Detroit Diesel 8.2 Liter “Fuel Pincher” V8

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Detroit Diesel Overview, History, Contact Information with Links, etc.
Detroit Diesel 8.2 Overview & History. Shortcomings: Blocks, Pistons, Bottom End, etc.
How To Keep the 8.2 Alive.
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Identifying the 8.2 by Model Number on Options Label.
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Detroit Diesel Corporation (DDC) is an American diesel engine manufacturer headquartered in Detroit, Michigan. It is currently a subsidiary of Daimler Trucks North America, itself a wholly owned subsidiary of the German Daimler AG. The company manufactures heavy-duty engines and chassis components for the on-highway and vocational commercial truck markets. Detroit Diesel has built more than 5 million engines since 1938, more than 1 million of which are still in operation worldwide. Detroit Diesel’s product line includes engines, axles, transmissions, and the Virtual Technician. Detroit engines, transmissions, and axles can be found in several trucks manufactured by Daimler Trucks North America including Freightliner, Western Star, SelecTrucks, Freightliner Custom Chassis and Thomas Built Buses.

See our Detroit Diesel webpage for company Overview, History and Contact Information,
PLUS information about their other products.

Detroit Diesel 8.2

Detroit Diesel 8.2 Liter “Fuel Pincher” marine engine with turbocharger but no charged air cooling.

Detroit Diesel had been building only 2-Stroke Cycle engines like the venerable 6-71 since General Motors created the division in 1938, However, by the late 1970’s with the raising cost of diesel fuel and the inefficiencies inherent in their 2-Stroke Cycle engines which caused them to consume more diesel fuel than their competitors’ modern 4-Stroke Cycle engines, DDC realized that for them to compete in the growing medium duty truck market, they needed a cheap, fuel efficient engine to power medium duty trucks and school buses. They developed a lightweight, slightly under-square (108mm bore x 112mm stroke) 500 cubic inch displacement, 4-Stroke Cycle V8 diesel engine called the 8.2 Liter “Fuel Pincher” which was introduced in trucks and buses for the 1980 model year. Shortly thereafter, the 8.2s became available with turbochargers. Turbocharged models with the highest horsepower ratings were usually charged-air cooled with an intercooler or aftercooler. Eventually, the 8.2 was marinized by Detroit Diesel and a few third-party companies including Covington Diesel, Johnson & Towers. and Stewart & Stevenson. The latter marinized one version with Twin Turbos, but without any charged-air cooling (shown in the picture directly below).

Detroit Diesel 8.2 Liter marinized by Stewart & Stevenson with twin turbos but no charged-air cooling.

The 8.2 engine utilized several design features found in some automotive gasoline engines such as parent bore cylinders and short piston skirts. This in part led to the popular misconception that the 8.2 was an adaptation of an existing gasoline engine. While this is true of some other engines like the ill fated GM 5.7L V8 diesel engine adapted from the Oldsmobile 350ci V8 gasoline engine and the GMC Toro-Flow Diesel engine adapted from the GMC V6-V8-V12 gasoline truck engine family, it is not actually true of the 8.2 which was a new design intended to be a diesel engine from its inception. Unfortunately, due to its misguided design and light build, the 8.2 proved to be quite troublesome especially in marine service as it was prone to “blowing” head gaskets, breaking crankshafts, spinning bearing, etc. as was common with gasoline engines converted into diesel engines. These shortcomings are discussed in detail below. Be sure to read the comments at the end of this page about how GM moved production of the 8.2 from the Detroit Diesel-Allison Division to the Chevrolet-Pontiac-Canada Division when Roger Penske acquired Detroit Diesel from GM because, as it is rumored, “he did not want anything to do with the 8.2”. This production move to an automobile division may have contributed to the belief that the 8.2 was a dieselized gasoline engine. 1990 was the last model year that the 8.2 was offered in any GM products. After 1990, 8.2 engine production slowed to a trickle, ceasing completely by 1994.

Detroit Diesel 8.2 Shortcomings

The 8.2 has several serious shortcomings that makes it a very poor candidate for marine service. These shortcomings include: An “Open Deck” cylinder block with free-standing cylinders and only 10 head bolts per head that results in frequent head gasket failures; Short piston skirts that results in rapid wear of pistons, rings and cylinders; And a weak “bottom end” that results in frequent crankshaft and bearing failures. These are detailed below followed with suggestions on “How to keep the 8.2 alive”.

Detroit Diesel 8.2 Head Gasket Failures

This is the most common 8.2 shortcoming and the results can be catastrophic. The 8.2 head gaskets most often fail between one or more of the combustion chambers in the cylinders and the water jackets that surround the cylinders. This breach allows the engine coolant to enter the cylinder during the intake stroke, then the compressing fresh air to enter the cooling system during the compression stroke, and finally the combustion gases to enter the cooling system during the power stroke and exhaust stroke. Additional engine coolant may enter the cylinder near the end of the exhaust stroke, The catastrophic results of “Hydrolocking” (which can occur when enough non-compressible liquid such as engine coolant has entered the cylinder to stop the piston before top-dead-center) are discussed later in this article.

Detroit Diesel 8.2 Head Gasket.

When the Detroit Diesel 8.2 is compared with other diesel engines, the reasons for the 8.2 head gasket failures become obvious.

Typical diesel engine blocks have cast and machined “decks” that support the top of the cylinders and evenly squash the head gaskets against the heads. In addition, most small V8 diesel engines have at least 6 head bolts (some shared with neighboring cylinders) in a full circle pattern around the top of the cylinder to more evenly provide the necessary head tightness on the head gasket. Both of these features can be seen in the Caterpillar 3208 whose cylinder block shown directly below was produced with 18 head bolts per head and a “full deck” that naturally supports the top of each cylinder, preventing the cylinders from flexing and working against the head gasket, damaging the head gasket.

Caterpillar 3208 “Parent Bore” Cylinder Block with Full “Deck” and 18 Head Bolts per Head.

Unfortunately, the cheaper Detroit Diesel 8.2 engine block, as clearly illustrated in their brochure shown directly below, has neither.

Detroit Diesel 8.2L Block with “Free Standing Cylinders” (Note the open space all around the joined (siamese) cylinders)

This brochure is available for viewing in its entirety by Academy Members as a PDF from our Academy Library – Click Here – where all can see a scathing review of this brochure.

According to the above brochure, the Detroit Diesel 8.2 cylinder block was “designed using computer analysis” (Remember the adage “Garbage in, garbage out”), and was cast without the full head gasket mating surface (the “deck”) leaving the joined “Siamese” cylinders “free-standing”. The 8.2 head gasket mating surface is drastically reduced and consists of just the narrow top ends of the cylinders which consequently can provide only limited sealing surface which has proven to be seriously inadequate.

Detroit Diesel advertised that the reason that they did this was to provide “full length cylinder cooling”, While this design does provide slightly more even cooling of the cylinders, the far more compelling reason to use this design was to leave the top of the cylinder casting open and accessible to allow a more precise locating of the mold (or die) during the casting process which allowed the block to be cast thinner and consequently lighter and cheaper as it did not require as much safety margin thickness for “mold slip”.

This “Open Deck free-standing” cylinder design is not new. Most die cast aluminum blocks are of this design including the ill-fated Chevrolet Vega engine block pictured directly below, which also suffered from frequent head gasket failures at least partly because of this “Open Deck” free-standing design.

Chevrolet Vega Engine Block with “Open Deck” design.

However, to be fair, some of the Vega’s head gasket problems stemmed from the block being cast entirely of aluminum which quickly expands far more then cast iron as it heats up. Since the cylinders ran at a higher temperature then the rest of the block, the cylinders expand more then the sides of the block and thus crush the head gasket against the head while the head is held against the block by the head bolts. And when the cylinders cooled, they would shrink and draw back away from the now crushed head gasket allowing it to leak and blow-out, especially if the engine was later put under heavy load when cold.

Efforts to press iron sleeves or liners into the aluminum Vega blocks has proven fruitless as the aluminum, now thinner and weaker after the boring which was needed to receive the liner, would expand more then the iron liner due to the heat at running temperature, allowing the liners to become loose in the aluminum block. Also, the reduced heat transfer from the liner often resulted in the liner overheating and developing hot spots leading to scoring of the pistons, rings and liner, and spot glazing of the liner.

Aluminum cylinder blocks cast with integral cast iron cylinder liners such as found in most outboard motors (see picture below where the cast-in iron liner can be seen surrounded by cast aluminum), suffer far less expansion then blocks cast entirely of aluminum like the Vega’s block. However when these Iron/aluminum blocks are overheated, the aluminum expands faster then the cast iron liner, often popping the aluminum loose from the cast iron liner making the block unusable due to its reduced ability to transfer heat from the iron liner to the aluminum before before being dissipated into the coolant. It should be noted that outboard motors with free standing cylinders are also prone to suffer blown head gaskets.

