: 6.2/.5 chevy. what are they really like ?



briney
12-28-2007, 02:33 AM
hi guys. i am confused. on forums like this, people seem to bag the **** out of the V8 chev diesel. the most charitable people say they are gutless, but with reasonable fuel economy. where in australia, there is a mob who puts them into landcruisers, patrols and light trucks all the time. people rave on about low end torque and fuel economy. is it just that the jap diesels are pos ? all the engines get a full rebuild, and have mechanical pumps. some are sold turbocharged.

pinky49
12-28-2007, 04:00 AM
Hello,
I work at a shop where we have 4 service trucks with 6.5's in them. Only 1 of these has pretty good power and the other 3 run about like a 305v-8 smog motor. They are reliable and get around 15mpg in a 7200lb service truck, but if left stock are no speed demon.
Ed

turbos10
12-28-2007, 05:58 AM
The engines are just not a good engine. They are a light built diesel....which does not work well for the longevity batting average. The will break cranks and blocks with no warning and grenade....that is a small issue. They are also prone to crack heads. Of coures, my 12V cracked a head as well after replacing a 6.5 with it..... so I dont know if that arguement works. All jokes aside, they are prone to crack heads and to run hot. Cold starts are a bear if everything is not just so-so. And, they are also gutless. As for fuel economy, mine got 12MPG in my V3500 4x4.

I replaced my 6.5 T with a 12V cummins when it broke a PS pump pulley and over heated. I just was not going to spend a bunch of money on a chevy diesel when I could do a cummins swap for about the same money.

IHWillys
12-28-2007, 11:31 AM
Note what size the majority of the vehicles getting these swaps in Australia are.

Ken

dieselcruiserhead
12-28-2007, 01:46 PM
The 6.2 NA diesels I've driven are gutless, are not "diesel" reliable, and get horrible gas mileage. They offer no benefit, over say a gas 350, what so ever, in my opinion. They are also NA so they are severly affected by altitude and all the other issues that affect NA motors. I think they can be tuned well and are not that bad a base with a turbo potentially. but there are much better engines to start with. But as a result, they are "appropriately" priced in my opinon. The big issue I have heard from them is injection pump issues. If that can be resolved, then with a light turbo is could be a decent engine. But again I wouldn't look at one personally...

briney
12-28-2007, 06:04 PM
these are all things i've heard before about them. i guess if most of the cars they get fitted to are 4400-odd lbs. and manual, they might be ok ? the people who fit all of these engines imported my 4BT, so they're not all bad. the 1HZ ( toyota ) and TD42 ( nissan ) engines we get here wouldn't pull a sailor off your sister.

One Big Doofus
12-28-2007, 09:59 PM
My Chevy had two 6.2's that broke cranks before swaping the cummins in 10 years ago. My Dad drove one 340,000 before he died. I still have the Jimmy and drive it hunting,......Hummmm come to think of it,...You can hear it a mile away, maybe that's why I never have to clean anythang LOL

Here's a bolt on power upgrade that will give you 2/3rd's more power LOL (http://img.villagephotos.com/p/2006-11/1225528/DSC00455.JPG)

Just messin with ya!

briney
12-28-2007, 10:09 PM
2/3 more horsepower :grinpimp: :grinpimp: :dustin: seriously though, have a look at brunswick diesel and read the testimonials. www.brunswickdiesels.com.au

farmer0_1
12-29-2007, 12:05 AM
if it is going to be a driver i wouldn't hesitate owning a 6.2 or the mech version of the 6.5 . that being said it won't last as long as most cummins and the mileage is not as good . we have two 6.2s and two 6.5s on the farm with anywhere from 200k on them down to 10k. i have replace one that broke the crank after pulling stock trailer at least half its life 225k on that one. never pulled the pan or heads on any of them . pumps are cheaper and last less time. if i was going to buy a rig with something in it a gm mech inj rig is fine if i was going to take the time to put a motor in something go with cummins. i have a 93 ctd and a 91 ctd my brother uses the heck out of his 97 ctd. dad now has a dmax with a stick and i hate sensors. only problem with his dmax is that it is a stick. and the clutch is bad stuff.

ttaxus
12-31-2007, 07:55 AM
Ended my time (91-98) in Uncle Sam's Motorcycle Club (E-5, 3521) running a shop for a 155mm gun battery. Had 12-13 "hummers" all with the 6.2NA, they were run hard (lots of cold starts with ether, off road, bad drivers:rasta:) all had glow plug issues, were truly gutless - even with the insane hub gear reduction, they got the job done I guess. Only saw one with a bad IP in all that time, did see a few cracked cranks.

Military app. for this engine in a 8000lb platform was marginal in my opinion - never saw a 6.5.

Don't know if this info helps......

mudguppy
01-03-2008, 09:34 AM
....Military app. for this engine in a 8000lb platform was marginal in my opinion - never saw a 6.5......

they are all 6.5 motors in the HMMWVs now. i hate those motors. i ran the largest maintenance company on Ft. Stewart for a few years. in my time, i think we changed almost 300 engines (over a fleet of 2500 for the division), just as many heads, and at least a thousand IPs. i've seen those motors do it all: con rods, broke pistons, broke cranks, cracked blocks, you name it. and that's all after the unit has done all their maintenance (injectors, plugs, manifolds, radiators, etc). oh, and all this on what we'd consider "low mileage" - if HMMWVs made it over 20k miles on a motor it would be considered "abnormal."

i'm not exactly a big proponent of those motors.

