Dynamic Pressure Measurements on Ingersoll Rand 4
Cycle Engines

APPLICATION NOTES

Special care must be taken when collecting data on Ingersoll Rand KVS, KVT, KVR and KVG engines. Pressure sensors can be damaged very quickly due to the extremely hot combustion temperatures typical of these engines.

The following problems can also be typically encountered on these engines:

• Extremely high pressure peaks (spikes). This is caused by detonation in the Kiene valve passage and not in the power cylinder. The IR engines have very large pressure passages that are normally filled with a special plug. A special KIENE valve for this engine takes up much of this volume. If a standard KIENE valve is installed, the water jacket does not give sufficient cooling to the valve, and an attached sensor quickly becomes too hot. Usually, we find that standard KIENE valves are used, and therefore causes this problem.
  
• Significant thermal drift of sensor output can occur at loads approaching 90%, and at full load, drift can occur during a single cycle.
  

The following are recommendations to help minimize the above effects:

• Install the special tap designed by Kiene for these engines.
  PVG, SVG, TVR, XVG KIENE P/N V-10
  KVS KIENE P/N V-10S
  KVR, KVT KIENE P/N V-33
  
• Make sure that the valve is fully seated open. The back seal is critical because any leakage in the valve will result in an excessive temperature increase at the pressure sensor
• Do not leave the sensor mounted on the Kiene valve with the valve open for more than 15 seconds, if possible. If the sensor gets too hot to touch (at the fins) let it cool before taking more data.
• Zero the sensor between each cylinder to minimize zero drift.
  Please note that we have been informed that the V-10S Kiene valves don’t last long and that they can freeze up after several uses. But they do help to reduce the detonation in the valve passage and lowers the gas temperature at the pressure sensor.

Windrock is working on a number of software enhancements to help deal with valve passage detonation and thermal drift of the pressure sensor due to excessive heat. However, we have had good success taking data on these engines if the above recommendation are followed.

The pressure trace below shows the detonataion caused by passage detonation and distortion of the compression caused by the sensor overheating.