What is CHT used for?

A Cylinder Head Temperature gauge (CHT) measures the cylinder head temperature of an engine. Commonly used on air-cooled engines, the head temperature gauge displays the work that the engine is performing more quickly than an oil or water temperature gauge.

What does high CHT mean?

High CHTs generally indicate that the engine is under excessive stress for its own good. That’s why it’s so important to manage the powerplant in a fashion that limits CHTs to a tolerable value. For Bonanzas and Barons, a reasonable rule-of-thumb is that optimum engine longevity is achieved by limiting CHTs to 380°F.

What is CHT in aviation?

CHT (cylinder head temperature) Air cooled engines have a Ram air box which is installed (both sides) over the heads. The natural airflow over the heads, part of the cylinders and between the cooling fins cool down the head and the cylinder.

What causes high CHT?

The CHT is grossly, abnormally high. Either there’s some type of very abnormal combustion process going on in the cylinder (and certainly, pre-ignition should be considered with such a high CHT), or there is abnormally high friction in the cylinder, or the probe is being subjected to unusual heating.

What is a CHT sensor?

CHT sensors (Cylinder Head Temp.) are used to measure and indicate the temperature of Cylinder heads. In this category you can choose from a variety of different CHT sensors of different lengths, mountings and manufacturers. Such an indicator can prevent serious engine damage.

What causes low CHT?

An exhaust valve that’s not fully closing can cause low CHTs – your mechanic can confirm this with a borescope (or a compression test — they’ll hear air escaping through the exhaust if the valve isn’t closing).

How do you lower CHT?

Operate lean-of-peak Figure 1 shows that you can reduce CHTs by 25°F by leaning to about 10°F LOP. For each additional 10°F of CHT reduction, you need to lean an additional 15°F LOP. Using these very lean mixtures, you can go fast, stay cool, and obtain outstanding fuel economy, all at the same time.

What is EGT and CHT?

CHT gauge or monitor measures heat energy wasted during the power stroke. At this stage, the cylinder is under maximum stress from high internal pressures and temperatures. The EGT gauge or monitor measures heat energy wasted during the exhaust stroke, when the cylinder is under relatively low stress.

What is a good cylinder head temperature?

According to the engine manual, the maximum allowable cylinder head temperature (red line limit) is 500 degrees F. Lycoming states flatly that the maximum redline cylinder head temperature limit must never be exceeded. For a longer engine life, the recommendation is that a maximum 435 degrees F.