Yamaha 40hp outboard motor die cast aluminum cylinder block with integral cast-in iron liners

The Homelite/Bearcat 55hp 4-Cycle cylinder blocks were cast with integral heads eliminating the need for a head gasket. This design required that the pistons be installed and removed from the cylinders through the crankcase. For many years, Mercury Outboard 2-Cycle cylinder blocks were similarly cast with integral heads (shown below with the water jacket cover removed, exposing the top of the integral combustion chamber).

1985 Mercury Inline-6 outboard with water jacket cover removed showing integral cast-in block cylinder head.

In the case of the Detroit Diesel 8.2, besides the drastically reduced head gasket sealing surface and the cylinder expanding and crushing the head gasket, an even more destructive deficiency exists due to the “Open Deck” free-standing design (shown directly below). The cylinders lack any connection between the tops of the cylinders and the engine block. This connection would normally be provided by the “deck” which would support the top of each cylinder and prevent the cylinder from flexing and moving back and forth side-to-side and working against the head gasket when the engine is running especially at higher power output.

Detroit Diesel 8.2 “Open Deck” free standing Cylinders

This process is illustrated in the 4-Stroke Cycle diagram below where the piston can be seen first pushing against the right side of the cylinder during the compression stroke (see first yellow arrow – to the left) and then pushing even harder against the left side of the cylinder during the power stroke (see second yellow arrow – to the right). This pushing force is of course due to the changing angle of the connecting rod to the crankshaft’s rod journal as the crankshaft turns. Without a full “deck” to support the tops of the cylinders, the cylinders are allowed to flex back-and-forth, moved by the side loads induced by the piston, destroying the head gasket. This damage occurs even more quickly when the engine is lugged.

The Detroit Diesel 8.2L Service Manual #6SE421 describes in section 1.1 the procedure for checking the flatness of the top of the block with a straight edge after the head has been removed to determine if the block’s mating surface to the head (the “Firedeck”) is flat enough.

Detroit Diesel 8.2 Cylinder Block Flatness Check

Note that additional transverse locations were required by later revisions to this test procedure.

Checking the Cylinder Block’s “Firedeck” for Longitudinal Flatness Using a Straight Edge.

If the top surface varies by more then .07mm (0.003″) transversely or more then .17mm (0.007″) longitudinally, the block must be “rejected”. When checked, blocks from engines that had blown head gaskets were frequently found to be beyond these limits and therefore could not be reused, relegating them to the scrap heap. Amazingly, the cylinders in these blocks were often found to be slightly bent to one side (as illustrated below), undoubtedly by the force of the pistons during power strokes as illustrated by the yellow arrow above. These bent cylinders were sometimes found to have cracked at their base where they joined the block.

Straight Edge Test of  Transverse Flatness

This “Open Deck free-standing” design makes the 8.2 engine prone to head gasket failures and the resulting internal damage (described later) which tends to be catastrophic. Operation of the 8.2 at flank (full) speed in marine service is not wise unless the propeller is “under-pitched”, allowing the engine to run more easily. This will also be discussed later in this article under “How to keep the 8.2 alive”.

Although GM reportedly considered producing the 8.2 with a “Full Deck” after production was moved to GM’s automotive division in Canada, this apparently never came to fruition.

Parent Bore Cylinders

Most diesel engine blocks are cast and machined to receive replaceable cylinder liners (either dry liners like some of the Ford-Lehman engines or wet liners like the Cummins V-555 V-8 diesel engine and the Cummins C series). The bore of these liners are machined to fit “standard” bore size pistons. If a “Linered” engine suffers excessive liner wear, or damage such as from overheat scoring or rust pitting, the liner is simply replaced. The 8.2’s cylinders, on the other hand, are cast and machined (e.g. bored and honed) directly into the engine block casting to fit “standard” bore size pistons. These are called “parent bore” or “native bore” cylinders.

Most gasoline automobile engines are “parent bore” engines as they are much cheaper to build. This is also the case in a few diesel engines such as the Cat 3208 and the Cummins B series. If a “parent bore” engine block has suffered excessive wear, or cylinder damage such as from overheat scoring or rust pitting, the cylinders can be bored and honed to fit oversized pistons. If the cylinders are too damaged to be bored to receive the largest oversized piston, then the block is replaced or in the case of some engines with thick enough cylinder walls, the blocks can be reused by being bored and sleeved back to standard bore size by pressing in a repair sleeve. The Detroit Diesel 8.2L Service Manual #6SE421 describes in the Shop Notes Section 1.0 (the 78th & 79th pages of the manual) the procedure for installing a repair sleeve in an 8.2 block.

Detroit Diesel 8.2 Repair Liner Installation.

Unfortunately, engine rebuilders that have attempted to use repair sleeves in the 8.2’s cylinder bores have found that when the inherently weak “free standing” cylinder walls are machined oversized for these repair sleeves, the cylinder walls in the block become thinner and weaker, especially at the base of the cylinder where it joins the block, making the 8.2 cylinders more prone to flexing and consequently even more likely to suffer head gasket failure (see next topic below) and in some cases, cylinders cracking at their base. In the past, the best option was to simply replace the cylinder block. Unfortunately, new cylinder blocks are now nearly none existent as Detroit Diesel ceased production of the major castings long ago, and rebuildable used blocks are becoming very scarce. This shortage is compounded by many reusable automotive and marine 8.2 “take-outs” simply being scrapped, as many consider the 8.2 not worth repairing. Occasionally, used 8.2s appear for sale, mostly on the internet, but after close examination they often prove to be too worn or damaged to be used in a rebuild. This all adds to the 8.2’s reputation as a “throw-away” engine.

Sometimes, when twin engines are replaced in a vessel, we find that while one of the engines is in serious trouble, whence the reason for the repower, the other engine may be serviceable or at least salvageable. A proper engine survey and/or a very low price and shipping cost may reduce enough risk that acquiring such an engine may provide a viable solution. Read on to learn more before you leap.

Head Bolts

Also note that the Cummins V-555 and the Caterpillar 3208 each have 18 head bolts per head whereas the Detroit Diesel 8.2 has only 10 head bolts per head. Later model 8.2 head bolts were larger in diameter (15mm vs 14mm) which allowed slightly higher head bolt torque (156 lb-ft vs 145 lb-ft) and thus were supposed to help better hold the heads to the block. It was therefore recommended that all earlier 8.2 engines be retrofitted with the larger head bolts by re-drilling the heads and re-tapping the block. While this may have helped a little, unfortunately this so called “vast improvement” did not come close to solving the inherent weakness of the 10 bolt “Open Deck” free standing cylinder design. In fact, it proved to increase the distortion of the head and block where they mated to the head gasket resulting in even more uneven compression of the head gasket and more crushing of the gasket. The head gasket itself was redesigned and made stronger to compensate which helped a little. Unfortunately, some aftermarket head gaskets are inferior and as a consequence more prone to failure. Fortunately, these weaker head gaskets can usually be discerned by visual comparison to the later, stronger genuine Detroit Diesel gasket. These head gaskets must be both strong and flexible so they can bounce back from being crushed by the expanding cylinders without being broken up by the cylinders working back and forth. Unfortunately, no effective method of stabilizing the cylinders in the block has proven effective such as filling the gap between the cylinders and the block with some type of material or joining them with a welded/brazen pseudo-deck.

The 8.2’s design drastically limits the power that the engine can produce without the head gasket failing and leaking engine coolant into the cylinders, risking hydrolocking the pistons, which often results in bending the connecting rods (as shown below) which will result in later rod bearing failure. Sometimes, the rods are bent enough to break immediately.


Surprisingly, a little water in the cylinder can cause more damage to the engine then a lot of water in the cylinder. This is due to the almost infinite leverage that the crankshaft has against the connecting rod when the piston is near top dead center. The resulting connecting rod damage can be clearly seen in the pictures below.

bent_connecting_rod_1  bent_connecting_rod_2

Additional damage that often goes undiscovered includes twisting of the crankshaft, stretching of the main bearing bolts and caps, and cracking of the main bearing saddles in the block. Shown below is an 8.2 crankshaft that appears to be in good condition, but thorough inspection found it to be slightly twisted and therefore unusable.

Detroit Diesel 8.2 Crankshaft

If the crankshaft slows or stops while the engine is being turned over with the cranking motor, the engine may have just hydrolocked. See our webpage on hydrolocking for the complete description of this malady, its causes and cures.

Detroit Diesel 8.2 Engine Block with Cylinder Head Removed. It Shows Evidence of a “Blown” Head Gasket.

