Onsite Crankshaft Repair of Yanmar Diesel Engine 6N18AL-DV | Machining of Crankshaft of Yanmar Engine

Raj Shahani — Mon, 21 Apr 2025 11:36:18 +0000

RA Power Solutions undertakes Diesel Engine Crankshaft Repair onsite without removing the crankshaft from the engine block. We use advanced equipment and technology for onsite grinding and polishing of damaged diesel engine crankshafts.

We were approached by a shipping company based in Mumbai, India, to whom we have been extending on site crankshaft grinding and Onsite Crankshaft Repair services for the last 45 years.

They approached us about the problem in the crankshaft of the YANMAR Diesel Engine model 6N18AL-DV.

Damage Crankpin with Ovality of Yanmar Diesel Engine 6N18AL-DV

THE ENGINE DETAILS ARE AS FOLLOWING:-

S. NO	Crankshaft Details
1	Engine Make	YANMAR Diesel Engine
2	Engine Model	6N18AL-DV 450 kVA
3	Crankpin Diameter Standard	145 mm
4	Crankpin Bearing Width	65 mm
5	Name of Vessel	MV MAITLI

ACTION TAKEN BY RA POWER SOLUTIONS FOR REPAIR OF CRANKSHAFT OF YANMAR DIESEL ENGINE 6N18AL-DV:-

Two technicians with an onsite crankshaft grinding machine boarded the vessel, and the crankshaft was subject to inspection.
All six crankpins were subject to calibration for taper and ovality.

THE DIMENSIONS WERE CHECKED AS PER RA POWER SOLUTIONS PROTOCOL, WHICH IS MENTIONED BELOW:-

STANDARD DIMENSION OF CRANK PIN – 145.00 MM

STANDARD /SPECIFIED NO. SIZES IN MM

SIZE OF CR PINS

	A	Aa	C	Cc	B	Bb	Min	STD	Ovality
CR-1	144.8	144.88	144.85	144.9	>144.81	144.87	144.8	145	0.20 mm
CR-2	144.84	144.87	144.88	144.89	144.88	144.87	144.84	145	0.16 mm
CR-3	144.82	144.87	144.85	144.9	144.81	144.87	>144.81	145	0.19 mm
CR-4	144.83	144.88	144.85	144.9	144.8	144.9	144.8	145	0.20 mm
CR-5	144.84	144.88	144.89	144.89	144.81	144.88	144.81	145	0.19 mm
CR-6	144.8	144.89	144.86	144.87	144.78	144.88	144.78	145	0.22 mm

We inspected the hardness of all crankpins. The readings ranged from 590 to 650 HB.
We carried out an MPI test on the crank pins to detect cracks. The test showed no cracks.
We checked the deflection of the crankshaft. The readings were within limits.

SUCCESSFUL REPAIR OF CRANKSHAFT OF YANMAR DIESEL ENGINE 6N18AL-DV:-

We observed higher ovality ranging from 0.16 to 0.22 mm. Based on this, we decided to grind all the crank pins.
We ground all the crankpins undersize by 0.40 mm as per the manufacturer’s recommendation. The final size ranged from 144.58 to 144.60 mm. We maintained a maximum ovality of 0.02 mm..

THE FINAL DIMENSIONS MAINTAINED AFTER GRINDING ARE MENTIONED BELOW:-

STANDARD DIMENSION – 145.00 MM

STANDARD /SPECIFIED NO. SIZES IN MM

SIZE OF CR PINS

A	Aa	C	Cc	B	Bb	Min	Max	Ovality
CR-1	144.6	144.59	144.59	144.58	144.6	144.59	144.58	144.6	0.02mm
CR-2	144.59	144.59	144.59	144.58	144.6	144.6	144.58	144.6	0.02mm
CR-3	144.6	144.58	144.59	144.59>	144.59	144.6	144.58	144.6	0.02mm
CR-4	144.6	144.6	144.59	144.58	144.58	144.59	144.58	144.6	0.02mm
CR-5	144.59	144.6	144.59	144.58	144.59	144.6	144.58	144.6	0.02mm
CR-6	144.6	144.59	144.58	144.58	144.6	144.59	144.58	144.6	0.02mm

Precision Repair of Yanmar Diesel Engine Crankshafts

The small crankpin bearing width requires the latest crankshaft grinding equipment which is possessed by us and we have been executing successfully the repair of the crankshaft of YANMAR Diesel Engine 6N18AL-DV and other models having small bearing length all over the world.

In our 45 years of experience we have executed successfully repair of more than ten thousand Crankshafts.We strictly maintain all tolerances stipulated by the manufacturer.

We have been executing the repairs in Laos, Lebanon, Malaysia, Maldives, Mongolia, Nepal, North Korea, Oman, Philippines, Qatar, Russia, Saudi Arabia, Singapore, South Korea, Sri Lanka, Syria, United Arab Emirates, Yemen etc.

Crankshaft Repair of Yanmar Diesel Engine 6N18AL-DV

Crankshaft Grinding of Yanmar Diesel Engine 6N18AL-DV on Board a Vessel

For more information on Onsite Crankshaft Repair, Yanmar Crankshaft Repair, onboard crankshaft repair, insitu machining equipment, crankpin journal repair, and ship crankshaft machining, contact us at rajshahani@rapowersolutions.com, info@rapowersolutions.com, or call us at +91-9582647131 or +919810012383.

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