Detroit Diesel 8.2L

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^ Detroit Diesel Overview, History, Contact Information with Links, etc.
^ Detroit Diesel 8.2 Overview & History. Shortcomings: Heads, Pistons, Bottom End, etc.
^ How To Keep the 8.2 Alive.
^ What others have said about this engine.
^ Similar Engines from Major Competitors.
^ Detroit Diesel 8.2 Specifications, Years Manufactured, and Duty Ratings. Serial # Guide.
^ Documentation: Catalogs, Brochures, SpecSheets, Manuals, Parts Lists. Recalls, etc.
^ Forum Posts, Tech Notes & Tech Tips.
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Detroit Diesel Corporation

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 8.2L "Fuel Pincher"

Detroit Diesel 8.2 Litre “Fuel Pincher” Marine Engine with Turbocharger (Not Intercooled)

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 8.2 became available in a turbocharged version. Eventually, the 8.2 was marinized by DDC and a few third-party companies (including Johnson & TowersStewart & Stevenson, and Covington Diesel) and fitted into vessels. The turbocharged models with the higher horsepower ratings incorporated an intercooler. Stewart & Stevenson marinized a version with Twin Turbos & no Intercooler/aftercooler.

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 mistaken belief that the 8.2 was an adaptation of an existing gasoline engine. While this is true of some other engines like the ill fated GMC 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 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 production was moved 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 move to an automobile division may have contributed to the mistaken belief that the 8.2 was a gasoline engine to a diesel engine adaptation.

8.2 Shortcomings

The 8.2 has several serious shortcomings that makes it a very poor candidate for marine service. They include a “throw-away” parent bore cylinder block, a tendency toward frequent head gasket failures, a short service life, and a weak “bottom end”. These are detailed below followed with suggestions on “how to keep the 8.2 alive”.

Parent Bore Cylinders

Most diesel engine blocks are cast and machined to receive replaceable wet cylinder liners the Cummins V-555 below. The bore of these liners are machined to fit “standard” bore size pistons. The 8.2’s cylinders are cast and machined (e.g. bored and honed) directly into the engine block casting to fit “standard” bore size pistons. This is called “parent bore” or “native bore”. Most gasoline automobile engines are “parent bore” engines. If a “parent bore” engine block has suffered excessive wear, or cylinder damage such as from overheat scoring or rust pitting, the cylinders are 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 light duty engines, the blocks can be reused by being bored and sleeved back to standard bore size by pressing in a repair sleeve. Rebuilders that have attempted to use repair sleeves in the 8.2’s cylinder bores have found that because of the weak “free standing” cylinder walls, the block will not hold a repair sleeve in position for very long especially in marine service. In addition, when the cylinders are machined oversized for larger diameter pistons or 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 even more prone to head gasket failure (see next topic below) and cylinder 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 automotive and marine 8.2 “take-outs” simply being scrapped, often when the vehicle or vessel is repowered, many with Cat 3208s, as many consider the 8.2 not worth repairing. Occasionally, used 8.2s appear for sale, such as on the internet, but after close examination they are often found 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, but the other engine may be serviceable or at least salvageable. A proper engine survey and/or a reasonable price may reduce enough risk that it provides a possible solution.

Head Gasket Failures

The 8.2 head gaskets most often fail between one or more of the cylinders’ combustion chambers and the water jacket that surrounds the cylinders. This breach allows the engine coolant to enter the cylinder during each intake stroke, the compressing fresh air to enter the cooling system during each compression stroke, and the combustion gases to enter the cooling system during each power stroke and exhaust stroke. Additional engine coolant may enter the cylinder during the latter part of the exhaust stroke, Hydrolocking, which is when enough liquid has entered the cylinder to stop the piston, is 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.

Cummins V-555 “Triple Nickel” Cylinder Block with replaceable “Wet” Cylinder Liners Removed.

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 Cummins V-555 “Triple Nickel” block above. Unfortunately, the cheaper Detroit Diesel 8.2 engine block shown below has neither.

