WANTED : Jabiru Tachometer with inductive sender

[horsefeathers]

My tacho has died, and I need a working replacement, including sensor . I believe it is the inductive type sensor - Jabiru refers to it as the Type 1 sensor.

My engine is a Gen 2, with hydraulic lifters, if that helps.

 

Any offers out there?

 

 

[kgwilson]

Jabiru tachos are VDO brand so pretty common. Are you sure the tacho has died as it may just be the sensor. I buggered my sensor by overtightening it and stripped the thread so got a new one from Jabiru. The sensor is magnetic inductive (hall effect) and there are 2 tabs on the Jabiru flywheel. The gap is about 0.5mm. The tacho needs to be set up for 2 pulses per revolution. There are good instructions for setup when you install the tacho. If you are also using new wiring be sure to keep the cables away from other wires or you may get fluctuating values. I found this out the hard way.

 

Prices vary so check out what Jabiru charge & also check Ebay. There are heaps there in the Cockpit Vision range and the price is from about $180.00 to $350.00 for the 80mm (3 1/8") tacho. They are available with & without a hour meter so make sure you get the right model.

 

I have attached a copy of the installation & setup instructions FYI.

VDO Tacho Installation Instructions.pdf

Edited February 19, 2022 by kgwilson

[onetrack]

You can source 4000 RPM tachos fairly easily, but be aware these are more likely to designed for truck and industrial diesel engine use. An aircraft tacho should always be more detailed, as regards RPM markings, as compared to a regular industrial or truck tacho. I must say I'm a bit surprised at Jabirus choice of a tacho, they look pretty ordinary for an aircraft tacho.

I would most certainly take Kevins advice, a sensor failure is much more of a likelihood, than a tacho failure.

 

There's useful VDO tacho fault information in the thread below ....

 

 

Edited February 19, 2022 by onetrack
correction...

[Yenn]

I have a Vdo tacho for the Jab motor fitted in my Corby. I never used it as it seemed to need a 24 / 7 power supply. I don't have the sender. For twenty plus years I have been using a tiny tach. Well four of them actually as they die eventually.

You just coil the wire around a plug lead or the HT lead to the distributor, set the pulses pwr rev and they work nicely. Thay don't give a reading when you turn off the mag. for testing, but they are more accurate than the big round gauge.

[Bruce Tuncks]

I ran the tacho directly from the alternator ( there must have been a dropping resistor in the wire) and it worked so good that we tried it on a club plane. Alas, the indicator stopped working at 3000 rpm. Maybe a diode in the circuit would have helped. I thought at the time the pulses from the alternator were too close together but on my display it worked ok.

[Bruce Tuncks]

I like Yenn's idea, it obviously has fewer pulses.

[kgwilson]

13 minutes ago, onetrack said:

The VDO tachometers may be common, but the Jabiru VDO tachometer with its specific 3500 RPM rev range is exclusive to Jabiru, and you'll be hard-pressed to find one exactly the same, from any other source - even eBay.

You can source 3000 RPM and 4000 RPM tachos fairly easily, but be aware these are more likely to designed for truck and industrial diesel engine use. An aircraft tacho is always more detailed, as regards RPM markings, as compared to a regular industrial or truck tacho.

I would most certainly take Kevins advice, a sensor failure is much more of a likelihood, than a tacho failure.

 

There's useful VDO tacho fault information in the thread below ....

 

 

The Jabiru supplied tacho is a standard programmable VDO tacho designed for all engines. It has a 0-4000rpm range an hour meter and is configurable for Diesel or Petrol engines 2 or 4 stroke, 2 to 8 cylinders and 0.5 to 200 pulses per revolution. The analogue pointer can be calibrated to get it right comparing the values to other speed testing equipment & even a fine tuning option to allow for alternator slippage at different engine speeds.

[onetrack]

Yes, my apologies Kevin, I couldn't find any information on the Jabiru VDO tacho when I first went looking for it - apart from a U.S. site with a 3500 RPM UMA tacho, that states it's for a Jabiru.

 

https://www.chiefaircraft.com/uma-19-819-105.html

 

Then, an hour later, after much more searching, I found much more info and photos on the Jab tacho, so I corrected my post accordingly. I'm still of the opinion the VDO tacho supplied by Jabiru, is a bit deficient for an aircraft tacho.

I personally find the failure rate of todays VDO gauges far higher than it was 20 yrs ago, and I've fitted quite a few replacement gauges over many years.

 

I'm in agreement with Turbo in his last post in the following thread ...

 

 

 

Edited February 19, 2022 by onetrack

[kgwilson]

The VDO tachos installed in some Jabirus had the Jabiru logo on them so they would have been specifically ordered. I only bought the engine & it was supplied with the tacho & sender, oil pressure, oil temperature and Cylinder head temperature gauges plus a bunch of other stuff like the airbox & filter, carb heat control box, cylinder head plenums & the only extra I ordered being an expended prop flange. It was the 5th 3300 Gen 3 roller cam follower off the line built by Camit & cost $18,633.00 delivered in March 2013. Included in that price was the tacho & sender at $324.19.  Dunno what all that cost now.

