Is this guy confused?

[1968CHEVYC10]

http://houston.craigslist.org/pts/1984492878.html
is this guy confused? is that even possible? I've been seriously considering a 6.2 diesel swap, if it's true I'm thinking I want to stay away, but if it really is a legit 6.2 I'm thinkin this could be a good start.

[dwcsr]

GM came out with a diesel in the early 80's that was made from a gas motor. It was their first foray into auto diesels and it didn't go well. I don't remember if it was badged a Detroit but it was a 4 stroke not a Detroit 2 stroke. The injector pumps were crap and you needed a spare on hand to run it. It was a bad motor and many owners converted to a 350 gas engine. So if you want an old diesel mechanics opinion stay away.

[1968CHEVYC10]

appreciate the input, I think I will stay away!

[05crewcab]

I am about 99% sure the "converted" diesel engines never made it into trucks. I think it was only in the Olds and Cadillacs and was 5.7L. It was based on the gas olds rocket V8 and was REALLY weak in the heads/head bolts. I think it was a totally GM product...I dont think Detroit had any part in it. The motor was total junk. It got to the point where people would buy brand new cadillacs with that motor and drop in a gas 350 and be cash ahead.

The 6.2 is infact a Detroit Diesel, but it was designed as a diesel from tip to tail. It's in thousands of trucks both millitary and civilian and is a good motor.

That dude is confused.

[Stocker]

^^ That sounds right to me.... or at least that's the way I remember it.

[freelancegenius]

They did indeed make it into trucks... iirc Half-ton 2wd models only for a few years around 1978-80. They were intended to be a super fuel efficient option for people who didn't use their truck like one; They weren't rated to haul much more than the passengers and light bed loads.
Technically an Olds engine and possessing a BOP bellhousing pattern, but not just "built" or "converted" from a Rocket 350. They had multiple design problems.

If it's a 350 Olds, stay away. However, he's probably confused and has a 6.2 at a reasonable price.

[rollinhard]

The ones that I've seen were in short box 2 wheel drive 1/2 tons and came with badges that said they should not be used to tow anything.
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[flashed]

Back in 1980 or 81 my boss at a pipeline company bought a new 1 ton dually with a diesel engine in it .This truck was loaded and came with a tool body on it .It was definetly one of the converted gas engines .That truck was worthless ,no power ,could not haul or tow anytghing .Also could not keep a clutch in it due to having to ride the clutch to get it to move .We hated that truck more than any old one we used .

[Clyde65]

I worked at a GMC dealer in the mid 80's and these were options that were meant to be easier on gas but still give the pulling power of a truck, however, like has been said they were oldsmobile 350 engines and they were a dealer nightmare cuz all the issues it had, If I remember right they had oil starving issues primarily, or maybe oil leaks, these and other reasons is why the 6.2 was created in the mid 80's which was a vast improvement but not the best Detroit could have done.

[stich626]

the olds 350 diesel is fine.. add new headgaskets and arp studs and it run forever

600k+ on mine

[rollinhard]

found this info on them on another forum
Quote:
LF9 Diesel

The LF9 was a 350-cubic-inch (5.7 L) Diesel V8 produced from 1978 to 1985.
Applications;

350N 1978-1985 Chevrolet, Buick, Oldsmobile, Pontiac, and Cadillac cars
Early 120 hp (89 kW) 220 ft·lbf (300 N·m) torque
Later 105 hp (78 kW) and 205 ft·lbf (278 N·m) torque
350N 1978-1980 GMC and Chevrolet light trucks "pickups"
125 hp (93 kW) and 225 ft·lbf (305 N·m) torque
Variations;

1978-1980 Early block Identified by "D" cast into both sides of block
Up to 125 bhp (93 kW)
external EGR from 1978-1981(single stud air cleaner)
internal EGR from 1982-1985(2 stud air cleaner)
Rumored that some early main and head bolt holes were not tapped to bottom
Used a conventional flat tappet hydraulic camshaft/flat tappet hydraulic lifters which required 3000 mile oil change intervals.
1981-1985 Improved block Identified by "DX" cast into both sides of block
Up to 105 bhp (78 kW)
Internal EGR
Fully tapped head bolt holes
Longer main bolts with fully tapped holes in block
Newly introduced roller lifters/rollerized camshaft extended oil change intervals.
Diesel differences;
The Oldsmobile diesel is believed by some to be a converted gasoline engine. While they share the same bore and stroke and some external bolt patterns (transmission and exhaust manifolds) they are quite different.
GM began with a substantially different bottom end when compared with its gasoline cousin.

Diesel blocks
3" diameter injection pump mounts are cast into the top of the lifter valley
Camshaft nose modified to incorporate injection pump drive gear
Block castings are much thicker and heavier. It's possible to overbore the cylinders by 0.125in without sonic testing.
Solid heavy cast main webs were used.
Reputedly GM used a higher nickel cast iron alloy for the block and heads.
Diesel crankshafts
Nodular Iron used in all Diesel cranks
Main bearing journals increased to 3.000"
Vibration damper modified to allow eccentric for crank-driven fuel lift pump
Diesel pistons and rods
Diesel rods are shorter at 5.886" long.
Diesel pistons have large valve reliefs and steel inserts behind the first compression ring.
Fuel systems;

No OEM fuel/water separator was factory installed on any Olds Diesel.
Crank eccentric driven fuel lift pump mounted in same location as gasoline fuel pump.
Fuel line heater between lift pump and filter.
Intake mounted 10 micrometre fuel filter.
Stanadyne Roosamaster DB2 mechanical diesel injection pump.
1978-79 Pencil Injectors held in by clamp.
1980-85 Poppet injectors screw into head.
Heads;