DogDiesel
01-03-2008, 02:42 PM
I was elated when I spoke to my wife from Iraq. My 6.5 died. The 6.5 in my pickup locked up and my wife and the truck were towed home...she felt guilty for driving it when it broke.
"You're not upset?" No, I'm pulling it and putting a Cummins in it!
And now, over a 100,000 later, no regrets.

I bought my first 6.2L in 1982, and a GM diesel till 2001. I turbo the 6.2, I put low compression piston in the 6.5 and you cannot drag race volkswagons.
Well, you can, you may not win.
Wayne

jdemaris
01-04-2008, 07:41 AM
hi guys. i am confused. on forums like this, people seem to bag the **** out of the V8 chev diesel. the most charitable people say they are gutless, but with reasonable fuel economy. where in australia, there is a mob who puts them into landcruisers, patrols and light trucks all the time. people rave on about low end torque and fuel economy. is it just that the jap diesels are pos ? all the engines get a full rebuild, and have mechanical pumps. some are sold turbocharged.

"Low end torque and fuel economy" when compared to what? I've got over 40 6.2 diesel rigs - Suburbans, Blazers, trucks, etc. Mostly future projects and parts vehicles - but I have six that are road-worthy and I swap back and forth by seasons. In the winter, all my snow-plow rigs are 6.2 diesel Blazers. I also have two small 4WD motorhomes with 6.2 diesels.

I was a John Deere diesel mechanic when the 6.2s came out new. I drove many, and fixed many at that time - and ever since. My opinion is - the best thing about them is they are cheap to buy, and cheap to fix. I still find complete engines, or trucks with running engines for $150 or less. I wish I could find some Cummins in that price-range.

In regard to low-end torque - it's about the same as 305 gasser - not very much. 6.2 was originally designed to be a power-equivalent to the 305 and that's about what it is. I've seen many blow to pieces with 60K miles on them, and I had one - in my 87 Suburban, make it to 520,000 mile before the crank and block blew to pieces.

My biggest complaint is - they can be running fine - and all of a sudden - blow to pieces with no advance warning. I assume it's a quality control issue with cast-iron crankshafts and cylinder-blocks. 6.2s are prone to developing cracks by the main-bearing webs. That gets worse over time - and at some point - finally let go. When my 87 Burb blew-up - it was still starting and running like the day it was new. Eating oil, yes. But otherwise - it got 13-19 MPG, had high oil-pressure, and sounded perfect. Cruising down the highway at 70 MPH - it just all of sudden, blew-up.

It is my opinion, that any properly designed engine should die slowly and give warning - not run great up to the moment it blows.

The newest 6.5s being made now (6500 Optimizers) have much heavier heads and blocks - but the cranks are still cast-iron. Hopefully, quality control has improved.

The reality is - if you buy an engine for $150, then pull the oil-pan and check for web-cracks (and find none), you can probably get a lot of use out of it. Injection pumps are fine after 1985 and older pumps should pretty much all be updated by now. But, a 6.2 has a lot of cubic inches and will never be real good on fuel mileage. A Cummins 3.9 can make the same power - if not more - since it can handle high turbo boost and act "bigger" when needed, and "smaller" when needed.

Don't pay attention to the high failure rate in military engines - since they are abused something awful overseas. Thin fuel, high heat, and vehicles overloaded with armour. US Army says most 6.2s/6.5s last 1000 miles at best in hard use.

My best fuel-mileage 6.2 is in a 1982 K10 4WD truck withi 3.08 axles, and a four-speed manual overdrive trans. It gets a high of 24 MPG on a flat highway and 16 MPG local driving. My Blazers all get around 20 MPG, my 3/4 Burbs around 18-19 MPG best, and 1/2 ton Burbs with OD around 20 MPG.
I've also pulled a 21 foot camper thousands of miles with a 6.2 diesel Blazer and averaged 13.2 MPG for the trips.

DogDiesel
01-04-2008, 09:37 AM
Been working on them for over 25 years. Army does not get many miles from them, they suffer from typical V-8 diesel heat woes. Rear cylinders wear too quickly, head gaskets fail, and usually on rear. Culprit is usually fan clutch, time delay module, and good gracious, glow plugs, glow plugs, fail, fail. In desert heat, the engines we tore down suffered top end oiling issues, even rear cam bearings were blueing. It just don't cool well enugh.
In 96, GM up'd the water pump from 80 GPM to 130 GPM, installed dual thermostat, all attempts to fix heat woes.
Standadyne was supposed to fix pumps to allow them to function on JP-8 fuel, but still same parts, and the pumps fail to pump when hot, soldiers pour water over rear of pump, and low pressure pump tolorance returns to start hot, otherwise once running in desert, must stay running. Not uniquely a 6.2-6.5 problem, a problem for all rotary style pumps.
Since the military uses de-tuned engines, cracked blocks are not the problem of civilian more powerful engines. When I put low compression pistons in a 98 oil cooled block, it promptly cracked, the 93 non-oil block was fine, however it gave up at 44K with a broken rod brg stud. (POS)
Granted my 6.5 gave me equal fuel economy at 55-65, the 6.5 bests the Cummins at 70-80 (economy only), the Cummins replacement outpulls, outlast, and definetly out-grunts the GM V8 diesel, and well, its just better.
I not running another GM 6.2-6.5. Finished.
Wayne

johnretired
01-04-2008, 09:50 AM
Gm want to sell replacement motors and vehicles. They are built to have a short life.
Then add a lot of GM quality control, and you have a chevy v8 diesel!!!
Any correctly designed diesel should go at least 500,000 miles.
Gm has done a lot to destroy the us diesel market.
The old 5.7 was a short stroke diesel.
Who would of thought up that idea???