In the case of the particular 8.2 engine pictured directly above with the head removed, the head gasket mating surface flatness test showed the surfaces far beyond the allowed limit because the “free-standing” cylinders had distorted and were bent to one side inside the block. The engine shows evidence of engine coolant leaking past the “blown” head gasket and into the cylinders while the engine was running. “Water Washing” is the term coined by this author to describe the effect that the coolant water has on the surfaces of the combustion chamber (including the top of the pistons) when water (such as from leaking antifreeze) is introduced into the combustion chamber of an engine while it is running. Any carbon buildup on the metal surfaces is literally “steam-cleaned” off, even down to bare metal, by the water in the coolant turning into steam. The “Water Washing” pattern typically originates at the water’s point of entry (such as a head gasket leak) and spreads from there across the combustion chamber surface. This effect can be seen to varying degrees on the tops of the pistons in the 8.2 pictured above, especially the far right piston where shiny metal can be seen on the piston crown.

It is however, nearly impossible for an engine to ingest enough water into the cylinders through a blown head gasket while it is running to hydrolock the engine as most of the water will simply form steam and exit through the exhaust port during the exhaust stroke. However, if engine coolant continues to leak into the cylinder(s) after the engine is shut-down as in the case of the above engine, and then the engine is cranked by the starter motor with coolant in the cylinder(s), hydrolocking of the piston(s) and damage to the connecting rod(s) is more then likely to result. In addition, the crankshaft will likely suffer twisting damage and may break. And the main bearing caps and saddles may suffer stretching and cracking damage from the extremely high loads on the already weak “bottom end”.

Like many other 8.2 engines, hydrolocking made this particular 8.2 engine shown above unrebuildable. Thorough examination should reveal whether or not a block is too damaged to rebuild. Unfortunately, many engines that are so damaged that they are unrebuildable have been rebuilt and have consequently suffered early, if not immediate, failure. Most experienced mechanics consider rebuilding an 8.2 to be unwise and many veteran rebuilders simply refuse to rebuild them.

How Piston Skirt Length Affects Engine Service Life

Some engines have much shorter expected service lives then other engines. There is a direct relationship between the length of the piston skirt and the length of the engine’s service life. The shorter the piston skirt, the greater the wear experienced by the pistons, the rings and the cylinder bores. As shown in the 4-Stroke Cycle diagram above, the piston is forced against the side of the cylinder (yellow arrows) by the angle of the connecting rod to the crankshaft rod journal. Generally, the less lubricated surface that the piston can provide against the cylinder, such as from a shorter piston skirt, the greater the wear will be on the components. Also, the shorter the piston skirt, the greater the tendency for the piston to cock in the cylinder bore resulting in greater uneven wear.

Note the wear and damage to the 8.2 piston, especially between the top ring and the top of the piston pictured in the 8.2 brochure which is shown below left). This brochure claims that “As you can see, these parts remained in like-new condition, showing little or no wear. In fact, they actually miked within new part specifications.” They went on make life projections of several engine components. But do these projections take into account the RATE OF WEAR. The brochure does not make mention of any initial pre-build micrometer measurements. Without these initial measurements, no valid projections can be made. The specifications are a range. If the component was measured to be at one end of the range when first installed and is now found to be at the other end of the range at 3,000 hours, the rate of wear would be considered very high and the life expectancy very low. Unlike the brochure’s claim that “the piston itself is projected to live 30,000 hours.” the fact is that the shown piston (at 3,000 hours) is so badly worn and damaged that it is no longer usable especially due to metal transfer, scuffing and scoring. This is also true of the piston rings, connecting rod bearings crankshaft main bearings and several other components clearly shown in the brochure. It is doubtful that any competent mechanic would reassemble this engine with any of these badly worn/damaged components.

Longer life engines typically have piston skirts at least as long as the cylinder bore diameter. Compare the length of the short-lifed 8.2 piston skirt shown below left with the long-lifed Caterpillar 7N4515 piston skirt shown below center.

Short-Lifed 8.2                             Long-Lifed Cat

One exception to this rule is the super-long-lifed Crosshead engine which needs little piston skirt because the top of the connecting rod is not attached directly to the piston.  The top of the connecting rod attaches to a “crosshead” which rides in guide channels.  A long piston rod then connects the crosshead to the piston. The lubricated crosshead carries the side-loads instead of the piston (see Crosshead engine below). Some crosshead engines have a life expectancy of well over 100 years running 24/7 before rebuild is required. Some of these engines have already exceeded 3 million hours without a teardown. They are becoming more commonplace in large cargo ships where they are some of the most powerful engines in the world.

Sulzer Crosshead Diesel Engine

Another  engine that has achieved near-zero piston side loads and therefore extremely long life is the Beam engine. The common term for this “teeter-totter” feature is a “Walking Beam”. It was incorporated in many early steam engines especially those used for marine propulsion. A familiar application of a walking beam is on oil well pumpjacks.

Also compare the distance from the crown of the piston to the first compression ring on the 8.2 piston to that of the Caterpillar piston (shown two pictures above). The distance is much less on the 8.2 piston which makes the piston and rings more vulnerable to damage from engine overheating, thermal runaway, and detonation then the Caterpillar piston.

Also note how the actual contact surface of the 8.2 piston skirt has been further reduced by being squared-off around the wrist pin boss to make the piston lighter. The skirt is also cut-away to provide clearance for the rotating crankshaft when the piston is near bottom-dead-center (BDC) which allows for a shorter connecting rod. The 8.2 was designed with shorter, cut-away piston skirts and shorter connecting rods so the cylinders could be shorter and thus the engine’s overall height could be less, allowing it to fit into more limited-height applications. This also made the engine lighter and cheaper to build. As a consequence the 8.2 has a much shorter expected service life then other engines with longer piston skirts. However, because of the 8.2’s other shortcomings, the 8.2 rarely survives long enough to actually “wear out”.

Detroit Diesel 8.2 Crankshaft and Bearing Failures

The 8.2 engine below has “thrown” the #4 connecting rod through the cylinder block and oil pan near the surfaces where they join, punching holes in both. In this case, “Hydrolocking” damage to the inherently “weak bottom end” due to a coolant leak into a cylinder from a blown head gasket as discussed earlier was determined to be the cause for this failure.

Detroit Diesel 8.2 with #4 rod thrown thru the crankcase and the oil pan which has been removed.

Unfortunately, the 8.2 also suffers from a “weak bottom end”. Reports of “broken cranks”, “spun bearings” and “thrown rods” NOT caused by “Hydrolocking” are far too frequent. This weakness, however is common of most smaller “V” cylinder configuration engines, especially those with cylinder bores less then 5 inches (127mm) and is due to the overall shortness of the crankshaft. With twice as many pistons connected to a V8 crankshaft which is rarely longer then an inline 4-cylinder crankshaft of the same bore, there just isn’t much room for the connecting rod bearings, the crankshaft main bearings, and the crank webs. Note how narrow the crank webs, main bearings and connecting rod bearings have to be to fit on the short 8.2 crankshaft  shown below. The #2, #4, #6 and #8 pistons and connecting rods have been removed and the narrowness of the rod bearings can be clearly seen.

Detroit Diesel 8.2 Crankcase

Unfortunately, in the case of slip-bearings commonly used in 4-Stroke Cycle engines including the 8.2 crankshaft bearings, the narrower the bearings, the more difficult it is maintain an adequate lubricating oil film between the crankshaft’s steel surface and the softer metal surface of the bearing shell as the oil is more quickly squeezed out of the narrower bearings by the heavy loads of a high compression diesel engine especially at higher RPM’s. Without the oil film to keep the two metal surfaces of the bearing separated, they will make contact with each other and score the surfaces, making bearing failure imminent. This damage can be clearly seen on the bearing shell shown below that was removed from the engine above. The lead based overlay has been abraded enough to start exposing the copper based underlay which makes failure of this bearing eminent.

Detroit Diesel 8.2 Bearing – Damaged

Even though the connecting rod pins on a V8 crank are the widest journals on the crank, when assembled the V8 crank will have two connecting rods crowded onto each rod journal leaving little room for each individual rod bearing.

V8 Crankshaft with Two Rods assembled to each rod Journal.

In the picture third above and the illustration below, it is easy to see how narrow the rod bearings of an 8.2 have to be. Note the two oil feed holes per rod journal (one for each connecting rod. In a fully pressurized lubrication system like the 8.2 has, the oil is fed to the center of each bearing so that it can form an oil film between the crankshaft journal and the bearing surfaces, as it works its way to the outer edges of the bearing where it squirts out and splatters around the crankcase as the crankshaft turns. Oil tends to exit narrow bearings much more quickly. The wider the bearings, the more oil they can hold longer between the metal surfaces of the crankshaft and bearings, hence wide bearings can carry higher loads.

Detroit Diesel 8.2 Crankshaft – Illustration.

The larger the cylinder bores, the longer the crankshaft and therefore the more room available for wider bearings. “V” Pattern engines such as V8 engines with cylinder bores larger then 6″ typically have plenty of room on the longer crankshaft for bearings wide enough and crank webs strong enough to allow the engine to produce very high output, even well over one horsepower per cubic inch of displacement.