The same 10 head bolt pattern as their smallblock gasoline cousins.
The same exhaust manifold bolt pattern as their smallblock gasoline cousins.
Have injector pre-chambers and glowplug bosses.
Valve springs contained a vibration dampener with rotators.
Head variations;
Very early castings were stamped D3 and used 5/16" injector hold down retaining bolts and clamps.
D3A castings were created a little later and used 3/8" injector hold down bolts and clamps.
Both D3 and D3A heads accepted external EGR and pencil injectors.
Some D3A heads accepted poppet injectors as well.
D3B Later heads
All had internal EGR
Pencil or poppet injectors
1 or 2 locating dowels
The Oldsmobile diesel gained a reputation for unreliability and anemic performance that badly damaged the North American passenger diesel market for the next 20 years.[6][7]
[edit] Oldsmobile diesel problems

[edit] Head bolts

GM used "torque to yield", commonly known as "stretch" or "angle torque", head bolts. This allowed the bolt pattern to remain the same as the gas powered counterpart with an increase in clamping load when compared to standard head bolts. A total of 10 bolts per head were used. Four per cylinder with the center three pairs shared. This permitted the use of the same tooling and reduced setup costs. This design did not provide adequate clamping force under the severe conditions these engines were subjected to. Overheating or excessive cylinder pressure can breach the seal of the head gasket and in severe cases break the bolts.
High strength aftermarket head bolt sets are now available to make the engine more reliable in this area.
[edit] Pump timing

The Stanadyne pump was chain driven. With normal use, the chain stretches and the pump delivers fuel too late. The pump timing could be adjusted to return to normal operation.
[edit] Water in fuel

Arguably a major portion of the real problem would have been quite simple to avoid. A water separator was not part of the fuel system on these engines. A diesel run in an automobile will pick up water contaminated fuel.
Water will rust the steel internals of the fuel system. Rust will damage the precision parts in diesel fuel injection pumps and high pressure diesel injectors causing erratic operation. Injecting fuel too much prior to TDC on the compression stroke will cause pressure conditions similar to pre-ignition / detonation in gasoline engines. Water in varying amounts will also be injected with the fuel charge. Any rust in the steel fuel lines, fuel filter, pump etc can damage replacement parts and continue to cause injection cycles out of time.

[WIDESIDE72]

I think a lot of people confuse the 5.7 converted Olds with the 6.2 Detroit. The 5.7's were in fact installed in 1/2 tons in 80/81. Their failure led to the introduction of the 6.2 detroit. It was a better, but not great replacement. My dad and I ran an 82 Suburban to 350k miles and it was still going, not using oil even, when someone offered me $800 for the engine alone. Since it never was a barn burner, I bit, and parted the truck out. He said that 82 blocks had higher nickel content, which was why it still had such good ring seal. He rebuilt it and put a Banks turbo on it.

[special-K]

The 5.7 was built off the tough for gas Olds 350 block starting in '78.It wasn't a great motor compared to today,but was at least a responsible effort by GM to offer the alternative of diesel.The primary fault was the pick up screen for the oil pump.It clogged and starved the motor of oil.If that plastic piece of crap is removed it solves that problem...if you can find one.
In '82 GM introduced the 6.2 built by Detroit-Allison and '82 is the best year due to the higher nickle content in the block.The same specs were continued on the military 6.2s

[primrrd]

I drove a friends caddy eldo with a diesel and it was a TURD!!!!
I smile when I remember you could floor it and literally it just made more noise! It wouldn't get out of its own way!

[GmtGmt]

both are good engine if they are taken care off
the 6.2 was never build on a gas engine but it will bolt up to sb mounts
also pretty sure the 5.7 diesel wasent build on a gas engine eigther

they both arnt power houses but if they are taken care of they are relibel and good work hourse, the 5.7 weaknes was the head gaskets, poor fuel and people ran them like a gas engine

[BLE 'BURBAN]

Originally Posted by GmtGmt

both are good engine if they are taken care off
the 6.2 was never build on a gas engine but it will bolt up to sb mounts
also pretty sure the 5.7 diesel wasent build on a gas engine eigther

they both arnt power houses but if they are taken care of they are relibel and good work hourse, the 5.7 weaknes was the head gaskets, poor fuel and people ran them like a gas engine

They were converted olds 350 engines. I've seen many and worked on a few of them myself years ago.
Mondello's performance oldsmobile parts I believe even offer a kit to change a 350 diesel BACK into a gasser engine.
http://mondellotwister.com/

[Number21]

Originally Posted by BLE 'BURBAN

They were converted olds 350 engines.

They may have been largely based on Olds 350s, but, they weren't simply converted. The block is entirely different, and stronger. (although not strong enough, apparently)

As much of a turd of a motor as it was, it shouldn't be dismissed so quickly - the 1978 Chevy Half ton with a 5.7L diesel was the FIRST EVER diesel pickup in the American market.

[GmtGmt]

Originally Posted by BLE 'BURBAN

They were converted olds 350 engines.

they share the same bore and stroke and some external bolt patterns (transmission and exhaust manifolds) but they are quite different.

theres a guy on diesel place they runs 2 rebuildt 5.7s one in 1993 3/4 and a 78 1/2. they have been more reliebel then the gas 5.7

for what they are they great but alot of people hate them because they are very under powered but they should not be discarted, when they are taken care off and run proberly they will run forever most Trucks and vans here that have 6.2 have over 400k on them and they are still running strong