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

The Detroit Diesel 8.2 cylinder blocks were cast without the full head gasket mating surface (the “deck” or “firedeck” as it is sometimes called) leaving the joined “siamese” cylinders “free standing” as clearly seen in their brochure above. The 8.2 “firedecks” consist of just the narrow top ends of the cylinders. There is no connection or deck between the tops of the cylinders and the engine block. Detroit Diesel advertised that the reason for this was for better, more even cooling, but while this is true, the real reason behind this design was to leave the top of the cylinder casting open and accessible to allow a more precise locating of the mold during the casting process which allowed the block to be cast thinner and consequently lighter as it did not require as much safety margin thickness for “mold slip”, This of course also made casting cheaper. Unfortunately, this reduced the surface for the head gasket to mate to and allows the top of the “free standing” cylinders to flex back and forth and work against the head gasket when the engine is running especially at higher power output. This 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) and then pushing even harder against the left side of the cylinder during the power stroke (see second yellow arrow). This is all due to the changing angle of the connecting rod to the crankshaft’s rod journal as the crankshaft turns.

The Detroit Diesel 8.2L Service Manual describes in section 1.1 the procure for checking the flatness of the top of the block after the head has been removed to determine if the head mating surface (the “deck”) is flat enough to hold a head gasket. If the top surface varies by more then .07mm (0.003″) transversely or more then .17mm (0.007″) longitudinally, the block must be “rejected”. Engines that had blown head gaskets were frequently found to be beyond these limits and the blocks could not be reused and had to be scrapped. The cylinders in these blocks were actually bent to the side by the pistons during power strokes as illustrated by the yellow arrow above, especially in engines that were lugged.

This “deckless” free standing design makes the 8.2 engine prone to head gasket failures and the resulting internal damage which tends to be catastrophic. Operation of the 8.2 at flank (full) speed in marine service is not wise unless the propeller is somewhat “under-pitched”, allowing the engine to run more easily. Compare the 8.2 cylinder block pictured two above and three below which lacks “the deck” with another popular V8 diesel engine, the Caterpillar 3208 whose cylinder block shown below was produced with a full head gasket mating surface (“deck”) that naturally supports the cast-in-block “Parent Bore” cylinders.

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

The last of the 8.2 cylinder blocks (including the record 50,000± engine spares produced in 1990) were reportedly cast with a “Full Deck” for each head in addition to being machined to receive the larger head bolts described below. If true, these features should have reduced head gasket failures considerably. Be on the lookout for 8.2 engines with these “Full Deck” cylinder blocks.

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 higher head bolt torque and thus were supposed to help better hold the heads to the block. It is 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 solve the inherent weakness of the 10 bolt “free standing” design. In fact, it proved to increase the distortion of the head and block where they mated to the head gasket resulting in more uneven compression of the gasket. The head gasket itself was redesigned and made stronger, and this also helped. But be careful, some after-market head gaskets are inferior and as a consequence more prone to failure. Fortunately, these weaker head gaskets can usually be identified by visual comparison to the later, stronger genuine Detroit Diesel gasket.


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, bending the connecting rods, twisting the crankshaft, stretching the main bearing caps, etc.

Detroit Diesel 8.2L Block. Note the open space all around the “free-Standing” joined “siamese” cylinders.

In the case of the particular 8.2 engine pictured directly above with the head removed, the engine shows evidence of engine coolant leaking past the head gasket and into the cylinders. “Water Washing” is the term coined by this author to describe the effect that 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. The pattern typically originates at the water’s point of origin (such as a leaking head gasket) and spreads across the combustion chamber surface. This effect can be seen on the tops of the pistons (especially the far right piston) in the 8.2 pictured above. It is very unusual 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 form steam and exit through the exhaust port during the exhaust stroke. However, if antifreeze continued to leak into the cylinder(s) after the engine was shut-down as in the case of the above engine, and then the engine was cranked by the starter motor with coolant in the cylinder(s), hydrolocking of the piston(s) and damage to the connecting rod(s) is likely to have resulted. In addition, the crankshaft would likely have suffered twisting damage and the main bearing caps and saddles, stretching and cracking damage from the extremely high loads on the already weak “bottom end”. Like many other 8.2 engines, any hydrolocking would have undoubtedly made this particular 8.2 engine unrebuildable. But only very close examination of this engine will reveal that it is too damaged to rebuild. Unfortunately, many unrebuildable engines have been rebuilt and have consequently suffered early failure.