Unfortunetely, for the 8.2 the typical crankshaft wear is far greater then the wear found on better engines. The Detroit Diesel 8.2 Service Manual 1985 contains the recommended procedure (see Section 1.3 Crankshaft) for resurfacing “typical Ridging of Crankshaft” as much as .025mm (0.001″) using emery cloth and then crocus cloth. This rather crude Do-it-yourself procedure can easily result in very poor bearing journal surfaces that can cause early bearing failure. A qualified crankshaft machinist with the proper equipment able to perform quality resurfacing has the best chance of providing a satisfactory bearing journal surface.

On the 8.2 crankshaft pictured four above and then illustration directly above, note how narrow the five main bearing journals are especially when compared with the 4-cylinder crankshaft below. Crankshaft main bearings will be discussed in more detail a little later.

Another issue with any small V8 crankshaft is the narrow crank webs which are much weaker and consequently much more prone to breakage as shown below.

V8 Crankshaft with broken web near front end of crankshaft (left).

By comparison, the inline 4-cylinder crankshaft below which will have only one rod fitted per journal when assembled will have much wider rod bearings. Note the much wider main bearing journals which will accommodate much wider main bearings. Also note the wider and much stronger crank webs between the bearing journals.

Detroit Diesel 4-53 4-cylinder 2-Stroke Cycle crankshaft.

The inline 4-cylinder crankshaft shown above has 5 main bearings. The crank webs, and the width and diameter of the main and rod bearings have been optimized to carry the stress and load of a high compression, high output engine. By comparison, the V8 crankshaft has the same number of main bearings for twice as many cylinders, and the V8 main bearing journals are much narrower. You can see how crowded a small V8 crankcase can be in the picture directly below. There just isn’t enough room for rod bearings or main bearings to be wide enough to carry the heavy loads generated by a high speed, high compression, high output engine.

Notice that the main bearing journals of the V8 crankshafts shown in the illustration and pictures above have been increased in diameter to increase the bearing surface in an effort to compensate for their narrowness. But at some point this becomes counter-productive because the increased diameter increases the slip-bearing surface speed which makes it more difficult for the oil to maintain adequate oil film thickness at higher RPM’s. By comparison, a 4-cylinder crank’s main bearings can be wider so they can more easily maintain oil film thickness and carry the loads, hence the journals can be smaller in diameter to reduce bearing surface speed. This is why inline engines with the wider bearings and stronger crank webs, and main bearings between each cylinder can be air charged (e.g. with a turbocharger) to reliably produce more than twice the horsepower per unit of displacement then a small V8 like the 8.2. Air-charging these stronger inline diesel engines can also enable them to run cleaner with fewer emissions.

Engines with longer piston strokes have the advantage of typically producing much higher torque at slower crankshaft speeds (RPMs). The 8.2 was designed with a stroke much shorter then most other diesel engines of this displacement. It is just slightly “under-square” with a 108mm bore x 112mm stroke. Besides allowing the engine height to be lower, the shorter stroke also has the advantage of reducing the load on the crankshaft bearings, however the load on the rod bearings is higher. Unfortunately, any of these short stroke, nearly-square and over-square engines produce less torque and have to be set-up to run at higher RPM’s to produce their maximum power, which is limited by their increased crankshaft slip-bearing surface speeds. Unfortunately, as bearing surface speed increases, bearing wear increases and so does the risk of bearing failure, especially in the case of the narrow bearings used in the 8.2.

In conclusion

The above comparisons show why smaller V8 engines that lack the space for the wider crankshaft bearings and stronger crank webs are not capable of the higher power outputs of comparable displacement inline engines. These are some of the main reasons why most diesel engine manufacturers have abandoned building small V8 engines and have embraced inline configurations especially the turbocharged 6 cylinder inline with 7 main bearings such as the Cummins B and C series engines. In the case of V8 engines with bores larger than 5 inches (127mm), they are longer and therefore have more room for wider crankshaft bearings and stronger crank webs which means that they can have much stronger “bottom ends” and therefore higher power outputs  per displacement unit then their smaller, shorter, and weaker little brothers.

Other 8.2 issues

Tuning-up the engine, especially adjusting the injectors, is complex, time consuming, and requires special tools which are becoming more and more scarce. One such tool is the Timing Pin and Guide Tool # J 29139 illustrated on SEC 14.2.1 page 1 of the Detroit Diesel 8.2L Service Manual #6SE421. This manual is available to current Academy members for viewing from our Academy Library. The complete procedure is described in that section (14) of the manual including the special tools required. Several of these tools are no longer available from Detroit Diesel, but can be fabricated. It would be more convenient to find someone knowledgeable and experienced in the procedure who already has the proper tools, but this is proving more difficult with each passing day. The above service manual also contains sections on Preventive Maintenance and Trouble Shooting that can be very helpful.

Quality replacement parts are becoming scarce and more expensive. New major parts (ie blocks, heads, crankshafts, etc.) are practically non-existent and usable used parts are also becoming scarce.

How to keep the 8.2 alive

Because of these recognized inherent weaknesses, Detroit Diesel never did set up the 8.2 engines to produce very high power outputs (see Engine Specifications Table later in this article). Fortunately, in a vehicular application, the engine is rarely operated at higher speed and power output for very long, usually just during acceleration and when climbing hills. If the 8.2 engine is intentionally operated at reduced power (below 80%), by shifting down and easing up on the throttle, doing so has proven to help it survive. In a marine application this is accomplished by under-pitching the propeller, avoiding any rapid acceleration, and if necessary, reducing the vessel’s cruising speed. Unfortunately, this will lower combustion gas temperatures (below 800ºF) that encourages excessive carbon buildup and its ensuing problems, including “injector misfire” and detonation. Since the practice of routinely running at full throttle (flank speed) to blow out the carbon soot is NOT recommended with the 8.2, because doing so often results in head gasket failure or catastrophic bearing failure, other ways of reducing carbon buildup must be utilized. Unfortunately, the benefits of “water injection” are limited because the 8.2 should not be run at full throttle when most of the soot would be “steam-cleaned” and blown out. But adding fuel additives that help keep fuel injectors clean and reduce carbon buildup can be quite helpful.

Like many 4-Stroke Cycle engines, the 8.2 will tend to detonate when started in colder weather. Detonation is the phenomenon when the heated gases from combustion expand in the combustion chamber faster then the speed of sound and generate a supersonic shockwave. Detonation in a cold engine is the result of the increased ignition lag-time that unfortunately, delays ignition until the combustion chamber has an overabundance of fuel. once ignited, the large quantity of fuel burns too fast, generating a shockwave. This shockwave or “sonic boom” if you like, can be heard by the naked ear as the characteristic “knock” or “ping” of detonation depending on the frequency of the sound, the “ping” being the higher frequency. Typically, the larger the cylinder, the lower the frequency. When detonation occurs in the 8.2, which mechanically injects the diesel fuel directly into the relatively fragile cylinder instead of into a heavily reinforced precombustion chamber, the shockwave too often causes damage to the already “weak” head gaskets because they are directly exposed to the shockwave. Starting any diesel engine, but especially an 8.2 in cold temperatures is greatly improved by fitting an engine warming device such as a block heater or an intake air heater. Heating the incoming air reduces the ignition lag-time, avoiding detonation.

It is never a good idea to use “Ether” to start an 8.2 as it will often detonate in the cylinders  causing head gasket damage or worse. Detroit Diesel made the mistake of providing a cold weather starting fluid injection canister as an option on the automotive and industrial versions of the 8.2, like they had offered on their 2-Stroke Cycle engines which were not prone to detonation, giving the impression that spraying starting fluid into the 8.2 was acceptable. Of course it proved to be detrimental and many 8.2 engines have been seriously damaged as a result. The starting fluid device was never offered for the marine version of the 8.2 because having such a volatile fuel as starting fluid in the engine space of a vessel, especially a diesel fueled one, is extremely dangerous. Remember that electrical devices such as relays, generators, alternators and starter motors on diesel engines in most vessels are not required to be ignition protected and therefore can provide an ignition source like a spark for volatile fuels such as gasoline, ether, LPG, etc. Instead, it is better to fit an engine warming device such as a block heater (which is usually AC powered) or an intake air heater (which is usually DC and can be powered by the ship’s batteries) if the temperature is too cold for the engine to start easily.

Pay particular attention to the engine’s cooling system, especially the raw water pickup and sea strainer. Keep them clear of any obstructions. Also keep the raw water pump impeller, the heat exchanger, the engine coolant (antifreeze), the pressure cap, all hoses, and the engine belts and pulleys in good shape. The exhaust mixing elbows on wet exhaust systems should be routinely checked for deterioration and clogging. Due to the poor design detailed above regarding head gasket failures, even the slightest overheating can result in serious consequences. Consider retrofitting the engine with the larger head bolts and later, stronger head gaskets.