 

I have replaced the oil pressure sensor on my engine. This is a VDO unit & apparently they are not the best largely because the unit is bolted to the engine and subject to all engine vibrations. The good part about it though is that there is no oil line needed so that is one less thing to fail. I was cruising along one day & the needle just pegged at maximum pressure on the gauge. I figured it was the sensor but went & landed ASAP anyway. After landing & taxiing back it worked normally again.

Edited February 19, 2022 by kgwilson

[facthunter]

So you still don't know for sure that it was the sensor?  An unreliable instrument poses problems. You can't logically ignore it so if it's suss it reduces the safety.. Nev

[kgwilson]

Maybe it was not clear. I replaced the sensor and oil pressure readings were then back to normal.

[facthunter]

Failure of oil sensors is probably at a greater rate than failure of the oil system itself. Sometimes the sensor leaks oil.  Where an oil line is plumbed to a gauge it's very small bore know as a capillary tube. This results in the instrument being sluggish in action but gives a safety aspect that oil can't leak at a high rate. Sensors mounted directly on the engine get all the vibrations. Nev

[Thruster88]

4 hours ago, facthunter said:

Failure of oil sensors is probably at a greater rate than failure of the oil system itself. Sometimes the sensor leaks oil.  Where an oil line is plumbed to a gauge it's very small bore know as a capillary tube. This results in the instrument being sluggish in action but gives a safety aspect that oil can't leak at a high rate. Sensors mounted directly on the engine get all the vibrations. Nev

The occasional failures of indicator systems can sometimes lead pilots to not believe. 

 

https://www.atsb.gov.au/publications/investigation_reports/2012/aair/ao-2012-154/

[Bruce Tuncks]

The Jabiru sender is interesting in that it is screwed directly onto the engine block against the sender instructions.

So it fails from vibrations, but it does not have the possibility of losing all the oil from a leaking hose.

I have known of 2 failures . In each case, there was no other corroborating evidence, especially the oil temperature and the cht's  , to indicate a problem.

In each case, the issue was fixed with a new sender. I have no doubt that if the sender were separated from the block with a bit of rubber hose, the senders would last longer.

 

 

[facthunter]

But then you introduce the failure of a high pressure flex oil line  into it.. Nev

[onetrack]

You never ever want to install rubber hose for major oil lines, that's a recipe for disaster. A friend had an F-250 Ford ute that was retrofitted with a Chevrolet 6.5L V8 diesel. This engine had an "oil filter relocation" kit fitted to it.

An adaptor is screwed into the oil filter recess on the 6.5L block, and a special alloy cast housing is attached to it, with two oil line hoses running from the new cast housing to the new oil filter location point.

My mates engine blew one of these hoses, and the engine pumped every skerrick of lube oil out onto the road, and the engine seized. When the oil light came on, it was "all-over, red-rover".

Nothing beats a minimum of hoses, or even a minimum of steel oil lines, when it comes to pumping vital oil around an engine. I can't see any problem with carrying a spare new sensor, and the tools to fit it, if the gauge fails.

I have never seen a remotely-mounted oil sensor, they are all screwed to the block, and have been, since oil gauges were installed. 

[facthunter]

Power steering hoses cause engine bay fires and oil up the trans dipstick tube. Some aero engines are fine without an oil cooler. Less to go wrong. Fire warning systems on transport Jets fire warnings are duplicated and tested before every flight and can even be done during flight. It's THAT important. IF you want more certainty there's nothing to stop you having two sensors in a metal manifold and having a 1- 2 switch. BOTH aren't going to fail at the one time..  Without oil pressure the motor won't last long and sometimes a blow up even damages the cowl so much the thing hardly glides or if it's a twin has no hope of flying on  one without descending continually. Anyhow a big blow up has a big fire risk, also. Nev

[horsefeathers]

Thanks to all for the responses and info.

I've tested the sensor, and according to the info on the web, and the testing procedure, the sensor is dead. 

Jabiru pointed me to a supplier of the sensor ($200+  - YIKES), as they are unable to supply a sensor at what they call a sensible price.

 

I'll order the sensor later, and see how I go. In the meantime, I'll try a tiny tacho as a substitute.

 

[lee-wave]

5 minutes ago, horsefeathers said:

Thanks to all for the responses and info.

I've tested the sensor, and according to the info on the web, and the testing procedure, the sensor is dead. 

Jabiru pointed me to a supplier of the sensor ($200+  - YIKES), as they are unable to supply a sensor at what they call a sensible price.

 

I'll order the sensor later, and see how I go. In the meantime, I'll try a tiny tacho as a substitute.

 

Before you purchase the sensor at such a ridiculous price check this out....https://cpc.farnell.com/multicomp/mcpip-t12l-001/sensor-m12-pnp-shielded-no-2m/dp/SN36994?   It should work.....

