# Inexpensive engine monitor?

Discussion in 'Instruments / Avionics / Electrical System' started by cluttonfred, Feb 14, 2018.

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1. Feb 14, 2018

### cluttonfred

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I have had my eye out for an inexpensive engine monitoring system for a four-stroke engine. Minimum requirements would be: tachometer, oil pressure, oil/water temperature, voltage gauge, fuel gauge. A single CHT would be nice for an air-cooled engine. In all cases, I would want a user-defined alarm indication for each gauge function.

For a long time, the cheapest option has been the monochrome LCD MGL Avionics Velocity E1 EMS (3-1/8" diameter, $345) or Infinity E3 EMS (2-1/4" diameter,$310). Add about $175 for the senders and you've everything covered except the fuel level but you'll need to go elsewhere for that as they don't offer a simple, basic fuel gauge, just a fuel computer almost as expensive as the EMS. Call it about$600 all in, though I am concerned that even the 3-1/8" one is a little bit too small and hard to read. It does also have a built in hourmeter, which is nice.

There are some automotive gauges that will do the job for the same price or less. Speedhut, for example, offers programmable custom gauges with warning lights and, if you go with the 3-3/8" quad gauge to group four functions at once, plus 2-5/8" tach and CHT, it works out to about \$650 all in. That's going to be a little heavier and a little more work to install than the MGL, but a lot clearer, though it does not include the hourmeter.

Does anyone know of any any other options for affordable engine monitoring with alarms at these prices or less?

2. Feb 14, 2018

### dcstrng

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I have the E1 in my parts box for whatever I get into the air (also the Flt-1 for flight). I figured to set the alarms and then get a larger warning light for each to alert me if I'm inattentive. Also planning to add steam OP and ASI for redundancy and that'll be it. With a handheld GPS and radio, there shouldn't be much in the cockpit to distract me from looking outside... Oh, duh, whisky compass... Have a LRI, but depends on how slow of a plane I end up with...

3. Feb 14, 2018

### mcrae0104

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4. Feb 14, 2018

### Pops

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Love my fuel gauges . They always tell the truth.

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5. Feb 14, 2018

### cluttonfred

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Interesting stuff in there, mcrae0104.... I had never heard that just connecting a tachometer could cause such headaches with the ignition. I had planned on all-electric engine gauges figuring that I needed power for the tachometer in any case. Yes, I know you can use a TinyTach, but that would not look right. Out of curiosity, if I did want to go entirely old school with only mechanical gauges, are there any readily available mechanical tachometers for VW engines?

6. Feb 15, 2018

### Pops

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There has been people that machined a tach drive that went in the distributor hole. Then put a 90 deg tach drive adapter on top to drive the tack cable.

7. Feb 15, 2018

### cluttonfred

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Maybe I should ask another way.... Are there any analog tachometers, even 12v, that can sense the RPM signal like the TinyTach from a wire wrapped around the ignition wire or some other indirect way? For example, I think there’s a Westach model that works off a little dynamo.

8. Feb 15, 2018

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This is the Westach unit I was looking at:
http://www.aircraftspruce.com/pages/in/tachometers_westach/west2tachs2b.php

9. Feb 15, 2018

### Victor Bravo

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Bring the gospel to the people Pops... you tell 'em !

10. Feb 15, 2018

### mcrae0104

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I don't know about readily available, but thesamba.com would be a good place to poke around and find out.

11. Feb 15, 2018

### dcstrng

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Gotta love sight-gauges... I've been trying to figure how to rig with my configuration -- for whatever reason all my projects, excepting the Buttercup which didn't have wing-tanks, have root ribs that are less that the full height of the wing-tank area (currently working on a metal-wing Cougar -- W10 wing configuration) and although it should read just fine from about 3/4 tank and below, I'm not sure it'll show full in normal flight attitude.