Fluid analysis of the engine coolant and engine oil can help detect a leaking head gasket and can also help determine the extent of other internal damage.

It may also prove helpful to pull the fuel injectors and inspect the cylinders with a borescope for internal engine damage, and “water washing”, which is evidence of a “blown” head gasket.

If you replace injectors BEWARE. The injector markings may NOT indicate that the injectors have been drilled larger for the greater fuel delivery required by the higher rated engines. This can result in some or all of the injectors delivering too little fuel for the higher rated engines or too much fuel for the lower rated engines. Ensure that the injectors’ fuel discharge holes, valves , etc. are the proper size for the rated horsepower of the engine. And yes, this injector mismatch may have already happened to your engine sometime in the past.

Ensure that the engine oil is properly maintained. Always use a quality Diesel Engine Lubricating Oil such as DELO 400. See our webpage on engine oil. Always shake or stir the new oil container to mix the new oil before pouring the new oil into the engine as the oil and additives tend to separate over time. This is especially true of larger containers of oil such as drums which must be stirred routinely to mix the heavier additives like zinc that have settle to the bottom of the drum. Always maintain the proper oil level in the engine. Always replace the oil filter during every oil change. Then cut open the old filter and check it for metal. See our webpage on Inspecting oil filters for metal. Always use a quality oil filter. Consider fitting the engine with a by-pass oil filter in addition to the original full-flow oil filter. The small micron by-pass filter’s element can remove much smaller contaminate particles from the oil then the larger micron full-flow filter’s element can, thus reducing wear from oil contaminates. The 8.2’s narrow crankshaft bearings make them more susceptible to wear from these smaller particles in the oil.

Lastly, let’s consider one more source of wear and failure. If the engine sits dormant for long periods, consider fitting a pre-oiler to the engine to pressurize the oil galleys and fill the bearings before starting the engine. This practice reduces wear considerably during startup, especially in the case of the narrow 8.2 crankshaft bearings. Pre-oilers are often fitted to commercial engines to reduce startup wear. Sea our webpage on Pre-oilers.

A number of vessels are fitted with 8.2s for propulsion. Many of these engines are already in trouble, and some of the owners don’t know it, but some do. There is no denying that the 8.2’s problems haven’t adversely effected the value of the vessels which are equipped with them. Whether you own such a vessel already or are considering buying one, a good place to start is with a fluid analysis of a properly drawn sample of the engine oil. Even when you don’t have any previous sampling results to trend from, a single current sampling can still reveal if any of the shortcomings inherent in the 8.2 have already resulted in damage to the engine and often to just what extent. Academy members have the opportunity to submit oil analysis reports to our engine experts (at no charge) for their opinion as part of our “Ask-On-Expert” Program.

If the 8.2 is currently in good condition, and your plan is to keep the engine for awhile, the best advise is to make the above improvements, keep it maintained, and run it easy. If you intend on keeping the vessel for a while, you should probably start budgeting for a repower. But remember that tight quarters may limit your choice of replacement engines.

What others have said about the 8.2

FROM Genesis: “The DD 8.2s are in fact diesels, and have the unit injector system that Detroits are known for, but they’re 4 strokes. They were also called “fuel pinchers”, although they were never really all that good at extracting the higher-BSFC numbers we now get from electronics. They’re parent-bore engines and have an “open deck” block design, which means that they’re prone to head gasket problems. Early year engines also had too small of head bolts for proper sealing pressures. I am generally a Detroit fan, but this is the one engine of theirs I would not own.”

FROM Scrod: “Detroit Diesel 8.2 Liter, head gasket failures (no block deck to support the liners, you’d think they would have learned from the Cadillac 4100) and bottom end problems. It doesn’t live up to the “Detroit Diesel” legend. I would avoid it.”

FROM Mobil_Bob: “8.2 Detroit…you couldn’t give me one even if you papered it with 20 dollar bills! Cam bushings were not presized. If you replace them the engine had to have the cam bores align bored. Oil pump gearrotor bushing. Replace it and you have to mount the engine block in a Bridgeport to resize the bushing so the outer gear will fit, 15mm head studs, that later had to be drilled out in situ?? tapped to 17mm, what a joke! Monobloc free standing cylinders much like that … of an engine that cadillac had hell with. Reset the overhead, injector and racks??? baseline method using dial indicators??? insane!!”

Johnson & Towers Marinized Detroit Diesel 8.2L 4-Stroke Cycle V8 Diesel Engine with Turbo & Intercooler.

Similar Engines from Major Competitors

Detroit Diesel has never produced any other engine to fill this medium duty truck market. Similar engines were produced by other leading diesel engine manufacturers to compete in this growing market. Cummins developed the 555 cubic inch displacement V-555 “Triple Nickel” engine, but like the 8.2, it proved to have a weak “bottom end” as well as other fatal problems. Eventually, Cummins settled on the “B” and “C” series engines such as the inline six cylinder 5.9 liter and 8.3 liter engines to fill this niche which they did quite successfully.

Caterpillar had come out with the 1100 medium truck engine in the 1960’s which became the 3160 marine engine. It was a larger bore V8 engine at 636 cubic inches of displacement, which made it a longer engine with a longer crankshaft and therefore more room for wider crankshaft bearings. It still suffered from a weak “bottom end” like it’s other V8 rivals. but not near as much. However, in marine use it also suffered from a design flaw of the interference fit camshaft driven gear that sometimes resulted in the gear spinning on the camshaft during a “prop-strike” or a “hard shift” which would in turn result in catastrophic internal damage to the engine. When Caterpillar came out with the 3160’s successor, the 3208, they strove to strengthen the “bottom end” which they succeeded in only slightly improving, but they did nothing to remedy the camshaft gear weakness. There is however a fix for this weakness that involves drilling the gear and camshaft for countersunk fasteners.

Like most other engine manufacturers, Caterpillar eventually abandoned the small V8 configuration and turned to inline six cylinder engines such as the 3126. It also may be important to note that none of the small V8 diesel engines, especially those used by Ford and Chevy in their pickup trucks, etc. have successfully transitioned to marine service.

Identifying the 8.2 by Model Number on Options Label

The options and equipment for the 8.2 engines can be identified by the Option Label that includes the engine serial number and model number. Engines prior to serial number 8G27987 were built with standard equipment only. No optional equipment was offered and no model label was provided. Engines after serial number 8G27987 will have the Option Label located behind the water pump.

A typical Model Number would be RC 4087-7300. This Model Number is broken down below to demonstrate the identification on the engine.

Specifications of Detroit Diesel 8.2L 4-Stroke Cycle
Automotive, Industrial and Marine Engines
Features: Horizontal Crankshaft & Parent Bore Cylinders

^ Data:
= Data Not Available from Data Source. ¿… = …? = Data in Question/Unconfirmed.
Manufacturer/Vendor & Model of Base Engine followed by Specifications.

^ CYL: Cylinder Configuration – (Dash w/no spaces) Number of Cylinders: (example: “V-8”)
^ ^ Cylinder Configuration: …V = V Pattern (eg V-8).
^ BORE & STROKE: …mm = Millimeters. …in = …” = Inches.
^ DISPLACEMENT = Swept Volume: …cc = Cubic Centimeters (cm³). …L = Liters. …ci = Cubic Inches (in³).

MODEL RATINGS: Base Engine Model, Duty Ratings, Power Ratings, etc.
^ Also Engine Ratings from Engine Marinizers and Manufacturers & Vendors of Marinizing Components.
^ A-F: Aspiration-Fueling: Intake Air uncharged or charged – Petrol or Diesel Fueling.
^ ^ Aspiration: N = Naturally Aspirated (uncharged). T = Turbocharged. TT = TwinTurbo. …i = Intercooled.
^ ^ Diesel Fueling: M = Mechanical Injection. …i =  Integral Injector.
^ DR = Duty Ratings: See the Engine Duty Ratings at the end of the Table.
= Multiple Ratings Available.
^ POWER: kW = Kilowatts. HP = Horsepower. BHP = Brake Horsepower. MHP = Metric Horsepower.
^ RPM = Power Ratings @ Revolutions Per Minute.
^ YEARS: Beginning-Ending. Trailing “–” (Dash) without an Ending Date = Still in Production/Available.
^ ^ Vendors usually market products after production ceases, often until stockpiles are exhausted.
^ DS = Data Source: Click DS Link to view DS. ⊕ = Data Compiled from Multiple Sources.

Clicking a Model Link in the table will open a new window displaying our webpage containing details about that model. Clicking a Vendor Link will open a new window displaying our webpage containing details about that vendor and their products.

