EMD and GE Engine Spares: A Buyer's Guide

Many of the diesel-electric locomotives working in southern Africa are built around engines of EMD or GE design. When one of those engines is due for an overhaul, or a failure takes a locomotive out of service, the speed and accuracy of the parts order decides how long it stays in the shed.

This guide is for maintenance planners, buyers and workshop engineers who order engine spares. It covers the main part groups, how to identify the correct item, and how to send an enquiry that can be quoted quickly.

Two engine families, two design approaches

It helps to know which engine family you are dealing with, because parts are not interchangeable between them and the terminology differs.

• EMD engines (the 645 and 710 series are the best known) are two-stroke diesels. They use unit injectors, a turbocharger and, on many models, a power assembly made up of the cylinder liner, piston, rings, cylinder head and related parts that can be changed as one unit.
• GE engines of the FDL family are four-stroke diesels, with a separate fuel injection pump and nozzle for each cylinder and their own arrangement of heads, liners and valve gear.

Within each family there are different models, cylinder counts and production variants, so the engine model and serial number matter as much as the part number.

The main groups of engine spares

Whatever the engine, most orders fall into a handful of groups.

Power assembly components

Liners, pistons, piston rings, piston pins, cylinder heads, valves, valve guides, valve springs and the seals and gaskets that go with them. These are the parts that wear fastest under load and heat, and the ones most often replaced together during an overhaul.

Bearings and running gear

Main bearings, connecting-rod bearings, camshaft bearings, thrust washers and bushes. Bearing shells are usually ordered as sets, and standard and undersize versions must not be mixed up.

Fuel system

Unit injectors on EMD engines; injection pumps, nozzles and high-pressure lines on GE engines; plus fuel pumps, filters and fuel lines. Small dimensional or calibration differences matter here, so exact identification is essential.

Air and exhaust

Turbochargers and their internal parts, intake and exhaust manifolds, expansion joints, aftercoolers and air box parts. We cover the turbocharger separately in locomotive turbocharger parts: wear and fixes.

Lubrication and cooling

Lube oil pumps, water pumps, oil coolers, strainers, filter housings, thermostats, hoses and pipework. Some of this pipework can be made from a sample, as explained in CNC tube bending for locomotive pipework.

Gaskets, seals and fasteners

The low-cost items that most often hold up a job. A complete overhaul gasket set on the shelf is cheap insurance compared with a locomotive waiting for one missing seal.

How to identify the right part

Most delays in engine-parts orders come from incomplete or ambiguous identification. Before you ask for a price, try to collect:

1. The part number from the manufacturer's parts catalogue or the part itself. Note any revision letter or suffix.
2. The engine model and serial number, and the locomotive class and number if you know them.
3. A description in plain words, for example "connecting-rod bearing, lower, standard size".
4. Photos of the old part, including any markings, casting numbers or labels.
5. Quantities, including how many per engine and how many engines you are planning for.

Part numbers are sometimes superseded: a newer number replaces an old one, and the replacement may or may not be fully interchangeable. If your catalogue is old, say so in your enquiry so the supplier can check the current equivalent.

If you have no part number at all, a sample, a drawing or good photos with measurements can still be enough. Deomac can quote and make products from a sample, drawing or part number, which helps when a part is no longer listed anywhere.

OEM, aftermarket or re-engineered?

For engine parts you will usually choose between three routes:

• OEM parts, made or supplied by the original manufacturer's supply chain.
• Aftermarket parts, made by other manufacturers to the same pattern and function.
• Re-engineered parts, made from a sample or drawing when neither of the first two is available or practical.

Deomac supplies diesel locomotive spares as OEM or aftermarket parts through reliable partners across the globe, and its Johannesburg workshop can re-engineer and manufacture parts that are hard to find. The right route depends on the part's function, your fleet's maintenance rules and how quickly you need it. For safety-critical and high-load parts, involve your engineering team in the decision.

Plan overhauls, not emergencies

Engine spares are easier to source when they are planned. A few habits make a big difference:

• Build a kit list per overhaul type. Record which parts were actually used on the last few overhauls, not just what the manual lists, and use that to set your kit.
• Separate consumables from major items. Gaskets, seals, filters and rings are used every time; liners, heads and turbochargers less often. Stock and order them differently.
• Track lead times by part. Locally available items, imported items and items made to order all have different lead times. Your own order history is the best guide.
• Keep the removed parts until the job is closed. An old part is often the quickest way to confirm a replacement or to have it re-engineered.

What to send with your enquiry

To get a fast, accurate quote from Deomac, send:

• part numbers or drawing numbers, with descriptions and quantities;
• the engine model and, if possible, the serial number;
• photos of the old parts and their markings;
• the delivery location and the date you need the parts by;
• whether you need OEM only, or will accept aftermarket or re-engineered alternatives.

Start by checking the Deomac parts list, which you can search by Deomac number, drawing number or description; our guide on how to search the Deomac rail parts list explains how. Then send the details through the contact page, or call the Johannesburg head office.

Summary

Engine spares for EMD and GE locomotives fall into a few clear groups, but each engine family, model and variant has its own parts. Clear identification, realistic planning and an honest view of OEM, aftermarket and re-engineered options keep locomotives moving. If you are stuck on a part that nobody seems to have, the re-engineering and manufacturing services at Deomac are built for exactly that situation.