Engine Line Boring

In-Situ Machining (UK) Ltd are leading in the field of engine line boring by successfully supporting our clients over the years to help alleviate the cost and timeframe associated with replacing components after failure.

Large generating sets, marine diesel engines and compressor main bearing bores often experience damage during the failure of a crankshaft, leading to the requirement for repair or the more costly and time-consuming process of replacement.

Engine Line Boring Machine Services

Our expert engineers have access to a vast range of in-line engine boring equipment and associated laser and optical alignment tooling and accessories. This equipment covers most engine types requiring engine bedplate rejuvenation, whether a conventional bedplate layout or an under-slung configuration.

Repairs carried out by our experienced engineers can take the form of repairing individual main bearing pocket bores or using engine line boring equipment to complete a series of bores in line as necessary.

To ensure the quality of our work, we work closely with the owners and engine manufacturers to formulate a defined scope of work that conforms with OEM design standards and all with the added convenience of being conducted on-site.

Engine Line Boring

The process includes multiple services in which the Crankpin Journal’s condition is assessed. This allows a plan to be put in place for Crankpin machining operations. The program may include all or some of the following services:

Thermal Spraying

As part of our on-site machining services, we will provide high-quality thermal spraying – an excellent option for repairing damaged and worn bearing pockets.

The bores are machined out to remove all damage and then sprayed to re-build the removed material. Thermal spraying is a process in which material in the form of wire or powder is heated until it reaches a molten state. It is then projected via air or gas to deposit a layer on the receiving component. This process can be repeated multiple times to allow material to build up to the desired specification.

Laser & Optical Alignment

Over many years of experience, we have significantly improved our line boring services and developed various ways to repair bearing pocket bores per the makers’ preference.

Often bores are machined oversized, thermal sprayed and finally bored to standard size. Though rarely used, selective plating/electro-plated are other means of repair.

Sleeving of main bearing journal bores is another common method often adopted to repair damaged bores. This procedure requires the bores to be machined to allow the fitting of a make-up sleeve and then secured with a series of radially fitted screws before machining to design size. An allowance is left in the sleeve for final machining to standard size.

In each of the above repair methods,, it is only the lower half bearing bore that requires attention in the case of a conventional bedplate and the upper half bore of the under-slung engine type.

The mating bearing caps can be reused. More often than not, new bearing caps are advised and provided by the manufacturer, with the half bore having an allowance left on the diameter for final machining on assembly.

Associated repairs and procedures allied to bedplate main bearing bore work would take the form of advanced metal stitching of heat-induced cracking, milling of bearing cap fit location and possible make-up plating to remove fretting and wear.