Basic light aircraft such as the C172, Warrior and Musketeer have never traditionally had a lot in the way of engine monitoring capability: oil temps and pressures and that’s about it.
You may have encountered the odd one fitted with an exhaust gas temperature (EGT), cylinder head temperature (CHT) or fuel flow gauge, but that would have been the exception more than the rule. And for the these sort of aeroplanes that is generally sufficient.
But when you’re flying a high-speed turbine, turbo or 300hp six cylinder that drinks enough avgas per hour to have filled the tank in the family sedan, you will need to fine tune the engine settings to get the best performance and economy.
At this level, small changes make a big difference. Enter the EMS.
In sum, the EMS is your very own flight engineer that keeps an eye on the temps and pressures for you, helps you lean the mixture for desired performance and yells out when something looks out of kilter.
Most importantly, they monitor trends so you can clearly see if something is heading outside the parameters.
The engine monitors of today are high-tech bits of equipment with some models capable of sensing temperature to 2.0 deg F and manifold pressure to 1/10th of an inch Hg.
Being able to set the engine to a finite accuracy like this might seem to be excessively fiddly, but the ability to do so can translate into extended engine life and thousands of dollars off the operating cost of the aeroplane.
That’s nothing to be sniffed at.
Ultra Electronics
US conglomerate Ultra Electronics recently bought the AuRACLE range from Xerion Avionics, bringing the CRM 2100, 2101 and 2120 into their stable.
The 2100 has been designed to replace most of the usual engine and system instruments.
The interface unit is mounted on the engine side of the firewall, which means there are less cables and ‘wet’ lines behind the panel.
All the readings for four or six-cylinder engines are shown on a 125mm colour LCD display, which has anti-reflective coated glass.
17 different parameters can be monitored including the customary RPM, MAP, EGT, CHT, temps and pressures.
Turbine inlet temperature (TIT), induction air temp and compressor discharge temp are options.
Power output calculations are provided as digital read-outs, for example, 200hp and 65 per cent, so you can see the effects of changing the engine settings.
Bugs are used on the power graphics to make it easier to set cruise, climb or descent power almost instantly.
EGT and CHT read-outs also have the lean-assist feature to make fuel mixture leaning easier and more accurate.
Both digital and graphic read-outs for all parameters are provided using colour coding for status.
The digits are nice and big, which reduces the need for peering at the panel trying to make out what it says.
As well as the engine info, the 2100 also monitors vacuum and amps.
In case of charging system failure, the 2100 will continue to work on as low as 6V.
A USB port on the bezel makes it very easy to extract the logged data.
The AuRACLE CRM 2100 has two brothers, the 2120 and the 2101.
The 2120 is a twin-engine system, where all the engine read-outs are naturally duplicated.
As this unit has two screens within a common bezel, owners have a choice of either vertical or horizontal format.
Two interface units are required, installed one in each engine nacelle.
The CRM 2101 version is capable of connecting directly to an existing JP Instruments engine monitor harness with no mods required.
All existing sensors except pressure and RPM can be re-used.
The 2101 is therefore available without any sensors if need be.
JP Instruments
JP’s baby is the EDM 700, which requires a 57mm hole in your panel.
Small it may be, but with mixture leaning, which enables accurate leaning for lean-of-peak (LOP) or rich-of-peak (ROP); EGT/CHT, voltage differential, shock cooling monitoring and hands-free auto scanning among its considerable talents, this unit certainly earns its keep.
Within the round face are six bar graphs that move up and down and the sensors in the engine pick up change.
The 700 can also be linked to a fuel flow meter so you can adjust for best range or best economy with greater accuracy.
Oil temp, TIT and OAT can also be optioned in.
A 700 9c version is also on the market specifically for those whose aeroplane is pulled along by a nine-cylinder radial engine, and a 760 twin for the multis.
JP’s EDM 900 is a much more comprehensive system, but installing it will mean kicking a bigger hole in your panel that with the 700.
Rather than switch through pages on a small display, the 900 is contained within a 130mm x 130mm box and has several monitors active at once.
It also includes MAP and RPM readings to help you set the percentage power.
Insight
Insight’s GEM 610 is an advanced engine monitoring system that builds on the performance of their 602/603 series.
It is a round 57mm type with the customary bar graph indicators, so although not large it has a lot of critical info packed into it.
As with all monitors of this type, the way the bars work takes some getting used to, so spend some time working things out on the ground to save confusion in the air.
The bars indicate the CHT and EGT temperature and the temps can be selected to either Fahrenheit or Celsius.
Above each bar is a small arrow that indicates the temperature trend of that particular cylinder, so you can immediately see if any cylinder is tending to run hotter or colder.
Mixture leaning is generally done once established in the cruise, but the 610 will allow it to be done at any time.
Once the operation is started, the 610 analyses the EGTs and indicates the leanest cylinder by causing the corresponding temperature bar to flash.
With the G3, Insight has introduced colour to the 57mm display, but it is a lot more that just pretty.
The colour does make the standard six bars (seven if you have TIT) easier to read at a glance, but the real advantage of this unit is the new features that have been built in.
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