8.2 V-8 108mm / 4.25in 112mm / 4.41in 8.2L / 500ci
8.2N (w/4A40 Inj) N-Mi CON 97 130 2800 1979-1991 ?
8.2N (w/4A40 Inj) N-Mi CON 97 130 2800 1979?-1991? Db1
8.2N (w/4A40 Inj) N-Mi 130 2800 1982-1985 Dm1
8.2N (w/4A53 Inj) N-Mi CON 97 130 2800 1979?-1991? Db1
8.2N (w/4A53 Inj) N-Mi CON 97 130 2800 1979-1991 ?
8.2N (4083-7100) N-Mi MIN 97 130 2800 1988? Ds2
8.2N N-Mi 108 145 2600 1979-1991 ?
8.2N (4083-7100) N-Mi CON 108 145 2800 1988? Ds2
8.2N (4087-7100) N-Mi 108 145 2600 1988? Ds1
8.2N (w/4B45 Inj) N-Mi 145 2800 1984-1985 Dm1
8.2NC (w/4B45 Inj) N-Mi 145 2800 1984-1985 Dm1
8.2N N-Mi 112 150 2800 1979-1991 ?
8.2N (4087-7100) N-Mi 112 150 2800 1988? Ds1
8.2N (w/4A53 Inj) N-Mi INT 119 160 2800 1979?-1991? Db1
8.2N (w/4A53 Inj) N-Mi INT 119 160 2800 1979-1991 ?
8.2N (Marine) N-Mi CON 119 160 2800? 1979-1991 ?
8.2N (w/4A53 Inj) N-Mi 160 2800 1982-1983 Dm1
8.2NC (w/4A53 Inj) N-Mi 160 2800 1982 Dm1
8.2N (w/4A53 Inj) N-Mi 165 2800 1984-1985 Dm1
8.2N (w/4A53 Inj) N-Mi 165 3000 1981-1983 Dm1
8.2NC (w/4A53 Inj) N-Mi 165 3000 1981-1983 Dm1
8.2NC (w/4B55 Inj) N-Mi 165 2800 1984-1985 Dm1
8.2N N-M 127 170 2600 1979-1991 ?
8.2N (4087-7100) N-Mi 127 170 2600 1988? Ds1
8.2T (w/4A53 Inj) T-Mi 156 2600 1983 Dm1
8.2T (w/4A53 Inj) T-Mi 160 2600 1984 Dm1
8.2T (w/4A53 Inj) T-Mi CON 119 160 2800 1979?-1991? Db1
8.2T (w/4A53 Inj) T-Mi 160 2800 1982-1983 Dm1
8.2T (w/4A65 Inj) T-Mi CON 119 160 2800 1979?-1991? Db1
8.2T (w/4C65 Inj) T-Mi 160 2800 1983 Dm1
8.2T (w/4A53 Inj) T-Mi 165 2800 1984-1985 Dm1
8.2T (w/4J60 Inj) T-Mi 165 2600 1985 Dm1
8.2TC (w/4K60 Inj) T-Mi 165 2600 1985 Dm1
8.2T T-Mi 134 180 2800 1979?-1991 ?
8.2T (4087-7300) T-Mi 134 180 2800 1988? Ds1
8.2T (w/4H60 Inj) T-Mi 190 2800 1985 Dm1
8.2T (w/4A65 Inj) T-Mi INT 149 200 2800 1979?-1991? Db1
8.2T (w/4A65 Inj) T-Mi INT 149 200 2800 1979-1991 ?
8.2TC (w/4E67 Inj) T-Mi 200 2800 1984-1985 Dm1
8.2T (Marine) T-Mi CON 149 200 2800 1979?-1991 ?
8.2T (w/4C65 Inj) T-Mi 205 3000 1981-1983 Dm1
8.2T (w/4C65 Inj) T-Mi 205 2800 1984-1985 Dm1
8.2T T-Mi 157 210 2800 1979?-1991 ?
8.2T (4087-7300) T-Mi 157 210 2800 1988? Ds1
8.2T (4082-8300 4A70)* T-Mi 160.4 215 3200 1983 Ds3
8.2T (4082-8301 4A70)* T-Mi 160.4 215 3200 1983 Ds3
8.2T (Calif) T-Mi 168 225 2800 1979?-1991 ?
8.2T (4087-7300 Calif) T-Mi 168 225 2800 1983? Ds1
8.2T T-Mi 172 230 2800 1979?-1991 ?
8.2T (4087-7300) T-Mi 172 230 2800 1988? Ds1
8.2T (4083-7336) T-Mi MAX 172 230 2800 1988? Ds2
8.2T (w/4B75 Inj) T-Mi 230 2800 1985 Dm1
8.2T T-Mi 250 3000? ⊗-⊗ ?
8.2TI? Ti-Mi 300 3200? ⊗-⊗ ?
8.2T T-Mi 250 3000? ⊗-⊗
8.2TI? Ti-Mi 300 3200? ⊗-⊗
8.2TT? TT-Mi 300? 3200? ⊗-⊗
8.2T T-Mi 250 3000? ⊗-⊗
8.2TI? Ti-Mi 300 3200? ⊗-⊗
8.2T T-Mi 250 3000? ⊗-⊗
8.2TI? Ti-Mi 300 3200? ⊗-⊗
8.2TT? TT-Mi 300? 3200? ⊗-⊗
NOTES: All models have “Parent Bore” type cylinder blocks. Repair sleeves are NOT recommended for high load applications such as marine propulsion. Stewart & Stevenson marinized a Twin-Turbo version, with no cooler (see picture far above)
*Marine Rated Model.

Detroit Diesel
Engine Duty Ratings

CON = Continuous
INT = Intermittent
MIN = Minimum
MAX = Maximum
Gross = Gross Power

CON = Continuous

INT = Intermittent
MIN = Minimum
MAX = Maximum

CON = Continuous

INT = Intermittent
PC = Pleasurecraft

Covington Diesel
Engine Duty Ratings

CON = Continuous

INT = Intermittent
PC = Pleasurecraft

Johnson & Towers
Engine Duty Ratings

CON = Continuous
INT = Intermittent
PC = Pleasurecraft

Stewart & Stevenson
Engine Duty Ratings

CON = Continuous
INT = Intermittent
PC = Pleasurecraft

Detroit Diesel 8.2L Engine Serial Number Guide
Serial Number Suffix = 8G
Total Engines Built = 300,000±

Year MFR'd Starting Serial # Approximate Number of 8.2L Engines Manufactured
1979 870 1‚510 (Full production started near the end of 1979)
1980 2380 23‚934 (including ? spares)
1981 26314 23‚307 (including ? spares)
1982 49621 18‚105 (including ? spares)
1983 67726 22‚822 (including ? spares)
1984 90548 25‚097 (including ? spares)
1985 115645 30‚000 (including 5‚000 spares)
1986 145645 24‚274 (including ? spares)
1987 169919 24‚475 (including ? spares)
1988 194394 20‚163 (including ? spares)
1989 214557 16‚256 (including ? spares)
1990 230813 69‚197 (including 50‚000 spares)
1991 300010 124 (including ? spares)
1992 300134 135 (including ? spares)
1993 300269 ? (including ? spares)
NOTES: Suffix = 8G From Detroit Diesel Engine Serial Number Guides D#1‚ Dp#1‚ S#1.

The very high number of spares produced is indicative of the high failure rate of this engine.

Product Documentation

Documentation with Bold Titles are part of our Academy Library!
To view the entire document, click on its Bold Title Link to go to our webpage for
that item and then scroll down to the "Academy Library" section on that page.
DS = Data Source for Engine Specifications.

Catalogs & Brochures: ↓c/b↓
Detroit Diesel Brochure – 8.2L Advantages Db1
SpecSheets: (Specification Sheets‚ Data Sheets‚ FactSheets) ↓s↓
Detroit Diesel SpecSheet – 8.2L Automotive Engine Ds1
Detroit Diesel SpecSheet – 8.2L Industrial Engine Ds2
Detroit Diesel SpecSheet – 8.2L Marine Engine Ds3
Charts and Graphs: ↓g↓
Detroit Diesel Chart/Graph – 8.2 (Notes) Dg?
Pictures: ↓x↓
Detroit Diesel Picture (View) – 8.2 (Notes) Dx?
Press Releases: (by Date: = YYMMDD) ↓pr↓
Detroit Diesel Press Release (DATE) – 8.2 (Notes) Dpr?
Model History: ↓MH↓
Detroit Diesel Model History – 8.2 (Notes) Dh?
Serial Number Guide: (Manufacture Date Code Identification) ↓#↓
Detroit Diesel Engine Serial Number Guide #6SE266 D#1
Detroit Diesel Engine Serial # GuideDepco Power Systems Dp#1
Detroit Diesel Engine Serial Number GuideSwift Equipment Solutions S#3
Installation Instructions: ↓i↓
Detroit Diesel Installation Instructions – 8.2 (Notes) Di?
Installation Drawings with Dimensions: ↓d↓
Detroit Diesel Drawings w/Dims – 8.2T (4082-8300) Dd1
Detroit Diesel Drawings w/Dims – 8.2T (4082-8301) Dd2
Detroit Diesel Drawings w/Dims – 8.2T (4083-7366) Dd3
Detroit Diesel Drawings w/Dims – 8.2T (4087-7336) Dd4
OpManuals: (Owner's/Operator's Handbooks/Guides/Manuals) ↓o↓
Detroit Diesel OpManual – 8.2 (Notes) Do1
Parts Catalogs: (with Exploded Views & Parts Lists) ↓p↓
Detroit Diesel Parts Catalog – 8.2L #6SP152 Dp1
Parts Bulletins: (by Date: YYMMDD) ↓pb↓
Detroit Diesel Parts Bulletin – 8.2 (Notes) Dpb?
Shop Manuals: (Repair/Service/Technical/Workshop Manuals) ↓m↓
Detroit Diesel Service Manual – 8.2L #6SE421 Dm1
Wiring Diagrams: ↓w↓
Detroit Diesel Wiring Diagram – 8.2 (Notes) Dw?
Service Bulletins: (by Date: YYMMDD) ↓sb↓
Detroit Diesel Service Bulletin (DATE) – 8.2 (Notes) Dsb?
Product Recalls: ↓r↓
Detroit Diesel Recall – 8.2 (Notes) Dr
Related Documentation: ↓rd↓
Detroit Diesel ? – 8.2 (Notes) Drd?

