Testing Engine Valve Spring Strength with a DL850E

The intake/exhaust valves of an automobile engine play an important role in every engine cycle. The valves themselves are forced open by a cam shaft or other means. The valve springs hold the valves closed and work to keep the combustion chamber airtight. The springs should have a reasonable elastic force. If they are too strong, a great amount of force is required to open the valves, resulting in reduced output torque of the engine. If they are too weak, the valves will fail to keep the combustion chamber airtight, possibly resulting in insufficient compression or damage to the engine. It is, therefore, extremely important in the development and production of engines to measure the elasticity and strength of the valve springs at all engine speeds. The output signals of a crank position sensor and a strain gauge attached to each valve are simulated in the figures to the right. The DL850E simultaneously captures these signals for monitoring the time the valves are opened or closed and the strain on the valves. These signals are measured over a range of speeds to determine the maximum valve strain.

Tm Appli Auto07 1


  1. High Speed Sampling, Long Memory
  2. 10 MSPS on up to 16 isolated channels with as much as 50 Mwords of memory on each channel.
  3. Multiple Input Channels
  4. 16 channels configuration for monitoring intake and exhaust valves on each cylinder.
  5. Measurements Saved as File
  6. Store as many as 48,000 parameters automatically in a CSV (ASCII) file.
  7. Export to Excel
  8. Store the maximum voltage for a specific engine speed to an Excel file and then find the maximum value of all speeds.
  9. History Memory
  10. Save the last 2,000 waveform captures. The DL850E saves previously acquired waveform data in its history memory. A strain excursion missed visually is stored in the History Memory, permitting subsequent detailed review and analysis of the strain imposed on a valve.



Tm Appli Auto07 2


Related Products & Solutions

DL850E/DL850EV ScopeCorder

An all-in-one electromechanical measurement system offering the deepest measurement and analysis features to turn data into insights.