Counterman
Search
Article > Tech

Mechanic Connection: Sourcing Engine Parts


9/21/2006
By Gary Goms

 

Because of the time and expense involved, many factors go into sourcing engine parts.

It’s a typical scenario: a late ’90s front-wheel drive van suffers a blown cylinder head gasket and the owner drives the vehicle until the engine quits.

Upon initial inspection, the engine will crank, start and run, but produces a one-half crankshaft-speed tapping noise at idle. The radiator coolant has a scorched smell and the oil on the dipstick is pitch-black. Obviously, the engine has been severely overheated and perhaps ruined. Depending upon the age, market value and overall condition of the vehicle, the shop may recommend that the owner repair or replace the engine, or that he should perhaps sell the van for salvage value.

Of course, if the customer chooses to repair or replace, the shop owner must then decide where he should source the parts. Buying individual parts from the local jobber store might prove expensive for a major rebuild. Buying rebuild parts assembled in kit form from an engine parts warehouse might be the most cost-effective method for repairing minor engine damage, but this option requires many hours of clean-up and assembly time, not to mention the risk of an out-of-pocket warranty comeback. The shop owner might choose to replace with a remanufactured engine because the turn-around on the repair is much quicker and the price might include a coast-to-coast warranty. On the other hand, the shop owner may not be able to locate a reman engine that fits this particular application. Decisions, decisions, decisions!

ENGINE ECONOMICS

Because of advances in design, metallurgy and lubrication, modern engines are capable of running 200,000 miles or more without a major failure other than experiencing an occasional intake manifold or cylinder head gasket leak. Usually, the life of a well-maintained engine extends well beyond the life of the chassis, interior accoutrements and the market value of the vehicle itself.

Because of accessibility issues, major engine repairs on modern vehicles are a very time- and capital-intensive endeavor. For most shop owners, engine replacements or rebuilds have diminished as a profit center because of decreasing demand and an increasing financial commitment for both the shop and its customer. Selling a dozen single-axle brake replacements is much more profitable and poses much less financial liability than devoting the same amount of time to replacing a single engine for a single customer.

On the other hand, engine repairs are a fact of life for any shop that maintains vehicles for a long-standing group of customers. Not many owners are willing, for example, to accept salvage value for a vehicle that has a few coupons left in the payment book. Nor are many owners willing to junk a well-maintained vehicle that has suffered an engine failure caused by an out-of-the ordinary circumstance, such as a catastrophic coolant or lubrication leak.

TECHNICAL CONSIDERATIONS

Modern, dual-overhead camshaft, 32-valve V-8 engines obviously have many more wearing parts than a conventional push rod, in-line engine. In addition, their aluminum cylinder heads are more susceptible to warpage and corrosion, while their lightweight, cast-iron engine blocks are more likely to crack.

As one might suspect, a modern engine must be restored to a much higher level of performance and durability. A poorly machined valve seat, for example, may cause a misfire condition that may turn on the vehicle’s check engine light. Similarly, an engine that consumes an above-average volume of crankcase oil will eventually contaminate the exhaust gas oxygen sensors and the catalytic converter with oil ash residue. In short, it’s tough for any technician to estimate an exact dollar cost to restore an engine to its original level of performance and reliability because of the multiplicity of parts and the sophistication of the machine work required.

ENGINE REBUILDING

In its own way, rebuilding gasoline engines is as much of an art as it is a science. An experienced engine technician learns to ‘read’ the condition and wear patterns on the parts as he disassembles an engine. Consequently, a master technician can usually deal with the root causes of a failure more effectively than can an entry-level mechanic.

A connecting rod bearing failure might, for example, be caused by a cracked block leaking coolant into the engine oil. Or a thrust bearing failure on the crankshaft might be caused by an over-pressurized and ‘ballooned’ torque converter. With that said, the relative skill of the technician and equipment level of the shop has a great influence upon whether the engine should be replaced or repaired.

In addition, availability of replacement engines also affects the decision whether to replace or rebuild. In some cases, the vehicle might be a collector or classic automobile in which replacing the ‘serial number’ engine would drastically reduce the vehicle’s value. In other cases, a replacement engine may simply not be available due to rarity or low demand. In these cases, a resourceful parts professional is invaluable.

PARTS SOURCING

Obviously, sourcing parts becomes a major factor when the choice is to rebuild, rather than to replace an engine. Generally speaking, most jobbers stock common replacement parts like gaskets, pushrods, valves or crankshaft bearings for popular small-block Ford, Chrysler, and General Motors V-8 engines.

Most shops prefer to custom-order engine rebuild parts in kit form, which may include items like gaskets, oil pump and the correctly sized crankshaft bearings, pistons, and piston rings. In practically all cases, the shop prefers a kit with brand-name, quality parts.

Editor’s Note: For more information on engine kits, see this month’s technical feature, Keeping your Bearing, which starts on page 26.

At this point, it’s important to understand that engine repair is a very time-intensive endeavor and most shop owners and technicians aren’t willing to gamble several day’s assembly time on white-box or off-shore labeled parts. Most technicians insist on major-branded parts or a part carrying a major distributor’s label because the part will meet a high standard of fit, finish and reliability. Parts that may appear identical on the counter may contain inferior materials or machining defects that can cause potentially expensive warranty headaches.

PERFORMANCE WAREHOUSES

A growing area of parts sourcing is the large performance warehouse companies that sell performance rebuilding kits that may include new crankshafts, new high-strength connecting rods, hypereutectic or forged pistons along with performance piston rings and bearings. In some cases, the performance kit may represent the better bargain due to the inclusion of a new crankshaft and higher-quality parts.

REMANUFACTURED ENGINES

Many years ago, a cylinder reboring machine and a valve refacing grinder were the only major equipment needed for rebuilding an engine. As over-head camshaft, multi-valve, aluminum cylinder head engines became more common, so did the engine rebuilding process. Unlike their cast-iron predecessors, these engines often require cylinder head welding and straightening services, along with precision valve seat and guide machining. Moreover, the thinner, light-weight cylinder blocks require precision cylinder reboring, main bearing align boring and deck resurfacing. The fact that this equipment is expensive and requires specialized skill levels has driven many independent shops away from in-shop rebuilding.

Because engine remanufacturing is a highly competitive, price-driven market, quality and warranty issues remain at the forefront of shop owner concerns. To illustrate, some remanufacturers try to salvage hard-to-find engine cores in an attempt to maintain inventory and cut core acquisition costs. In many cases, these attempts reduce the reliability of the engine. And, because some engines — import engines in particular — are so much more durable, remanufacturers continue to be challenged by a thriving used-engine market.

With that said, some remanufacturers are dealing with quality issues by consolidating coverage and spending more money on new core replacement parts. If proper remanufacturing and quality control procedures are used, the remanufactured unit is as good or, in some cases, better than a new engine. Nevertheless, the remanufacturing sector continues to be challenged by the proliferation of engine designs and engine core availability.

THE RIGHT CHOICE

Many shops, tire stores included, have found that replacing worn engines during the slow winter months can boost annual profitability. These shops must choose an engine repair or replacement option that fits their available shop space and technical capabilities. High-end shops might, for example, choose the rebuild option for classic, collectible and antique vehicles while lower-end shops might choose a replacement option for the family grocery-getter. In any case, engine replacement and repair remains a reliable source of income for both shop and jobber alike.















Advertise     Contact Us     Subscribe    
Babcox Media • www.babcox.com
3550 Embassy Parkway, Akron, OH 44333
330-670-1234 • (FAX) 330-670-0874
Babcox Website Counterman: Home