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Forum Posts, Tech Notes & Tech Tips

Forum Posts:
Detroit 8.2L‚ Good and Bad — The Diesel Garage
Would you buy a big truck with an 8.2L Detroit Diesel — The Diesel Stop
Detroit Diesel 8.2 liter — Sam's Marine
6.5 or 8.2 — The Truck Stop
Detroit Diesel 8.2L Engines — UnifliteWorld
1994 Detroit Diesel 8.2L – The Hull Truth
Tech Notes:
Tech Tips:

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"The" & "A/An" have been moved to the end of the title.

8.2 Detroit Diesel Engines — Steve Johnson at eHow
Detroit Diesel 8.2L NA Truck Engine Test Run — YouTube
Detroit Diesel 8.2L Turbo Marine Engine Test Run — YouTube
Detroit Diesel 8.2L NA (DT8 2LEC-7510460GN) Test Run — YouTube
Detroit Diesel — DDC
Detroit Diesel — Wikipedia
Barrington Diesel Club
8.2 Detroit Diesel Fuel PincherFacebook.

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2.6 – Boat Equipment (Vendors, Specs, Manuals, Reviews, Recalls,+).
2.6.8 – Propulsion Machinery (Types, Configurations, Features, Control Systems,+). – Engine Brands & Manufacturers (Petrol/Gasoline, Diesel, CNG, A~Z,+). – Engine-to-Marine Gear Interfaces (SAE Specs, Damper Plates, Jackshafts,+). – Marine Gears (Inboards, V-Drives, IOs, OBs, Surface-Piercing,+). – Shafting (Propshafts, Couplings, Seals, Bearings, Struts, Keys, Nuts,+). – Propellers (Screws, Water Jets, Paddle wheels,+).
2.6.9 – Electrical Systems (Direct Current, Alternating Current,+). – Auxiliary Generators.

15.1 – Refitters & Repairers by Regions (Shipyards, Boatyards, Riggers, Repair Shops,+).
15.1.1 – Refitters & Repairers – United States.
15.2 – Boat Repair Schools (Hull, Systems, On-Board Equipment, Propulsion Machinery,+).
15.3 – Do-It-Yourself Refitting & Repair (Installation, Maint, Troubleshooting, Repair,+).
15.3.1 – DIY: Fundamentals. – DIY: Tools, Usage, Safety,+. – DIY: Rot, Corrosion, Fatigue,+. – DIY: Troubleshooting, Failure Analysis,+.
15.3.2 – DIY: Vessel Structure. – DIY: Steering & Thrusters (Mechanical, Hydraulic,+). – DIY: Galvanic Corrosion Protection. – DIY: Hull Penetrations & Openings (Thru-Hulls, Scuttles, Skylights, Hatches,+).
15.3.3 – DIY: Propulsion Machinery (Control Systems,+). – DIY: Engines (Fuels, Troubleshooting, Repair, Rebuilding vs Repowering,+). – DIY: Engine Mechanical (Pistons, Rods, Crankshafts, Blocks, Heads, Valves,+). – DIY: Engine Lubrication (Splash, Forced, Oil, Filtration, Additives, Oil Analysis,+). – DIY: Engine Fuel (Petrol/Gasoline, Diesel, CNG,+). – DIY: Engine Electrical (Starting, Charging, Instrumentation,+). – DIY: Engine Cooling (Air, Raw Water, Fresh Water,+). – DIY: Engine Exhaust (Dry, Wet,+). – DIY: Engine Mounting (Hard, Soft,+). – DIY: Engine-to-Marine Gear Interfaces (Adapters, Dampers, Jackshafts,+). – DIY: Marine Gears (Inboards, Inboard-Outboards, Outboards, Sail Drives, Pods,+). – DIY: Shafting (Shafts, Couplings, Joints, Thrust Bearings, Seals, Cutlass, Struts,+). – DIY: Propellers (Screws, Water Jets, Paddle wheels,+).
15.3.4 – DIY: Electrical Systems. – DIY: Direct Current. – DIY: Alternating Current. – DIY: Auxiliary Generators.
15.3.7 – DIY: Safety Equipment (PFDs, Firefighting, Alarms,+).
15.3.9 – DIY: Tenders.

16 – MEDIA w/Creator Directory (Authors, Editors, Publishers, etc) + Lending Library.
16.1 – Articles (w/Reviews).
16.2 – Books (w/Reviews).
16.3 – Magazines (w/Reviews).
16.4 – Product Documentation (SpecSheets, Installation Drawings, Manuals, Parts Books,+).
16.5 – Videos (Movies, etc. w/Reviews).
16.6 – Websites (w/Reviews & Links).

to see examples of our website's comprehensive contents!

Thanks to our amazing contributors for the steady flow of articles, and to our dedicated all-volunteer staff who sort, polish and format them, everyday we get a little bit closer to our goal of
Everything About Boats. If you would like to submit an article,
see Submitting Articles.


Ford Industrial Power Products Diesel Engines
How to Identify Ford Diesel Engines
Ford 2715E
Lehman Mfg. Co.
Detroit Diesel 8.2
Universal Atomic 4
Chrysler & Force Outboards
Eska Outboard Motors
Perkins Engines
ZF Friedrichshafen AG
Allison Transmission
American Marine Ltd (Grand Banks)
Boat Inspection
Types of Marine Surveys
Marine Surveyors by Regions
Boat Builders By MIC
Beta Marine
American Boat and Yacht Counsel (ABYC)
USCG NVIC 07-95 Guidance on Inspection, Repair and Maintenance of Wooden Hulls

What our nonprofit Anchors Aweigh Academy and its website have accomplished so far.

  • Published over 300 website main topic webpages, many with full articles on the topic. See our Website Contents in the Right Sidebar for the listing of the main topic pages.
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  • Acquired over 120,000 pages of product documentation including Catalogs, Brochures, SpecSheets, Pictures, Serial Number Guides, Installation Manuals, OpManuals, Parts Schematics, Parts Bulletins, Shop Manuals, Wiring Diagrams, Service Bulletins, and Recalls. And have made all viewable to academy members through the EAB website.
  • Acquired over 1,200 books and magazine back issues in our academy library and so far have made over 700 viewable to academy members through the EAB website.
  • Published over 500 DIY How-To articles about boat design, construction, inspection, operation, maintenance, troubleshooting and repair. We are working hard to do more.

We are currently formatting and polishing the Anchors Aweigh Academy online and hands-on courses. The Marine Surveying course has proven to be excellent for both the beginner and the seasoned surveyor, and especially helpful to the Do-It-Yourselfer.

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FROM Donald: "This is an awesome website. I found the information that I needed right away from one of the over 10,000 free articles that you provide as a public service. I'm surprised that so much if this site is free. But I still signed up so I could access the thousands of expanded pages, interesting articles, and dozens of valuable programs! The member's library of books, magazines and videos that I can view online is really terrific! I understand that you and your staff are all unpaid volunteers. Please keep up the good work. And I commend you for your plans to add another 10,000 free informative articles over the next year. I'm thrilled to support you in this endeavor with my small membership donation. Thanks again for all your hard work."

FROM Huey: "I agree with my Uncle, I too have found the articles to be very enlightening. They say that it will take about 50,000 articles to cover the full scope that they have envisioned for the website. They have over 10,000 articles so far and that's doing pretty well, but it could take several years to get the rest. I also noticed that many of the Main Topic Pages and some of the article pages are still in the rough draft stage. I guess that they will fill in as they can get volunteers to work on them. But what I can't figure out is why anyone would spend the time writing informative in depth articles just to give away free to this website for publication? What's in it for them?"