jdemaris
01-04-2008, 11:12 AM
Gm want to sell replacement motors and vehicles. They are built to have a short life.
Then add a lot of GM quality control, and you have a chevy v8 diesel!!!
Any correctly designed diesel should go at least 500,000 miles.
Gm has done a lot to destroy the us diesel market.
The old 5.7 was a short stroke diesel.
Who would of thought up that idea???

No, not any diesel is built to last 500,000 miles. Heavy duty diesels yes to a certain degree - but the GM 6.2 was never intended to be, nor was it marketed as a HD diesel.

Medim and Heavy duty diesels are sold with projected life-spans called "B" ratings. For example, a 5.9 Cummings diesel has a B10 rating of 210-250,000 miles and a B50 of 350,000 miles. A "B10" means only 10 do NOT make it during the miles stated without a teardown. So, even with the 5.9 Cummins, 50% do NOT make it to 350,000 miles when used hard.

6.2 and 6.5 was never B tested or rated, the Duramax has been.

GM certainly made some bad engines - but it's not them that screwed up the diesel market at the consumer level. It's mostly due to owner and repair shop ignorance. I worked on the first Oldsmobile diesels when they first came out late 70s - much being warranty work. Yes, they had some pretty bad problems - but even more so with owners who were clueless and repair shops with mechanics who were also clueless with diesels. Many still are. In fact, that time, many Chevy dealers did not know how to work on them. Thusly, many perfectly engines got pulled and swapped over to gas, or Mr.Goodwrench replacement engines.

As far a the Olds engines being short-stroked? Well, they were built to offer fuel economy duing a fuel crunch - not power. They were built over the exisiting gas-engine Oldsmobile platform - just as many - many other diesels were - including several International Harvester diesels, Hercules, Continental, Isuzu, Nissan, etc. Short-stroke can result in a wider RPM range than a HD long-stroke diesel and it's not always bad in light use. GM did not offer the 350 with a standard trans., or 4WD, or any towing - it was light-duty only.

5.7 liter 350 Olds diesel, 4.05 X 3.38, 125 horse at 3600 RPM, 225 TQ at
1600 RPM
6.2 GM bore 3.98 and stroke 3.8 highest torque rating 248 lb. ft.
6.5 GM bore 4.06 and stroke 3.8 VIN-F 240 lb. ft. at 2000 RPM
6.9 Ford IH bore 4 and stroke 4.18 (more tractor-like than a 6.2) 315 lb. ft. at 1400 RPM
7.3 Ford IH bore 4.1 and stroke 4.18 345 lb. ft. at 1400 RPM
7.3 Ford IH IDI Turbo - 4.1 bore and stroke 4.18 395 lb. ft. at 1400 RPM
5.9 Dodge Cummins Turbo 4 bore and 4.7 stroke. 400 lb. ft. at 1700 RPM

Dougal
01-04-2008, 01:44 PM
In my experience, Aussies seem to be far more tolerant of fuel thirsty engines than others.
It's probably a result of the Aussie car industry which pumps out mainly fullsize sedans and wagons with big 6's or V8's.

The fuel figures of the chev V8 diesels don't seem impressive. 13.5l/100km is mentioned in a brunswick testimonial where a stock diesel landcruiser of similar size (maybe bigger) will use 12l/100km or less.
Personally indirect injection is enough to turn me cold (without the rest). Harder starting, weaker heads and the associated fuel economy penalty.

The Aussie military fitted Isuzu 4BD1's and 4BD1T's to their landrovers in the 80's. I doubt they treat their vehicles any better than the US military does and they have a great reputation.

jdemaris
01-04-2008, 02:34 PM
The fuel figures of the chev V8 diesels don't seem impressive. 13.5l/100km is mentioned in a brunswick testimonial where a stock diesel landcruiser of similar size (maybe bigger) will use 12l/100km or less.
Personally indirect injection is enough to turn me cold (without the rest). Harder starting, weaker heads and the associated fuel economy penalty.

The Aussie military fitted Isuzu 4BD1's and 4BD1T's to their landrovers in the 80's. I doubt they treat their vehicles any better than the US military does and they have a great reputation.

Those fuel mileage figures you posted are about what a diesel Chevy Blazer here in the US gets with a 6.2 - depending on gearing, 18 MPG is about right for highway cruising (13.5l/100km). Some do a little better when geared with 3.08 axles. I know of a few Blazers with Cummins 3.9s and they do better yet - up around 25 MPG (9.25L/100Km).

In regard to how our military uses or abuse rigs as compared to Australia, I don't have a clue. But - most of the US military issues of high-failure rates are due to:
1. high heat and using JP8 fuel with rotary Stanadyne pumps.
2. retrofitted armour plates that overload many 6.2 vehicles

I assume the Australian rigs you mention probably have in-line injection pumps and also not the same overloading issues. But - I'm only guessing since I know zero about the Australian military.