12. Feb 16, 2018

### Daleandee

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So far the direction of this thread appears as if someone read my mind or scoped out my panel. My desire was for a lightweight panel with the steam gauge look that would give me a lot of information (digital was even better) at a reasonable cost. I use both the MGL E-1 (engine monitor) & the Flight -2 (flight information) instrument that has a fuel flow (not currently used) and a fuel level (with installed sender that I have) available. Together there is a lot of great information that these two instruments provide. MGL singles are seen here: http://www.mglavionics.com/html/velocity_singles.html

Because the RPM reading on the MGL was erratic (I tried some suggested fixes without success) I went with a Westach 3500 RPM Tachometer (WES 2AT33-2). It has been rock steady and gives a reliable & accurate readout. For the Hobbs I installed a separate Honeywell meter but Westach makes the tachometer with a Hobbs meter built in if desired.

As a back-up to the ASI I installed a LRI (Lift Reserve Indicator) and find that I use that more than anything else for take-off and approach.

I also like Pop's recommendation as to be able to actually see the fuel level in the tank(s). The Cleanex has a fuse tank just ahead of the panel. I marked it as to its level both with the tail up (flight) and tail down (hangared). I can verify fuel before flight with a glance under the panel. In flight I can see the bottom half of the tank but it is a little tricky to get my head down that far. Mirrors are wonderful things. Still, the MGL fuel level indicator with the Princeton probe is quite accurate and I'm not prone to land with much less than an hour of fuel in the airplane.

Dale Williams
N319WF @ 6J2
Myunn - "daughter of Cleanex"
120 HP - 3.0 Corvair
Tail Wheel - Center Stick
Signature Finish 2200 Paint Job
169.4 hours / Status - Flying
Member # 109 - Florida Sonex Association

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13. Feb 16, 2018

### Pops

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When I built my Falconar F-12 in 1980 I built a fiberglass fuel tank in front of the instrument panel and being 2 place side by side I could lean to one side when flying solo and see the fuel in the tank and had the tank marked off in gallons. Had an electric gauge but always good to make sure.

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14. Feb 16, 2018

### Will Aldridge

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This is something I've been thinking about a lot lately for my plane. In his conversion manual Tracy Crook specifies 9 gauges to be included in the panel they are:
1.tach
2. oil temp
3. Oil pressure
4. Coolant temp
5. Coolant pressure
6. Battery volt meter
7. Fuel flow and totalizer
8. EGT
9. Fuel pressure

To say the real estate in the panel is limited is an understatement, and therefore a digital engine monitor is pretty much a necessity. Not to mention by the time i buy that many instruments a digital engine monitor starts becoming the cheaper option. I'd love to have sight gauges for the fuel tanks but i don't know how to do that for a low wing design.

After reading the article linked to above about digital engine monitors and their failings I'm wondering what the options are.

15. Feb 16, 2018

### rotax618

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16. Feb 16, 2018

### Will Aldridge

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I've seen that before and if it was reliable enough I'd build one and install it in my plane, but the text right at the front of the website "non mission critical components" doesn't instill a lot of faith. I consider knowing the health of the engine to be very mission critical.

17. Feb 16, 2018

### cluttonfred

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It seems to me that the disclaimer language is just an attempt to reduce his liability, not an evaluation of the reliability of the electronics.

18. Feb 16, 2018

### Will Aldridge

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Yeah I wondered if that might have been the case. Might be worth reaching out and seeing if his ems can accommodate my required instrumentation.

19. Feb 16, 2018

### rotax618

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The price is not a measure of reliability, the components inside the instrument were probably made in the same Chinese factory, and the price may only reflect the amount of liability insurance component in the price.
A few years ago a whole series of Rotax 912 (Ducati) ignition modules failed. Rotax in the US and Europe made a 2 for the price of 1 offer to the effected owners, you cant get a more critical component in a powered aircraft - the modules should have been replace at no charge.
Some friends exposed and examined the components in the modules and found that they were “only just” within voltage and temperature specifications. They built their own modules from their own improved design with Mil spec components.

20. Feb 16, 2018

### SvingenB

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That's really cool.