Remanufacturing to better than new

When Jasper (Indiana) Engines & Transmissions remanufactures a family of engines or transmissions, the process starts with the new product development division researching popular powertrain products, resolving inherent design issues and determining how to improve a product’s longevity. The process continues with core disassembly; thorough cleaning; machining the block, heads, crankshaft, camshaft and connecting rods; and installation of new, qualified or improved components. The final stage is product-specific testing.

The company’s Wernsing Road facility, which is one of four, remanufactures up to 120 gasoline engines daily. To keep remanufacturing costs competitive, the goal is to qualify and reclaim as many parts from the original engine as possible. Jasper Engines & Transmissions reports that when it rejects core components, it replaces them with core parts and castings from the same engine family or new ones.

When remanufacturing an overhead cam cylinder head, the production department first oversizes cylinder head cam bores and either builds up camshaft journals or uses a cam-bearing shell in place of the material removed from the bores. Unfortunately, the time required to align camshaft housing bores for specific cylinder heads and meet the company’s production requirements proved to be an ongoing challenge.

Initially, production used right-angle heads on knee mill-type machines and short tools that fit between the cam-bearing caps, the company reported. The one-bore-at-a-time method was unreliable at maintaining concentricity from one bore to the next. Production then modified a gundrilling machine and applied a 762-mm-long (30″) single-point line boring and reaming tool. The downside was that this method required manually loading the long, heavy tools — a strenuous task for operators that eventually damaged the machine’s spindle because of excessive wear.

In addition, the manually intensive process produced more rejects than acceptable parts, so Jasper Engines & Transmissions’ production needs still were not being met.

The company determined that it needed a horizontal machining center that could handle the long boring and reaming tools. Already possessing machines built by Mazak Corp. in Florence, Kentucky, including the VC-500A/2PC, VCN-570C and VCN-530C vertical turning centers, as well as the QT-250MSY, QTN-250MSY and QTU-200 multitaskers, Jasper Engines & Transmissions chose Mazak’s HCN-6800 HMC with a two-pallet changer, 80-tool storage capacity and an automatic toolchanger that accommodates 762-mm-long tools, said Garrett Robinson, CNC specialist at Jasper Engines & Transmissions.

Also, the machine’s Mazatrol SmoothG CNC, working in tandem with probing macros that he developed, reportedly significantly reduces the risk of error in part loading and actual machining and frees operators for more value-added tasks.