DogDiesel
01-04-2008, 03:34 PM
Ironically, being cheap (built) is what doom the 5.7L Oldsmobile engine. It came with an inadequate water separator that square box filter, and the standadyne fuel injector pump did not have the water bleed off inside the pump which is now standard in the 6.2 / 6.5 MFI pumps, as well most rotary style pumps. Inside now, is a screw insert with a wire thru it, that bleeds water return back to the tank. Most of the 5.7s broke the crank. In those standadyne pumps the govenor race ring was plastic, and water and hot plastic disentigrate and when that happened the crank often broke. New engines fixed the problem in warrenty, and GM gave diesels a bad rep. All because of being made cheap.

I bought a 1979 Olds and got 420,000 on it and sold it to a fella in CA (a friend - who called me a couple years later cussing (joking) about that POS I sold him, blew the engine and stranded him in Palo Alto. How many miles are on it now, 20,000. I said do you realize that is 520,000? Yeah, he joke, now where can I get another engine. I directed him to a fella in Monterey, and last I heard he had another 200K on that engine. That car had a Racor water separator. Average fuel economy 32MPG, worst 26, best 36. Great economy, but gutless.

Most of them never made it over 100K.

Wayne

bt4mpg
01-04-2008, 05:14 PM
A stainless steel replacement ring was available for a while. The head bolts needed to be retorqued periodically and most people didn't do that. The factory usually put too much injection timing for the amount of compression too. A guy brought his Chevy pickup to my college teacher, because he didn't like the way his 5.7L Olds was running. My teacher adjusted the timing with a timing light, instead of using the lineup marks on the injection pump. It was way off! That 5.7L was one of the quietest indirect-injected diesels I have ever heard, had more power, and got 1.5 mpg better fuel economy. Another guy I knew freed up the exhaust on his 5.7L C10 and had a tremendous torque increase. He did amazing burnouts with that truck. I believe that leaving them stock and not maintaining them properly led to their problems. 30 mpg was popular! And the ones that didn’t rattle like crazy from the factory were the ones that lasted!

briney
01-04-2008, 06:56 PM
most of the n/a 4.2 diesel utes i see here give 18/20 L/100 k's. part of this is all the thrashing of them to get them to move. they wouldn't pull the skin off a rice custard. one place i worked had a 4.2 'cruiser ute, which used 100 litres of diesel to travel 500k's. this was empty, and a flat road. sitting on 100k's. in 2002, they bought a 7.3 turbo auto F250. this would pull 3 tonnes, and whaddya know used 100 L of diesel to do the same trip with a HIGHER average speed. and yes, the army flogs the 4BD1 rovers pretty hard, and they keep going. i haven't ever driven a brunswick converted car. which is part of the surprise when i looked at the website,and considered using one in my F100. thankfully i put down the crack pipe and bought a cummins.

jdemaris
01-05-2008, 08:49 AM
Ironically, being cheap (built) is what doom the 5.7L Oldsmobile engine. It came with an inadequate water separator that square box filter, and the standadyne fuel injector pump did not have the water bleed off inside the pump which is now standard in the 6.2 / 6.5 MFI pumps, as well most rotary style pumps. Inside now, is a screw insert with a wire thru it, that bleeds water return back to the tank. Most of the 5.7s broke the crank. In those standadyne pumps the govenor race ring was plastic, and water and hot plastic disentigrate and when that happened the crank often broke. New engines fixed the problem in warrenty, and GM gave diesels a bad rep. All because of being made cheap.



When the 350 Olds diesel first came out, I was working for a John Deere dealership - in which we had our own Stanadyne injection pump shop. As a result, we did many repairs for two nearby Chevy dealers who were clueless with diesels. On top of that, my boss and two co-workers bought new Chevy 1/2 ton trucks with the new 350 diesel. My boss went through three such trucks before he gave up on them. I had the opportunity to experiment on some, and do standard warranty repairs on others. My bosses first new truck made it to 70,000 miles before the head-gaskets blew. I modified the fuel filter system on it early on. After that, new gaskets failed every 2000 miles. He bought two more new trucks expecting improvement, and the newer ones did worse. The best fuel mileage he ever got - was 19 MPG with a 1/2 ton, 2WD pickup with no weight in it. The other guys in the shop that also had 1/2 trucks got the same fuel mileage, more or less.

The early filter problem was something we all knew about and was easily fixed - way before GM did it. John Deere tractors used the same basic DB and DB2 pumps and all the Deeres had water-seperators. I think GM relied way too much on Stanadyne, and should of consulted in-house, instead - with Detroit Diesel (which they did later with the 6.2).

In regard to the vent-wire you mention, it won't stop a pump from getting a siezed head & rotor when water gets into it.

With broken cranks - yeah we had many early on, which I was suspect was more a quality control problem - not an engineering problem. That's what you get when you cut corners and use cast-iron instead of forged-steel. Good castings make it, and poor castings break. This was also used in the later 6.2s and still is with the newest 6.5s. A crank that was poorly cast to start with, died even sooner than fuel delivery was turned up, or the timing advanced to far. Many 6.2s also broke cranks.

