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Cylinder Head Temperature Gauge

A very valuable gadget to have is a CHT gauge. This will give you a relative reading of how well your engine is cooling. There seems to be no hard and fast rule of what is a good temperature, however it is obvious that hotter engines can lead to heat seizures. A CHT will quickly tell you if a new fuel is bad or if some modification you have done is causing your engine to run hotter.

Roughly a Vespa engine will run at between 320F and 380F, different engine set-ups will run different temperatures. The CHT is not a replacement for listening for engine problems (you are unlikely to be staring at it constantly), however it will tell you when to listen more carefully or not.

./Cht gauge.jpg

Pictured above Exhaust Gas and Cyclinder Head Temp Gauges. The hardest part was making the hole in the glovebox, I made a bit of a mess but most of what you see in the pic is due to dodgey touchup paint. Cyclinder Head Temp Gauges supplied to me by http://www.wadeair.com.au/

Tips:

  • straighten out a coat hanger and push that through the frame, through the clutch cable hole.
  • label the wires from each sender (because they are both the same colour
  • when drilling the hole in the glovebox, I found taking short jabs, made it easy to get the teeth cutting in the same spot

Notes:

  • EGT changes quickly with engine speed
  • CHT change slowly

Although the above is not detailed, the following links will show you all you need to know about fitting a CHT

Cylinder head temperature gauge installation

Installing a Cylinder Head Temperature Gauge

Alternative CHT

One experience with the Westach gauge was that it lost accuracy after a while and started reading high. The gauge was replaced with the following more accurate guage

MICRO 1000 CHT
http://www.aircraftspruce.com/catalo...HT_gauges2.php


http://www.aircraftspruce.com/catalo...1chtPROBES.php


http://www.aircraftspruce.com/catalo...o1chtLEADS.php

Exhaust Gas Temperature Gauges

The gauge above has a EGT (Exhaust Gas Temp), this may be very valuable for a mircolight aircraft where the engine runs at a constant RPM. In that case the EGT will quickly tell you if the engine is in trouble. However, the EGT reading changes quickly with RPM, so for a scooter it's use is limited. It "might" prove a useful tuning tool in conjunction with a rev counter.

More Information?

It would be nice to find the following information:

  • Is there a digital CHT with programmable warning light or beeper?
  • Is there a cheap digital CHT with backlight?
  • Is there a EGT/RPM gauge?
  • Is there a cheap CHT temperature switch? It would be nice to switch something off/on to save the engine
Ċ
2STref.pdf
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Paul McIntosh,
Mar 25, 2015, 1:57 AM
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Paul McIntosh,
Mar 25, 2015, 1:57 AM
ą
Paul McIntosh,
Mar 25, 2015, 1:57 AM
ą
Paul McIntosh,
Mar 25, 2015, 1:57 AM
ą
Paul McIntosh,
Mar 25, 2015, 1:57 AM
ą
Paul McIntosh,
Mar 25, 2015, 1:57 AM
ą
Paul McIntosh,
Mar 25, 2015, 1:57 AM
ą
Paul McIntosh,
Mar 25, 2015, 1:57 AM
ą
Paul McIntosh,
Mar 25, 2015, 1:57 AM
ċ
Paul McIntosh,
Mar 25, 2015, 1:57 AM
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