4 CHT sensor location

by Josh Esser in 912 / 914 Technical Questions 6 years ago

Page 2 of 2

Start
Prev
1
2
Next
End

Re: 4 CHT sensor location

by Bill Hertzel » 6 years ago

Bill Hertzel

13 1.95k 7.97k

That would mean you have the "Old" style cylinders.
The Probes are "Dry" in these cylinders and will show slightly more variation than the Newer Cylinders where the probes are actually wetted by the coolant.
Typically the #4 cylinder runs slightly hotter than the other three because it is the farthest to the rear and gets its airflow blocked the most.
The Cylinder Temperature is overwhelmingly determined by the liquid coolant and not the airflow.
Even if the plugs go dead on a single cylinder, the cylinder will not go ice cold as the circulating coolant will tend to heat it up.

The good news is that all 4 cylinders have a spot to mount a probe.
The unused ports just have a plug in them that can be removed.

I know you will insist to measure all four.
As others have stated don't expect to see a lot of difference between cylinders.
The EIS4000 was designed with Air Cooled cylinders in mind.
The Water cooled cylinders get all their cylinder heat blended together.
Where a Lycoming has a CHT RedLine of 500°F and normal operation at 350-400°F;
Your Rotax has a RedLine of 275 °F and normally operates in the 200-220°F range.

As discussed in another thread, The full volume of coolant makes a complete circuit in well under 10 seconds.
The temperature tends to be the same everywhere.
Even the radiator is only a very few degrees cooler than the hottest cylinder head.

Bill Hertzel
Rotax 912is
North Ridgeville, OH, USA
Clicking the "Thank You" is Always Appreciated by Everyone.

Report
Re: 4 CHT sensor location

by Josh Esser » 6 years ago

Josh Esser

4 6 0

Thanks for the informative response Bill. That all makes sense.

Report

Page 2 of 2

Start
Prev
1
2
Next
End

You do not have permissions to reply to this topic.

Title	Category	Replies
CHT probe type	912 / 914 Technical Questions	3
Return fuel location	915iS Technical Questions	4
912 ULS CHT, or CT?	912 / 914 Technical Questions	11
CRANK SENSOR FAULT	912iS Technical Questions	6
Intake Manifold - Pressure/Temperature Sensor Fault	912iS Technical Questions	1

4 CHT sensor location

Recent Videos

Safety First!

ROTALK News

Prize Giveaway!

Log In/Out

Login