In regard to the plastic weight retainer ring in those DB pumps - it was also in all the Deeres, Cases, Fords, IHs, Allis Chalmers, etc. I don't believe they had anything to do with broken cranks. Those rings all disintergrated over time, but tended to last 10 years in industrial equipment. Not so long in the 350 diesel. The two shaft umbrella seals also did not hold up in the 350s. Stanadyne/Roosamaster claimed it was due to the insulated underhood temps in autos that got much higher than in tractors. Subsequently, the plastic material got changed three times - the last being some sort of Pellathane. Then - in mid-1985 - it was dropped altogether and replaced with the EID retainer (elastomer insert drive). Those plastic rings were always listed as "optional" by Stanadyne, and could be eliminated. When they failed, they resulted in a plugged fuel-return circuit and a no-run situation - usually nothing more than that. It takes less than hour to replace one, along with $20 in parts - once the pump is on the bench. Add an extra $30 for the upgrade to the EID.

We are in the northeast with cold winter temps - sometimes minus 35F. Our problems might of differed a bit from warmer areas. At one time, we had a mountain of 350 diesel engines out back, many that still ran when pulled. An equipment buyer from Florida bought them all, claiming they worked pretty well down south as power units. Can't say I'd want to waste my time trying it.

Our #1 problem with the 350 diesels was head-gasket failures - which usually showed up with a "no heat" situation. There was no fix. GM came up with endless updated head bolts and head gaskets - but none worked. There was not enough steel and hardware to sustain head gaskets until the big law-suit against GM and the new DX replacement blocks came out around 1981.

Our #2 problem was glow-plugs. Sounds trivial, but there weren't any adequate glow-plugs available -and when not working - people often ruined engines with constant ether starting - and some engines got replaced with gas 350 Olds engines - just because of constant glow-plug failures.

Our #3 problem was the rubber parts in the injection pumps.

In regard to GM cutting corners? Well, I wasn't there behind closed-doors. From what I read, the couple of guys the built the first few Olds diesels - had requested forged steel cranks and heavier blocks with high nickel - and those requests never made it to production.

jdemaris
01-05-2008, 09:06 AM
A stainless steel replacement ring was available for a while. The head bolts needed to be retorqued periodically and most people didn't do that. The factory usually put too much injection timing for the amount of compression too. A guy brought his Chevy pickup to my college teacher, because he didn't like the way his 5.7L Olds was running. My teacher adjusted the timing with a timing light, instead of using the lineup marks on the injection pump. It was way off!

I worked in a Stanadyne pump shop at the time - and never heard of this "stainless steel ring" you mention. What exactly are you referring to?
There was the standard steel weight retainer that was not stainless, and there was the "Roosamaster optional" plastic ring. Then later in 1985 the EID update which also is not stainless. There is also an "Arctic Kit" for thin fuels with special hardened parts (not stainless) that only updates a few parts in the fuel-transfer pump - not the governor. Kit will carry the "1.2cSt" mark on the pump.

In regard to head bolts - you could retorque till the cows came home, and the gaskets would still blow.

In regard to the timing - when using the timing light - how did he know the timing was off? I ask, because in order to know - you need info that was not easy to get at that time. The lines on the pump are nothing but static timing marks and have nothing to do with the automatic timing advance that changes timing with RPMs and load. And, to check with a timing light with a pulse adapter - the readings would be totally different than if done by GM specs that required a luminosity probe. The timing light measures injection AT the pump, and the luminosity probe measures actual combustion time - and the two are many degrees apart due to injection lag. I was doing warranty work on the engines when new - and information was scarce and there was no Internet yet. Seemed at that time that even GM had trouble getting straight answers from Stanadyne people.

bt4mpg
01-05-2008, 10:49 AM
One of my co-workers was working in Cleveland, Ohio at the time and he had purchased 3 or 4 stainless steel collars that replaced the EID. I believe he got it from a local pump shop.

My teacher in college was a Master Mechanic who had his own Diesel Truck repair shop just outside of Grants Pass, Oregon until his retirement. He had a Snap-On pulse-sensing device that clamped on an injection line. He determined TDC, etc.

DogDiesel
01-06-2008, 12:20 PM
Familiar with the luminosity probe and the clamp and meter approach for the #1 injector line.
However, with the 5.7, the 6.2 and the 6.5 I found most of them in a state of retarded timing vice too advanced.
For example, the miltary timing on the 6.2 / 6.5 in the HMMWV is at 4 degree after TDC, and most civilian engines are about 6-7 ATDC. Most of these engines I find are running 10-12ATDC by the clamp on injector line approach. When you hear a 6.2 that stumbles like a Detroit at idle, it is retarded.
However at about 3 degrees or more advanced, I found smoke cleared up, ping and heating began. 3 degrees is about as advanced as they need to run.
These engines go toward retarded timing because of slack in timing chains. In both my 6.2 and 6.5, I installed timing gears and they run much better.
We bring a fleet of HMMWV in and check timing, and usually any with any age has to be advanced. Observable perception is that military engines retard faster, likely because of poor oil change procedures, as there was a program to sample and run oil till contaminated and poor oil changes must wear chains faster.
In 1984, the 6.2 was the best engine in the US for the HMMWV. No, it was the only diesel. IH sold the 6.9 to Ford in 86 (or was it sooner) and Dodge put the John Deere Cummins in 86-87.
Now that EPA mandates (since 94) EFI systems (No MFI), and indirect injection is all but history, there really should be quality diesels in the US.
When we ran the military repower study on the HMMWV, the IH V6 powered the HMMWV awesomely.
But for some reasons, I am looking a NEW US military equipment with foreign made engines, the bigger stuff with typical Cummins, CAT, IH, Detroit power. No smaller engines.
Bottom line, My old personal diesels are aging. 81 VW pickup AAZ 1.9TD, 84 Mercedes 2.2l, 85 Mercedes3.0, 87 Mercedes, Cummins in 93 chevy and Cummins in 68 Bronco.
I am in the market for a small (NEW?) pickup or car diesel powered. VWTDI, VW Polo 3 cyl?
That old 12V I put in my chevy will still be running decades from now, but I need a daily driver for my commute. And the only choice I get is VW?

