A vessel operated by a well-known Malta-based shipping company experienced crankshaft damage on its Yanmar 6N18AL-DV engine while docked at Chittagong Port, Bangladesh. The company contacted RA Power Solutions for immediate assistance.
Understanding the urgency, we promptly deployed two experienced technicians along with our onsite crankshaft grinding equipment and all necessary inspection tools.
Yanmar 6N18AL-DV Engine Key Specifications:
| S. No. | Crankpin Details | |
| 1. | Engine Make | YANMAR |
| 2. | Engine Model | 6N18AL-DV |
| 3. | Crankpin Diameter Standard | 145.00 MM |
| 4. | Crankpin Bearing Width | 64.00 MM |
| 5. | Place of Execution of Grinding of Crankpin | Chittagong Port, Bangladesh |
| 6. | Name of Shipping Company | Reputable Company from Malta |
Inspection and Diagnosis
The vessel’s crew informed our technicians of a drop in lubricating oil pressure upon boarding. During further inspection, they discovered that three crankpin bearings had seized. The ship’s crew removed the connecting rods from all six crankpins to allow thorough inspection.
Key inspection findings included:
1. Embedded bearing material was cleaned from the crankpin surfaces.
2. All six crankpins were measured for wear and damage.
3. The inspection team detected excessive ovality on each crankpin, ranging from 0.60 mm to 0.70 mm.
The dimensions are given below:
| SIZE OF CR PINS BEFORE REPAIR | |||||||||
| A | Aa | C | Cc | B | Bb | Min | STD | Ovality | |
| CR-1 | 144.60 | 144.35 | 144.90 | 144.39 | 144.65 | 144.36 | 144.35 | 145.00 | 0.65 MM |
| CR-2 | 144.73 | 144.32 | 144.70 | 144.30 | 144.86 | 144.36 | 144.30 | 145.00 | 0.70 MM |
| CR-3 | 144.60 | 144.45 | 144.55 | 144.40 | 144.78 | 144.35 | 144.35 | 145.00 | 0.65 MM |
| CR-4 | 144.60 | 144.48 | 144.62 | 144.40 | 144.75 | 144.40 | 144.40 | 145.00 | 0.60 MM |
| CR-5 | 144.62 | 144.38 | 144.63 | 144.34 | 144.88 | 144.38 | 144.34 | 145.00 | 0.66 MM |
| CR-6 | 144.74 | 144.38 | 144.72 | 144.34 | 144.67 | 144.67 | 144.34 | 145.00 | 0.66 MM |
4. Crack testing (MPI process) revealed no visible cracks or surface defects.
5. Hardness testing showed slightly increased hardness on the seized crankpins.
Crankshaft Grinding Process
- Based on the inspection, the team decided to grind all six crankpins.
- To handle the narrow crankpin width of just 64.00 mm, RA Power Solutions used a custom-designed, special-purpose grinding tool developed in-house specifically for Yanmar 6N18AL-DV engines.
- After a careful grinding process, all six crankpins were ground to a final diameter of 144.20 mm, with a strict tolerance of -0.02 mm.
Supply of Undersized Bearings
RA Power Solutions supplied 0.80 mm undersized bearings for the Yanmar 6N18AL-DV engine. The engine was reassembled and put back into operation immediately.
Also, we stock a wide range of crankpin and main journal bearings, including undersize options up to 2.80 mm, and we regularly save crankshafts from being scrapped by using them.
Global Onsite Crankshaft Grinding Services
RA Power Solutions has extensive experience in onsite crankshaft repair and grinding, having completed successful jobs in Dubai, Fujairah, Qatar, Saudi Arabia, Oman, Iraq, Togo, Malta, Freetown, Egypt, Malaysia, Iran, Indonesia, Vietnam, Jordan, Tanzania, and more.
Our expert technicians are available 24/7 and, more importantly, we can dispatch them on short notice. In addition, several team members hold valid U.S. visas. visas, which enables us to serve clients in South America, the Caribbean, and other international locations with ease.
Contact Us
To conclude, for more information or to request immediate assistance with crankshaft grinding for the Yanmar 6N18AL-DV engine repair, feel free to reach out:
Email Address: rajshahani@rapowersolutions.com
info@rapowersolutions.com
Contact No.: No:+91 9582647131 | +91 9810012383.
FAQs
The damage was due to a drop in lubricating oil pressure, leading to the seizure of three crankpin bearings. This resulted in deep line marks and ovality on the crankpins.
RA Power Solutions deployed two technicians with specialized onsite crankshaft grinding equipment to Chittagong. They conducted thorough inspections, including crack testing and hardness checks, before grinding all six crankpins to a final diameter of 144.20 mm.
Each of the six crankpins exhibited excessive ovality ranging from 0.60 mm to 0.70 mm, with no visible cracks detected during the crack testing process.
RA Power Solutions first developed and then used a custom-designed, special-purpose grinding tool, specifically tailored for the Yanmar 6N18AL-DV engine. Moreover, the design perfectly accommodated the crankpin bearing width of just 64.00 mm, ensuring precise and efficient machining.
