For many counterpeople, selling engine parts is no different than selling any other automotive replacement part: You identify the year, make, model and engine application, then look up the parts, right? That's the basic process in a nutshell. But with engine parts, it isn't always so simple.
Most engine components are not replaced separately. A customer can install a set of rings or bearings in a high-mileage engine to "freshen it up" a bit, but in most cases an engine that needs rings or bearings will likely need a lot of other parts, too - especially gaskets. It will probably need a partial or complete overhaul - and that means looking up a lot of individual parts.
The other thing that makes engine parts unique from other product lines is that engine components are part of a system. Bearings, connecting rods, pistons and rings are all part of the short block assembly. The camshaft, lifters or followers and timing gears, chain or belt are part of the valvetrain, as are the valves, springs, retainers and guides. As such, the parts must be properly matched.
Flat tappet cams require flat tappet lifters. Roller cams require roller lifters. Certain ring styles require certain piston configurations. Oversized cylinder bores obviously require oversized pistons and rings. A crankshaft that has been ground undersize needs oversized rod and main bearings. Each component must match and work with its companion components within the engine, otherwise the engine is going to experience major problems (increased wear, oil burning, noise, low oil pressure, etc.). So the importance of making sure each and every engine component is properly matched with the rest of the engine's components can't be emphasized enough.
On some engines, just finding the correct piston and ring combination can be a challenge. GM made numerous ring and piston changes during the late 1980s as it changed to low tension rings. This created a confusing array of possible ring and piston combinations that increases the risk of mismatched parts. It's relatively easy to install the wrong rings on a piston (narrow rings on a piston with grooves for deeper rings), but not so easy to undo the consequences of such a mistake (oil burning and high oil consumption).
On newer engines, changes in materials can create "hidden" dangers that are not readily apparent to the naked eye. Many newer engines use powdered metal valve guides rather than cast iron or bronze guides. They look the same but the powdered metal guides are much harder. The new high-tech guides are made by sintering (melting) various metal powders together to achieve special properties, including built-in lubricity. This allows much tighter clearances between the guides and valves to reduce emissions and oil consumption. It also means less oil lubrication is needed at the guides. Consequently, if ordinary cast-iron guides are used to replace powdered metal guides, the lack of lubrication may lead to valve stem galling and premature wear.
The same goes for ring sets in some of today's high-output engines. For increased durability, some top compression rings are now made of ductile iron or steel rather than cast iron. Substituting a standard ring (even if it has the same moly facing) will increase the risk of ring breakage and failure.
Unless you know the particulars for a given engine application, there's no way of knowing which replacement parts may or may not work in that engine. The parts may fit physically, but if they are not the correct material or design, durability and performance will suffer.
The Kit Approach
One way to eliminate most of the guesswork that goes with selling engine parts is to sell engine kits. Assuming the engine kit supplier has done their homework, the parts included should be properly matched and correct for the engine application. Even so, keep in mind that an "economy" kit is not going to contain the same level of quality parts as a "premium" engine kit: You get what you pay for. If reliability and dependability are important to you and your customer, forget the economy kits. Recommend a premium kit with top-quality parts. After all, rebuilding an engine is a major investment in time and money. Why take unnecessary risks by trying to save a few bucks on parts?
Most counterpeople like engine kits because kits save time. They eliminate the need to look up each and every individual part. All the parts commonly needed to do a particular repair are included in one box under a single part number. Once you've identified the year, make, model and engine application, you only have to look up whichever kit your customer wants.
In addition to convenience, another benefit that kits provide is one-stop sourcing. Most, or all, of the parts in the box come from a single supplier. This eliminates worries about mismatched components, which can sometimes be a problem when sourcing individual engine components from a variety of different suppliers. Having a single source also makes resolving any warranty issues easier, too.
Speaking of warranties, many kits offer excellent warranties. One leading aftermarket engine component supplier introduced a special premium engine kit program two years ago with a 100,000 mile warranty. It covers all the parts installed by a professional technician or engine rebuilder plus labor. The warranty even includes maintenance items such as oil, antifreeze, belts, hoses and filter elements that may be damaged as a result of an engine part failure. To qualify, the parts must be properly installed by the professional engine builder (correct surface finish on block, crankshaft and heads, proper assembly tolerances, procedures and adjustments). The engine must also be correctly installed in the customer's vehicle (everything checked, fluid levels full, proper break-in procedure, etc.), and the vehicle owner must follow normal maintenance schedules. Excluded are failures caused by abuse, racing, loss of coolant or lubrication.