Still looking.

Wayne

jdemaris
01-06-2008, 01:10 PM
However, with the 5.7, the 6.2 and the 6.5 I found most of them in a state of retarded timing vice too advanced.
For example, the miltary timing on the 6.2 / 6.5 in the HMMWV is at 4 degree after TDC, and most civilian engines are about 6-7 ATDC. Most of these engines I find are running 10-12ATDC by the clamp on injector line approach.


Most of my civilian specs match the military specs - so I'm not sure why you find different figures. The military used many different pumps, some OEM .29" plunger 6.2 pumps, some detuned .31" big-plunger pumps to detune 6.5s, etc.

For the most part, GM 6.2 factory timing specs called for TDC at 1400 engine RPM when measured with a luminosity probe. The TDC setting equals a 7 BTDC reading if done with a timing light (approx.). Since most stock 6.2 injection pumps are at 1 to 3.5 pump degrees of advance (2 - 7 engine degrees), that puts the static timing between 2 - 7 engine degrees ATDC for all the engines - civilian and military. From what I've experienced (and many other 6.2, 6.5, 6.9, and 7.3 owners) - these engines run best overall when set at 8 - 10 engine degrees BTDC at 2000 engine RPM - but that varies with use, fuel, altitude, etc.


These engines go toward retarded timing because of slack in timing chains. In both my 6.2 and 6.5, I installed timing gears and they run much better.

I think the timing chains are a minor issue. I've pulled apart several 6.2s with very high miles and the chains were still within specs. GM allows 1/2" slop when new and up to 8/10ths of an inch of slop for a used chain. I pulled apart a 6.2 with 520,000 miles and it had 6/10ths of slop. Yes, I've seen several that ran a bit retarded, and all was needed was rotating the pump just a bit. Same goes for many Case and John Deere engines that have DB and/or DB2 pumps and NO timing chains.
The DB2 with factory timing settings is very close to a "problem" retard point, and it only takes a small bit of wear to result in poor cold starting, smoking, skipping, etc. Both my Fords with IH 6.9s and 7.3s have done exactly the same and they both are gear-drive (no timing chains).
The DB2 is prone to getting a sluggish timing advance - due to housing wear against the advance piston. That seems to be the biggest wear problem with the pumps and timing.


In 1984, the 6.2 was the best engine in the US for the HMMWV. No, it was the only diesel. IH sold the 6.9 to Ford in 86 (or was it sooner) and Dodge put the John Deere Cummins in 86-87.

What is a John-Deere Cummins? I never heard of it and I worked for Deere for close to 40 years. Are you saying they had some sort of joint-venture?
Case and Ford tractors used Cummins - never heard of the Deere thing.





Bottom line, My old personal diesels are aging. 81 VW pickup AAZ 1.9TD, 84 Mercedes 2.2l, 85 Mercedes3.0, 87 Mercedes, Cummins in 93 chevy and Cummins in 68 Bronco.
I am in the market for a small (NEW?) pickup or car diesel powered. VWTDI, VW Polo 3 cyl?
That old 12V I put in my chevy will still be running decades from now, but I need a daily driver for my commute. And the only choice I get is VW?

Still looking. Wayne

There's going to be a bunch of them soon in the U.S.A. for light vehicles. Two new small V-6 and V-8 Cummins, a new Honda, two new small GM diesels, etc. The new GMs appear to be designed and made in Italy.
GM is also testing a new diesel engine that runs on gasoline (to work around diesel emissions).

http://i104.photobucket.com/albums/m162/jdemaris/29GMbdiesel.jpg

dieselwrangler
01-09-2008, 04:14 PM
well we just picked up a Chevy 1ton dually crewcab with a 6.2 diesel and it also has a banks turbo kit on it and even with that turbo I think my NA 7.3 Ford crewcab dually will outrun and outpull it the 6.2 has a TH400 and my Ford has a ZF5speed the chevy get 13 empty and the ford will do 15-18MPG I think with a OD the chevy would egual or better the ford but it still dont pull like the IH 7.3 and is a Bitch to start when there is air in the system we also have a 4bt powered truck it will outrun out milage out start and just plain out last the chevy a 4bt is a good swap for a chevy 6.2 powered truck

afking1981
01-11-2008, 04:39 AM
I've been on this site doing research and learning all I can for about a year now. From what I can gather most of the folks in this thread are trying to place the 6.2L up against the B-series Cummins design, which is unfair at best.