[kgwilson]

When I replaced the tacho sender it cost $49.22 plus freight, total $62.50 in July 2017 & that was from Jabiru. They can't have gone up that much. The VDO senders with part numbers are listed on the Tacho installation instructions I attached to my first post. Google those or check out the VDO web site. The sender is threaded and screws into the holder and secured with a lock nut. I overtightened the first one. & the sender housing split. Any inductive sender should work. There are only 2 wires. The only issue would be how big they are. The one suggested by Lee-wave is huge at 65mm in length with a 12mm thread size so would not fit the mounting bracket. It has an LED & a 3rd wire, unnecessary extras.

Edited February 20, 2022 by kgwilson

[onetrack]

The VDO Tacho installation instruction sheet that Kevin provided in his first post, shows the Inductive Sensor as VDO P/No 340 020.

 

This P/No appears to be an American VDO P/No only, as it does not appear on any Australian/NZ VDO catalogue. The 340 020 Sensor is 3/4" x 16tpi thread (UNF) and is 2" long.

 

The Australian and NZ VDO catalogue only list P/No's 340.007, 340.008, 340.009, and 340804007019C, as available Inductive Sensors in our neck of the woods.

 

The VDO catalogue says Sensor 340.008 is 3/4" x 16 UNF thread - while all the other Sensor P/No's are metric. However, an Australian supplier, Howards, says Sensor 340 008 is M18 x 1.5 thread. This warrants further inquiry.

 

Howards product - http://www.howardinstruments.com.au/product_details.php?productid=1231&mdid=9e9c31addebe481c078d59e6cf0bbe31

 

The AU/NZ VDO catalogue (see the bottom of page 63) - https://www.robinsoninstruments.co.nz/Down Load Page/VDO 2015 Catalogue.pdf

 

If you can wait 3 weeks or more, you could order a 340 020 sensor from the cheapest U.S. supplier that I've found - Anglers World, where it is currently on offer for US$53.95.

Anglers World estimate US$18.24 for 1st class International postage to AU, making the total US$72.19, which is AU$100.33 at todays exchange rate.

You might have to factor in another 2.5% for the currency dealers grab (such as PayPal, your bank or your CC provider) - and if you're lucky, Anglers World doesn't charge GST because they do less than $75K worth of business annually in Australia.

 

https://anglersworld.com/products/vdo-inductive-sender-magnetic-pickup-2-340-020?_atid=ynyXnkU142LZeKwHqynLED47cgileT

 

AISAT Instruments carry a VDO P/No V340 009 Inductive sensor for AU$128.65, which is an alternative. However, this Sensor has two spade type terminals, instead of the more secure thread-and-nut variety as in P/No 340 020.

 

https://www.aisat.com.au/our-products/commercial/vdo-commercial-instruments/senders-and-switches-commercial/v340-009/

 

Edited February 21, 2022 by onetrack
addendum...

[horsefeathers]

Thanks very much for the research onetrack, but the Jab needs Part Number 304-166. which is 1/4-28 UNF-2A thread size, so metric sensors are not compatible.

[facthunter]

That's a very small dia for that function, Nev

[onetrack]

O.K. So that's at a complete variance from the information that Kevin gave. RS Online can supply a suitable inductive sensor in 1/4"-28 UNF, but it's a different design to the original VDO one.

It appears that VDO P/No 304 166 is NLA. I cannot pick up any supplier or seller that is selling VDO 304 166. The VDO catalogue does not list any inductive sensor in 1/4"-28 UNF.

 

RSonline can supply 304-166 for an eye-watering AU$206, which is straight-out rort, IMO. The sensor sold by RSonline is also sold by Allied - and Allied sell it from their (U.S.) site for US$43.29.

Unfortunately, Allied are not a user-friendly site, when it comes to shipping to overseas purchasers - and I can see very little as regards their shipping policies.

 

You need to initiate a RFQ with Allied to find out what their shipping cost to Australia is - and in many cases, I find companies such as Allied rort you on shipping, as they mainly only deal with large corporate and military clients, who care little about shipping costs.

 

RSonline - Sensor 304-166 - https://au.rs-online.com/web/p/motion-control-sensors/0304166/?relevancy-data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searchHistory={"enabled"%3Atrue}

 

Allied Sensor 304166 -  https://www.alliedelec.com/product/rs-pro-by-allied/304166/70637851/

 

EDIT: - I just did more checking, and found that Allied have a menu along the top of their page that lists pages in various languages, and whether the sale is domestic or export.

I clicked on "Export-English" in that top menu, and the price then becomes US$47! You still need to initiate an RFQ with them.

 

 

Edited February 21, 2022 by onetrack
addendum...

[Yenn]

That diameter sounds about correct to me. It is the thread that is used for aviation usually. I still have the bracket on my jab engine and it definitely isn't 3/4" nor is it 18mm. Sadly the sender has been lost.

About oil senders, it is usual for the hose from engine to firewall mounted sender to have a restrictive nipple before it, to reduce the flow rate from a hose failure.