Blurring the lines between OEM and aftermarket parts for gensets

Over the past few decades, the acceptance of replacement parts suppliers for engines used in the power generation market has evolved considerably. Today, the consistent quality, availability, coverage and warranty of products from branded aftermarket suppliers are increasingly rivalling those of their OEM counterparts.

Those attributes are often particularly essential when it comes to parts – whether OEM or branded aftermarket – for servicing gensets that supply primary or standby electric power, or are integrated with UPS systems. For example, a wide variety of industrial users require gensets for power at construction sites, mining and military operations and offshore oil rigs. On-time production and worker safety at these types of facilities is highly dependent on the reliable availability of electric power.

Many industrial users rely on gensets to provide standby power, which may be critical to continuing production, and to keep costly equipment running during blackouts. Others may use natural gas or diesel-generated power to provide electric energy as an alternative to grid power during specific hours to avoid high ‘peak’ energy costs.

In some applications, gensets are integrated with UPS to provide extended backup capability. These may include data centres, healthcare facilities and pharmaceutical labs, where continuing patient procedures, maintaining critical temperature ranges or preventing data losses are critical concerns.

The trend toward using branded aftermarket parts suppliers to maintain gensets and many other heavy-duty applications has resulted largely from the ability of some of these suppliers to deliver high-quality parts on time at competitive or even lower price points. In fact, many leading branded aftermarket suppliers are increasingly acting like OEMs, adopting advanced manufacturing and quality assurance programmes, incorporating lean manufacturing techniques or offering products individually as well as in kits and sets to facilitate engine overhauls.

Not only are these aftermarket suppliers meeting stringent OEM tolerances, but in some instances they are also providing value-added marketing and customer support services, providing excellent availability, comprehensive warranties and even parts research capabilities. Such value-added services are increasingly convincing heavy-duty users, parts resellers and service shops to source replacement parts from aftermarket suppliers.

Quality Diesel Service was one of the USA’s first independent diesel shops to offer 24/7 parts and service for Caterpillar engines to the oilfield industry. It has also established itself as a leading remanufacturer of Caterpillar engines and marine gear. “We know time is money in the oil industry, so we stock one of the largest inventories of Cat application replacement parts and remanufactured engines in our market,” says Vincent Bourgeois, parts manager. Since 1987, Quality Diesel Service has provided its Cat customers with parts from IPD, a branded aftermarket supplier of parts that were equivalent and interchangeable with OEM.

Headquartered in California, IPD manufactures and distributes a broad range of replacement parts for Caterpillar, Cummins, Detroit Diesel, Volvo and Waukesha engines. Products include such popular items as pistons, cylinder liners, valvetrain parts, engine bearings, and gaskets.

Many users and service providers say that the advanced manufacturing and quality assurance capabilities of aftermarket suppliers such as IPD has made them comparable to OEMs in terms of quality while offering the advantage of highly competitive prices. “I think an aftermarket company such as IPD has to prove themselves, so that's why they go the extra step to make sure the product is right,” Bourgeois explains.

Since 1985, Quality Diesel Service has sourced a range of parts from this supplier, including high-mortality items such as wear parts including pistons, liners, bearings, gasket kits and seals. Although quality and availability are essential to meeting Bourgeois’ requirements, he says that a somewhat lower price and comprehensive warranty are a ‘plus’ influence on his choosing IPD. He also says that this supplier has made some design improvements to replacement parts such as pistons, changes that can lead to improved service life.

Another US company, Diesel Exchange Incorporated, also uses branded aftermarket engine parts on a selected basis. Founded in 1992, the company has developed into an award-winning remanufacturer of diesel engines. For the past six years, those have included various Caterpillar models.

Among the users of gensets are customers in the construction, military, and oil & gas industries. For those and other Cat applications, Diesel Exchange has sourced parts such as cylinder kits, bearings and gasket kits from IPD. According to Steve Hendrick, Diesel Exchange president, this line provides the same quality and availability of the OEM dealer, yet also saves on costs. “We closely evaluate this supplier’s parts with those of the OEM, and they compare very well, “Hendrick says. “I think today’s technology has developed to the point where quality-conscious aftermarket suppliers can consistently produce the quality that used to be available only from the OEMs.” Other diesel genset service providers, particularly machine shops, are more aware of the manufacturing capabilities of this manufacturer.

 “We use CNC equipment in our machine shop, so we’re fully aware of the capabilities of those machines in meeting precise tolerances,” says Ted Short, owner of Wesley Machine. We know that IPD uses the latest technologies in manufacturing, inspection and other quality assurance procedures, which result in engine parts that consistently meet the tolerances and quality equal to that of the OEMs, in my opinion.”

In some cases, such suppliers also provide valuable technical services, such as answering questions about issues such as parts interchangeability. IPD parts information and applications data is also available via an online database, and failure analysis assistance information through technical bulletins and service videos.

Advancing manufacturing methods

Some aftermarket suppliers achieve brand name acceptance through quality that results from incorporating innovative methods on the production line. At IPD, for example, the company has completely redesigned its steel piston and cylinder liner production processes, incorporating lean manufacturing concepts and new production methods that ensure consistent quality, speed production throughput, and cost savings.

“All of this is aimed at providing end users with highly reliable products at a very competitive price,” says Airton Martins, IPD’s vice president of Operations. IPD’s production line uses not only state-of-the-art equipment, such as speciality four-axis CNC machines/tools and advanced quality assurance instrumentation, but also employs unique production methods that provide vital product attributes such as consistent concentricity among functional features.

For example, many suppliers manufacture pistons using separate machining operations, one for the crown area, one for grooves, one for final skirt outside diameter and so on. Martins contends that this several step process invites concentricity and balance problems. To avoid such issues, his production line performs all cutting operations in a single load to improve product quality, and is accomplished with specialised clamping fixtures that are specially designed for each product, fabricated in-house, and updated in case of product running change.

IPD also incorporates in-process quality control with custom-designed ‘universal gaging stations’ at each operation in its steel piston production line, requiring all features be checked 100% within machining cycle time without affecting productivity.

Martins adds, “In some cases, up to six gaging stations measure critical dimensions such as concentricity, groove locations, overall height and final weight.” Also, to confirm the accuracy of the gaging stations on the steel piston line, Martins requires that finished products be inspected at specified intervals in the quality assurance lab, using advanced measuring instruments.

“All of this is part of our lean enterprise programme,” Martins says. “This programme optimises production, reduces waste, minimises work-in-progress and labour, and provides tremendous overall quality improvement. Martins also notes that IPD shares production processes improvement concepts with suppliers, helping them improve and maintain consistent quality and control costs.

This trend of branded aftermarket suppliers pushing the boundaries to ensure they have comparable product is sure to continue.