The 6.2L was designed by Detroit Diesel as an answer to the gas crunch of the late 70's and early 80's (read: 1/2 ton diesels for 2009 and beyond). It was never designed for enormous amounts of power nor earth-shattering performance numbers.

Bear in mind also that GM put this motor into production lines starting in 1982 and the design stayed largely the same until being replaced by the Duramax in 2001. Also debuting in 1982: the launch of space shuttle Columbia, MRI's, and the first artificial heart transplant. Nowadays we are sending remote control cars to Mars, viewing full color ultrasounds of fetuses, and studying limb regeneration for amputees. Technology advances.

Most of the problems experienced with this motor is due largley to overloading, it is not an industrial engine like the Cummins. The 6.2L was specifically designed to drop into a small block Chevy engine compartment- it matches up with the SBC motor mounts as well as the bell-housing pattern.

Some common issues associated with the 6.2L:

-Broken cranks result from harmonic balance failure. The rubber ring rots and separates, causing vibrations in the crank that usually result in catastrophe.

-Main web cracks are an issue, aftermarket stud girdle kits are available.

-Injection timing is often a problem as the timing chain stretches out. Aftermarket replacement timing gears are available.

-Cooling issues with this motor are very common and are somewhat alieviated by adapting the dual thermostat setup from a 6.5L to the 6.2L.

-Cylinder heads do crack but most do not affect performance.

-Glowplug issues are common in 2 areas: controller failure and the glowplugs themselves. Many will simply bypass the controller with a toggle switch and replace the glowplugs with AC Delco 60G which are self limiting to prevent burnout.

If you are looking for a hotrod diesel engine the 6.2L is not your ticket. A B-series engine is a proven design platform and will yield what seem to be nearly limitless results depending on your level of finance. However, this is not to say that the 6.2L isn't a reliable engine that will get you where you need to go and back again.

I own an 83 K10 Suburban and an 88 C1500, both with naturally asprirated 6.2L's. Both are good daily drivers that give me 20 and 24 mpg respectively. Alternately, if I have some heavy hauling to do, I leave that task to my 97 2500 Cummins. I'll only get 18mpg but I won't blow my up my motor on the way there. It's apples and oranges.

For a quick numbers comarison:

http://en.wikipedia.org/wiki/Detroit_Diesel_V8_engine

http://en.wikipedia.org/wiki/Cummins_B_Series_engine

For all the 6.2L information you could ever possibly want:

http://www.thedieselpage.com


Just my 2 cents:)

jdemaris
01-11-2008, 08:50 AM
From what I can gather most of the folks in this thread are trying to place the 6.2L up against the B-series Cummins design, which is unfair at best.
The 6.2L was designed by Detroit Diesel as an answer to the gas crunch of the late 70's and early 80's (read: 1/2 ton diesels for 2009 and beyond).

I'm not so sure about that. Yes, GM had the 6.2 designed as a power-equivalent to the 305 gas engine during a fuel crunch. But . . . things changed a bit since 1982. GM upped the fuel delivery, installed a turbo, and and boosted power a lot - using the same basic engine format. They sold thousands of the engines to our military for extreme use. That was GMs idea - not some guy jerking around at home in his gargage. GM did this without changing over to a forged-steel crank like Ford-IH diesels always had. GM did not significantly beefed up the block, nor the heads, and offered little improvement with the Stanadyne rotary injection pump - which has failed miserably with thin-fuel use.



Most of the problems experienced with this motor is due largley to overloading, it is not an industrial engine like the Cummins.

I don't believe that for a minute - show me some verifiable stats. I was doing warranty work for GM when the Olds-350s diesels came out - and later when the DD 6.2s came out. They had different problems - but few were assoiciated with overuse.

With the 6.2s specifically - many got ruined due to poor glow-plug systems. When the plugs don't work, many people would over-use ether and ruin engines.

Also - many 6.2s suffered broken cranks under light use and low miles. We had a few come in that broke at the back where the flywheel mounts. With some, the engines sill ran with the flywheel broken off. Others broken near the front, often ruining the block. The fact is - there was no definite observable "cause-and-effect" - and subsequently it appears to be mostly a casting quality control issue of the crankshafts. Some broke at low miles with light use, and many lasted high miles with heavy use.



Some common issues associated with the 6.2L:

-Broken cranks result from harmonic balance failure. The rubber ring rots and separates, causing vibrations in the crank that usually result in catastrophe.

Show me some test results, or any kind of official stats proving that.
From what I've seen and read - the cranks had quality control issues and few problems with the harmonic balancers. If a crank is poory cast to start with - it may indeed suffer even more from a bad harmonic balancer - but that is NOT what I'd call a balancer problem. It's an engine design problem.



-Main web cracks are an issue, aftermarket stud girdle kits are available.

Yes, they are indeed a major issue and there has been no testing to indicate the web-girdles accomplish anything. I admit, they do look good.
GM acknowledged much of the cracking problem is due to the casting alloy for the block, lack of mass - all of which is weakened further by the main-bearing-cap bolts that were too large. GM made them smaller in the later engines. GM reduced the size of the 12 mm outside main-cap bolts to 10 mm to reduce cracking. The newest engines - not made by GM and now called the 6500 Optimizers - have beefed up blocks with high-nickel content and heavier heads - but are still using cast-iron crankshafts.



-Injection timing is often a problem as the timing chain stretches out. Aftermarket replacement timing gears are available.

