ServicesMain engine inspection

Main engine inspection

Dimensional and visual inspection of cylinder liners, pistons and piston rings in large two-stroke marine engines.

Main engine inspection · AJP Marine & NemoyWatch on YouTube ↗
Video description

The video illustrates main engine inspection for marine two-stroke engines. The Omega sequence shows scanning inside a cylinder liner and a 3D reconstruction, with more than 20,000 measurement points per cylinder. Photographs show internal liner surfaces at different heights (VLI), followed by piston crown and piston ring inspection images (Saturn VRA). Ring groove clearance and coating thickness measurements (PRG-CT) complement these records. Inspection report pages present measurements, photographs and findings. AJP Marine is based in Brazil, serving South America with worldwide attendance on request. On-screen text is in English; the video has no narration.

Onboard condition assessment without vessel immobilisation

Inspection takes 10–30 minutes per liner, depending on the selected package. It can be performed in port or at anchorage.

AJP Marine, in partnership with Nemoy Orbiter, combines 3D cylinder liner measurement, internal photographic inspection and piston ring measurements to document main engine component condition. Results support maintenance planning and comparison between cylinders.

3D LDM · Omega 3D Scan

3D cylinder liner measurement

Dimensional scanning records the internal geometry of the liner around its circumference and along the inspected height. Profiles, sections and 3D views show the distribution of diameter, wear and ovality.

  • More than 20,000 measurement points per cylinder.
  • Locate dimensional variations and compare cylinders.
  • Support condition monitoring and liner replacement planning.
  • Access through scavenge ports, without cylinder-cover removal where the engine configuration permits.
First 3D view of the measured cylinder liner geometry.Second view of the same cylinder liner, showing its measured geometry from another angle.Third view of the same cylinder liner, completing the dimensional views selected from the report.
Three views of the same cylinder liner. Select the image to open the complete measurement page in a new tab.

VLI · Omega

Internal liner inspection

Borescope photographs document the liner surface at different heights and orientations. These visual records complement the dimensional measurements and help locate surface features for technical assessment.

  • Photographic records associated with each cylinder and inspected position.
  • Views of the liner wall and lubrication points.
  • Surface condition documented for assessment and follow-up.

Five vertical positions within a cylinder, from above the scavenge port to the cylinder cover.

Select a photograph to enlarge.

VRA · Saturn

Piston crown and piston ring inspection

Photographic inspection records the visible condition of the piston crown and piston rings through the available scavenge port access. Views from different positions provide a record for assessment and maintenance follow-up.

  • Images of the piston crown, ring pack and visible ring surfaces.
  • Records organised by cylinder and viewing position.
  • Visual findings considered alongside the dimensional inspection.
Complete piston ring pack visible through the scavenge ports.
Piston ring pack
Detailed photograph of the first piston ring and the adjacent piston surfaces.
Ring 1
Detailed photograph of the second piston ring and the adjacent piston surfaces.
Ring 2
Detailed photograph of the third piston ring and the adjacent piston surfaces.
Ring 3

Piston ring pack and individual ring details from a cylinder.

Select a photograph to enlarge.

PRG-CT

Ring groove clearance and coating thickness

Measurements of the clearance between the piston ring and its groove, and of the ring coating thickness, complement the photographic inspection.

  • PRG — Clearance between the piston ring and its groove.
  • CT — Piston ring coating thickness.
  • Measured values recorded for assessment against applicable manufacturer limits.

Inspection report

Measurements and photographic records are organised by engine and cylinder, with findings and condition comments for the vessel’s engineering team and technical management.

Report content reflects the agreed inspection scope and available data.

  • Liner profiles, sections and 3D views from the dimensional scan.
  • Photographic records of liner surfaces, piston crowns and piston rings.
  • Ring groove clearances and coating thickness measurements.
  • Condition assessment and recommendations for maintenance follow-up.

Selected pages show how the results are presented, from the engine overview to measurements and photographic records for individual cylinders.

Select a page to open the full-size image in a new tab.

Report overview with comparative cylinder charts, wear profiles and 3D liner representations.
Engine overviewComparison of cylinder condition, principal measurements and 3D views.
Report page with technical comments on liner, piston and combustion chamber condition.
Technical assessmentInspection findings and comments on component condition.
Condition table comparing liner measurements, piston and ring condition, groove clearances and coating thickness across five cylinders.
Condition and measurementsConsolidated results, ring groove clearances and coating thickness.
Cylinder measurement page with diameter and wear profiles, polar sections, 3D views and a separate temperature map.
3D liner measurementsDimensional profiles, polar sections and views of an individual liner.
VLI report page with a photographic grid showing the upper chamber and liner surfaces at different positions.
Liner photographic recordsVLI images arranged by inspected region and viewing position.
Saturn report page with photographs of individual rings, piston views and charts of ring groove clearance and coating thickness.
Piston and ring recordsSaturn images with ring details, overall views and measurement charts.

Engine types and compatibility

Main engine inspection for large two-stroke marine engines with cylinder bore diameters from 400 to 980 mm. Engine makes and families include:

  • MAN B&W / Everllence B&W
  • WinGD
  • Sulzer / Wärtsilä RT
  • UEC — Mitsubishi / Japan Engine Corporation

Compatibility is checked for the specific engine model, cylinder dimensions, access arrangements and selected inspection package before attendance.

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