Engine Expected Service Life and Piston Skirt Length

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 piston(s), the ring(s) and the cylinder bore(s). 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 additional wear. 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. The exception to this rule is the super-long-lifed Crosshead engine which needs little piston skirt as it has a separate piston rod and slide bearing above the connecting rod’s wrist pin to carry the side-loads (see Crosshead engine below right).

Short-Lifed 8.2                        Long-Lifed Cat                 Crosshead

Also compare the distance from the crown of the piston to the first compression ring on each piston. The distance is much less on the 8.2 piston which makes it more vulnerable to damage from engine overheating, thermal runaway (note scoring), 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 at 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”.

Crankshaft and Bearing Failures

Unfortunately, the 8.2 suffers from a weak “bottom end”. Reports of “broken cranks”, “spun bearings” and “thrown rods” are far too frequent. This weakness (which is common of most smaller “V” cylinder configuration engines, especially those with cylinder bores less then 5 inches (or 127mm) is due to the overall shortness of the crankshaft. There just isn’t enough room for the connecting rod bearings, the crankshaft main bearings, and the crank webs. The bearings don’t have enough width to adequately maintain the lubricating oil film in the bearings and support the heavy loads of a high compression diesel engine especially at higher RPMs. Even though the connecting rod journals (sometimes called pins) on the V8 crank are the widest journals on the crank, when assembled, the V8 crank will have two connecting rods crowded onto each rod journal making the journal half as wide per rod which makes the journal very narrow for each rod bearing unless the engine has extra space between the cylinders on each bank which is rare, making the whole engine longer. In the illustration below, it is easy to see how narrow the rod bearings have to be when two rods are fitted to each journal. Note the two oil feed holes per rod journal (one for each connecting rod). Also note how narrow the five main bearing journals are. They will be discussed in more detail 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.

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.

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. The main bearing journals of the V8 crankshafts shown above have been increased in diameter to increase the bearing surface in an effort to compensate for their narrowness, but this is counterproductive because the increased diameter increases the 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 bearing journals are smaller in diameter to reduce bearing surface speed and are wider so they can more easily maintain oil film thickness and carry the loads. 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 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 “bottom end”. 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 rod bearing and main bearing surface speeds. As bearing surface speeds increase, so does the risk of faster bearing wear and even failure.

The above comparisons show why smaller V8 engines that lack the space for the wider crankshaft bearings and 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. 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 difficult to obtain. 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 and must 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, other then soft parts (gaskets, seals, overhaul kits, etc.) are typically very expensive and are becoming more scarce. New major parts (ie blocks, heads, crankshafts, etc.) are practically non-existent and usable used parts are becoming very 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 often 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 certain carbon reducing and injector cleaning fuel additives 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 usually detonate in the cylinders and cause 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 ok. Well it proved not to be ok 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 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 (keep it clear of obstructions), the raw water pump impeller, the heat exchanger, the engine coolant (antifreeze), the pressure cap, all hoses, and the engine belts. 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. 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. Always maintain the proper oil level in the engine. Always replace the oil filter during every oil change. 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. 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 fill the oil galleys and bearings before starting the engine.

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.

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, you might also want to start budgeting for a repower.

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” 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 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!!”

Marinized Detroit Diesel 8.2L Four-Stroke-Cycle V8 Diesel Engine with Turbo & Intercooler.

Similar Engines from Major Competitors

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. 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 quite as much. 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 strived to strengthen the “bottom end” which they succeeded in only slightly, but they did nothing to remedy the camshaft gear weakness.

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

⊕ = Data from Multiple Sources. ⊗ = Data Not Available from Data Source. ? = …? = ¿…? = Unconfirmed.
DS = Data Source: D = Detroit Diesel. BD = = …B. Wik = Wikipedia.
^  …d = Directory. …w = Webpage. …y = Years Mfr’d History. …c = Catalog. …b = Brochure. …s = SpecSheet.
^  …o = Owner’s/Operator’s Manual. …m = Service/Repair/Technical/Workshop/Shop Manual.
^  …p = Parts List/Manual. …h = History. …f = Forum. …1,2,3,A,B,C,etc = Source #, Version, Revision.
CYL: Cylinder Orientation & Configuration-Number of Cylinders:
^  Cylinder Orientation: u… = Upright (Vertical).
^  Cylinder Configuration: …V = V Pattern.
BORE & STROKE: …mm = Millimeters. …in = Inches = …”.
DISPLACEMENT: …cc = Cubic Centimeters (cm³). …L = Litres/Liters. …ci = Cubic Inches (in³).
BRAND: ^ = Base Engine Manufacturer. ⇒ = Engine Marinizer/Mariniser.
MODEL: Full Engine Model Number w/Codes – Rating.
^  Rating: See the Engine Duty Ratings at the end of the Table.

