was 5.4 - apparently there's a 5.4.2 update that followed that includes the Kavlico as an option. What would happen to the Dynon 180's display of oil pressure if the Kavlico unit is used without the subsequent update?
 
Back
Top