FROM Dewey: "Well Huey, to me It looks like most of the articles on this website are written by very informed people, like boating instructors, boat designers, boat builders, riggers, electricians, fitters, marine repair technicians and marine surveyors. Writing such articles helps establish them as knowledgeable professionals. After all, this website was originally created by a school for marine technicians and marine surveyors. The website is growing in content every day. They even had to move to a bigger, more powerful server on October 15, 2018 because the website's traffic has been growing exponentially."

FROM Louie: "I agree with everyone above. This site is quickly becoming the ultimate reference resource about every aspect of boats and ships for everyone from the beginning recreational boater to the seasoned professional mariner. I use the topic pages on the right sidebar to browse around the website. It's like a Junior Woodchucks' Guidebook for Boaters. Their Members' Library of over 300 popular and obscure books and over 200 magazine back issues that can be viewed online is fabulous. The Academy's magazine is especially informative. On top of that, there is the "Ask-An-Expert program for members where you can get an expert's answer to any of your boat questions. And a whole years membership is only $25. What a deal! I really love being part of this "Everything About Boats" community and help provide thousands of helpful articles free to the public. I think that I'll sit down right now and write an article about my experiences boating with my uncle."

FROM Scrooge: "You rave about this website like it was the best thing since sliced bread. Well, I think it stinks. Sure, it has a lot of good information for boaters, and they're adding more every day, but it will probably never be finished. Furthermore, I don't even own a boat. And I wouldn't have a boat even if someone gave me one. Boats are a waste of money and time and energy and money! They're just a hole in the water you pour money into. If you gave me a boat, I'd sell it quicker then you could say Baggywrinkle. Then I'd lock up the cash with all my other money so I could keep my eye on it and count it every day. Bah humbug."

FROM Daisy: "I'm just so glad that Donald got the boat so we and the boys could enjoy boating — together. And of course all of the girls, April, May, and June, love to be on the water too, especially when that is where the boys are. Oh poor Scrooge, boating is more fun then you could possibly imagine."

FROM Scrooge: "After seeing how much fun you all have on the water together, I regret that I didn't have that much fun when I was young. I've had a change of heart, and I'm giving each of you a Lifetime Academy Membership."

FROM Editor: "For those of you that have stayed with us this far, Thanks. You inspire us to keep working on this labor of love. We know that we have a lot more to do. Ultimately, we hope that we can help you enjoy the wonder filled world of boating as much as we do. We are all waiting to see what you have to say about this webpage article. And we assure you, your corrections, updates, additions and suggestions are welcomed. Let's work together on this.

FROM Tom: “I have twin 8.2s in my boat. I’ve found this article to be very helpful in understanding my engines’ weaknesses. My engines seem to be in pretty good shape. If I’m careful and follow your suggestions, I hope to get several more years of service from them. Thank you for the information. Keep up the good work. I’ve attached a picture of a V8 crankshaft that shows how narrow the connecting rod bearings have to be when two rods are attached to each journal.”

V8 Crankshaft with Two Rods assembled to each rod Journal.

FROM Scrod: “Detroit Diesel 8.2 Liter, head gasket failures (no block deck to support the liners, you’d think they would have learned from the Cadillac 4100) and bottom end problems. It doesn’t live up to the “Detroit Diesel” legend. I would avoid it.”

FROM Genesis: “The DD 8.2s are in fact diesels, and have the unit injector system that Detroits are known for, but they’re 4 strokes. They were also called “fuel pinchers”, although they were never really all that good at extracting the higher-BSFC numbers we now get from electronics. They’re parent-bore engines and have an “open” block deck design, which means that they’re prone to head gasket problems. Early year engines also had too small of head bolts for proper sealing pressures. I am generally a Detroit fan, but this is the one engine of theirs I would not own.”

FROM Mobil_Bob: “8.2 Detroit…you couldn’t give me one even if you papered it with 20 dollar bills! Cam bushings were not presized. If you replace them the engine had to have the cam bores align bored. Oil pump gearrotor bushing. Replace it and you have to mount the engine block in a Bridgeport to resize the bushing so the outer gear will fit, 15mm head studs, that later had to be drilled out in situ?? tapped to 17mm, what a joke! Monobloc free standing cylinders much like that … of an engine that cadillac had hell with. Reset the overhead, injector and racks??? baseline method using dial indicators??? insane!!”

FROM Glenn: “We had a 8.2 come in with a head gasket problem and i got it torn down before i knew what we was getting into. One cylinder was what i called bent over to the side some. When you run a straight edge on top, one side was high and other side low, just like it was trying to lay over.”

FROM Snapon Man: “I have seen several people say that the Detroit Diesel 8.2 liter engine was designed and built by the Pontiac division. I would like to know if anyone has proof that this is true. Its not hard to believe as it was used in a lot of GMC trucks as well as others and GMC and Pontiac were usually grouped together as far as dealerships went and the 8.2 was painted Pontiac blue. I haven’t found anything anywhere that says beyond a doubt that it was actually a Pontiac product. If anyone has anything connecting the 8.2 with Pontiac I would like to see it. Thanks to everyone.”

FROM Bob: “Oh yeah, the Fuel Squeezer. Real popular in the 80’s in GM and Ford mediums. The engine was designed by Detroit Diesel but was manufactured in Romulus MI. The Romulus plant was eventually transferred from Detroit Diesel-Allison Division to Chevrolet-Pontiac-Canada Division during one of Roger Smith’s (GM CEO) frequent re-org’s in the 80’s, so I guess it isn’t a stretch to say Pontiac built these things for a spell. They were indeed painted a blue very close to Pontiac blue. Were they any good? Well… My experiences were that if the 8.2L was one of the low power (165 h.p.) naturally aspirated versions, they were pretty good. No power, but very good fuel economy. However, if the 8.2L was one of the higher horsepower turbo versions (I think 220 h.p. was max) they ate head gaskets. A lot. Not only were there too few head bolts. but the block was similar to a Chevy Vega in that it was an open-deck design. The water jackets were open to the deck surface. Not much area for the head gasket to seal. Someone told me that towards the end of production GM revised the block to a closed deck design but I never saw one like that. There was a rumor going around that when Roger Penske bought Detroit Diesel from GM he specifically didn’t want the 8.2L because it was ‘junk’. Not too sure how true that was, but when that took place (1988) it was pretty clear that GM and Ford were going to stop using the 8.2L soon (1990), and GM was not going to sell the Romulus plant (they still operate it to this day making V-6 gasoline engines). I think it’s easy to see why Penske wasn’t interested in it. When the 8.2L first came out (late 1979?), I though GM had lost their minds and were going to reintroduce the Toro-Flow!”

FROM Geoff: “Toro-flow was a diesel version of the GMC V-6, V-8, V12 family of gassers. An entirely different engine then the 8.2, but same problem, not enough head bolts, for the load. Low power, poor reliability. Never really caught on either, it was built back when gas medium trucks ruled the market. Heavy diesels were covered by GM’s 2 stroke diesels and the Toro-flow was a cheap diesel for the medium market.”

FROM M.S.D.: “The engine 8.2 block doesn’t have liners like other models but its no different than rebuilding a Cat 3208. Detroit Diesel did offer a complete marine engine in 300 HP. Exhaust manifolds are identical for the Detroit and J&T models. The only odd ball manifolds were made of aluminum and were designed for the twin turbo engines produced by Stewart and Stevenson, and maybe Covington Diesel. Today, only the right bank manifold is available and its limited to which distributor has them. I am told maybe 4 or 5 units. The left bank is on back order with no date in sight for delivery. The freshwater pumps are no longer available in new or reliabuilt. Rebuild kits are available and some good shops have them for exchange. The salt/raw water pump pulley is no longer available but Depco Pump has cast a new pulley to match and offers it with a new pump. Turbo charger is another one said to not be available but a good turbo shop can get the parts new. Injectors are tricky and I recommend having the ones that came out rebuilt rather than exchange. Most injector shops don’t rebuild these, but they do send them out to the few shops left who have the equipment to do these correctly. The only problems I have seen is on the 300HP versions where injectors were exchanged. All 300HP engines have special injectors, bigger tips, and flowed more fuel. The injector body retained the lower output markings so when the mechanics ordered exchange units they went by the markings, and the result was lower power and a confused mechanic and pissed off owner. 9 out of 10 detroit mechanics don’t have the tools to work on 8.2s and when they did try to work on them they got bit. So you’ve got Detroit mechanics saying these are crappy engines and owners who believe it. Any diesel engine that gets poor maintenance, worked on by ignorant mechanics, and abused, (over worked, overloaded) will get the same results. There is much to say about this little engine as it was used for many years in many applications and with many satisfied customers. What other engine was available in that configuration (size, HP, fuel consumption) during that era that could have fit in its place? As it is now, the easiest replacement for this engine is a mechanical B series Cummins. For More $$$ go with a Yanmar, But not much else pound for pound fits in its place.

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