ASP: Aspiration-Fueling: N = Naturally Aspirated. T = Turbocharged. TT = TwinTurbo. …i = Intercooler.
^  Diesel: M = Mechanical Injection.
POWER: kW = Kilowatts. BHP = Brake Horsepower. MHP = Metric Horsepower.
@RPM = Power Ratings @ Revolutions Per Minute.
YEARS MFR’d: Beginning-Ending. Trailing “–” (Dash) without an Ending Date = Still in Production.

Click on Data Source (DS) Links below for Catalogs, Brochures, SpecSheets, Operator’s Manuals, Shop Manuals, etc.

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

Detroit Diesel 8.2 Marinized by Stewart & Stevenson with Twin Turbos & No Aftercooler.

Detroit Diesel Automotive Duty Ratings

CON = Continuous
INT = IntermitantMIN = Minimum
MAX = Maximum
Gross = Gross Power

Detroit Diesel Industrial Duty Ratings

CON = Continuous
INT = Intermitant
MIN = Minimum
MAX = Maximum

Detroit Diesel Marine Duty Ratings

CON = Continuous
INT = Intermitant
PC = Pleasurecraft

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

Year MFR'd Beginning Serial Number Number of 8.2L Engines Manufactured each year
1979 870 ¿1‚510? (Production started near end of year)
1980 2380 ¿23‚934?
1981 26314 ¿23‚307?
1982 49621 ¿18‚105?
1983 67726 ¿22‚822?
1984 90548 ¿25‚097?
1985 115645 ¿30‚000? (including ¿5‚000±? spares)
1986 145645 ¿24‚274?
1987 169919 ¿24‚475?
1988 194394 ¿20‚163?
1989 214557 ¿16‚256?
1990 230813 ¿69‚197? (including ¿50‚000±? spares)
1991 300010 ¿2‚000±? (production ended first part of year)
NOTES: Suffix = 8G From Detroit Diesel Engine Serial Number Guides Dy1 & Dy2.

Engine 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
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Detroit Diesel brochure – 8.2L Advantages [Db] — DD-GM.
SpecSheets/Data Sheets:
Detroit Diesel SpecSheet – 8.2L Automotive Engine [Ds1] — DD-GM.
Detroit DieselSpecSheet – 8.2L Industrial Engine [Ds2] — DD-GM.
Detroit Diesel SpecSheet – 8.2L Marine Engine [Ds3] — DD-GM.
Charts and Graphs:
Press Releases (by Date = YYMMDD):
Model History:
Serial Number Guide (Manufacture Date Code Identification):
Detroit Diesel Engine Serial Number Guide #6SE266 [Dy1] — DD-GM.
Detroit Diesel Engine Serial # Guide [Dy2] — Depco Power Systems.
Installation Instructions/Manuals:
Installation Diagrams & Drawings with Dimensions:
Detroit Diesel Drawings w/Dims – 8.2T (4082-8300) — DD-GM.
Detroit Diesel Drawings w/Dims – 8.2T (4082-8301) — DD-GM.
Detroit Diesel Drawings w/Dims – 8.2T (4083-7366) — DD-GM.
Detroit Diesel Drawings w/Dims – 8.2T (4087-7336) — DD-GM.
OpManuals (Owner's/Operator's Handbooks/guides/manuals):
Parts Schematics with Exploded Views & Parts Lists:
Detroit Diesel Parts Catalog – 8.2L #6SP152DD-GM.
Parts Bulletins:
Shop Manuals (Repair/Service/Technical/Workshop):
Detroit Diesel Service Manual – 8.2L #6SE421 [Dm] — DD-GM.
Wiring Diagrams:
Service Bulletins:
Product Recalls:

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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:
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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.

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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 your hard word. I’ve attached a picture of a V8 crankshaft that shows how narrow the connecting rod bearings have to be.”

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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