Repair of Threads in Engine Block

RA Power Solutions was informed about the serious accident of the MAN diesel engine on board a vessel sailing near a port of China. On investigation, it was observed that the cam cover of the engine block was broken into pieces and all the threads, including the dowel pins, were damaged. It was not possible to assemble the new cam cover and operate the engine.

The following was observed by RA Power Solutions technicians on investigation of the engine block:

1. 6 nos. Of the damaged threads, the cam cover is assembled on them.
2. 2 nos. Dowel pins (locating pins) were also badly damaged.

Following are the photographs that illustrate in detail the damage caused to the engine block and cam cover.

Cracked Housing

Broken Bolt

Broken Bolt Inside the Threaded Hole

Damaged Upper Threads

Housing Base

The engineers from MAN were called and advised that, given the extent of the damage, it is not possible to repair the damaged threads, which need to be replaced. RA Power Solutions was called, and after investigation, it was decided to repair the damaged threads by using helicoil thread inserts and a new dowel pin.

The job was executed by following this method:

1. The bolts, which were stuck in the engine block housing cam cover thread, were removed by the drilling process.
2. The thread-damaged area was metal-stitched and metal-locked with the use of special alloys and profile keys developed by RA Power Solutions.
3. Fresh holes of 12 mm were drilled.
4. Helicoil thread inserts were fitted.
5. The damaged locating pin/dowel pin was removed.
6. The damaged area on the engine block was metal stitched and metal locked.
7. A new hole was drilled, and a dowel pin was fitted.

Following are the pictures showing the process followed for repair of damaged threads:

Repair of Threads On Engine Block Under Process

Repair Of Thread Hole By Metal Stitching

Metal Stitching of Bottom Area of Threaded Hole to Give Extra Strength

Cam Cover Sitting Area of Engine Block After Repair

The engine block is successfully restored without the need for replacement, resulting in significant cost savings and reduced downtime for the shipowner. Through our advanced engine block repair techniques and specialized metal stitching services, the damaged threads and structural integrity of the engine block are effectively restored, ensuring reliable performance and extended service life of the engine. For more details regarding engine block repair, thread restoration, or metal stitching services, please email us at rajshahani@rapowersolutions.com or info@rapowersolutions.com, or call us at +91 9582647131 or +91 9810012383.

Our team will be pleased to assist you with expert guidance and repair solutions.