Not sure about that really being a problem. GM allows 1/2" of chain stretch with a used chain and 3/8" when new. I've pulled apart many 6.2s with over 400,000 miles on them and the chains were still within wear limits. It apppears that stretch significantly at first and then stay somewhat stabile. My highest mile 6.2 that I pulled apart at 520,000 miles had a chain still withing wear limits. GM has the static timing set on 6.2s so just a small amount of wear makes them skip and start hard cold. Some of that is due to slight timing-chain wear that is easily rectified by bumping up the static timing by moving the injection pump.



-Cylinder heads do crack but most do not affect performance.

Many crack and certainly do affect performance. Granted - most all 6.2 cylinder heads get surface cracks around the precombustion chambers that don't hurt anything. But - many 6.2s with large-valve heads crack severely between the valves which ruins the heads beyond repair. On many older 6.2s - the lower power C-code engines had large valves and cracked under heavy use. The HD J-code engines often had smaller valves, leaving more metal between them and thus less severe cracking. But, even the J-codes will crack when overfueled and overheated.
6.2s also had other cracking problems around the glow-plug bores and was fixed by pressing in steel bushings.

Examples of valve sizes:

In regard to valve sizes - many of the J code HD engines I've pulled apart have 1 1/2" exhaust valves and 1 3/4" intakes. My 87 3/4 ton Suburban had these heads and I pulled it apart after the crank broke at 520,000 miles - and the heads were still fine.

Most of the LD C code engines I've pulled apart have 1 5/8" exhaust valves and 1 15/16" intake valves. This includes the first 1982 model year heads with coarse-thread injectors casting # 14028901


-Glowplug issues are common in 2 areas: controller failure and the glowplugs themselves. Many will simply bypass the controller with a toggle switch and replace the glowplugs with AC Delco 60G which are self limiting to prevent burnout.

Yes the AC Delco 60Gs work good - mainly because AC Delco does not make them. They are made by the German company Beru and put into Delco boxes.


However, this is not to say that the 6.2L isn't a reliable engine that will get you where you need to go and back again.

As I already said, I've been working on them since they were invented and still own over 40 of them. Not because they are great engines - more because they are cheap and parts are common - used and new.
Some last a very long time and some died early deaths - even when lightly used and well cared for.

My biggest complaint is this. In my opinion, no engine should blow up with no warning. I've been a mechanic for 40 years - and can think of very few that did not die slowly and give many warnings - when used reasonably and were well cared for. Not the 6.2. Since it is prone to cracking at the main-bearing webs - it gets worse and worse over time with no for-warning at all. Many run perfect up to the moment they blow to pieces.

One example of many is my 87 Suburban 3/4 ton 4WD. It was used for camping, off-roading, farm use, trailer towing etc. since it was new. At 520,000 miles it still ran perfect, sounded perfect, started perfect (as a 6.2 gets), etc. The only wear sign was excess oil consumption - about a quart every 500-1000 miles. I had routinely pulled the injection pump every 150,000 miles and went through it as preventive maintenance. Also put new injection nozzles in at every 150,000 miles. At $4 each - it's cheap insurance. Otherwise the engine had never been apart. Just a few water pumps and vacuum-pump pods. Then, one day crusing down the highway at 70 MPH - empty - it blew to pieces. No warning signs at all. Later, after pulling it all apart, I was surprised to find the pistons, cylinder walls, and all crank bearings to look excellent with very little wear. The block was broken in many pieces as was the crankshaft. And - the harmonic balancer still looked fine. Rubber still soft and all intact.

I can't gripe about getting over 500,000 miles out of it - but I will gripe about any engine that can go like that with zero advance warning.

I now pull the oil pans on all my 6.2s and check the mains. It's not easy, especially since all mine are 4WD. I've already removed three perfectly running engines and scrapped them for parts because I found them cracked.



I own an 83 K10 Suburban and an 88 C1500, both with naturally asprirated 6.2L's. Both are good daily drivers that give me 20 and 24 mpg respectively.

I assume - if you are referring to US gallons - and not Canadian - you are citing absolute best mileage figures and not average? I've been driving 6.2 trucks, Blazers, and Suburbans since new. The best I ever got - with my 82 K10 4WD, 1/2 ton truck with 3.08 axles and four-speed manual OD trans - was 24 MPG on a hot day, flat highway, at 60 MPH with a breeze at my back. 21 MPG is more of the highway average - and 17 MPG around town.
My 91 1/2 ton Suburban 4WD with 3.42 axles and 700R4 OD auto-trans has gotten up to 21.5 MPG at best.
My 3/4 ton Suburbans with 3.73 axles and TH400 auto trans all get up to 19 MPG highway. My Blazers with 3.08 axles - regardless if with 700R4 OD trans - or TH400 trans all get a best of around 21 MPG and 16 MPG around town.

http://i104.photobucket.com/albums/m162/jdemaris/62J_codeheadcrack1b.jpg

http://i104.photobucket.com/albums/m162/jdemaris/62Jcode1989precupcrack1.jpg

http://i104.photobucket.com/albums/m162/jdemaris/webcrack004uy2.jpg

http://i104.photobucket.com/albums/m162/jdemaris/P1010001a2028Small29.jpg

nhdiesel
01-11-2008, 05:48 PM
I'll back up the opinions of the GM diesels. The largest vehicle they were marginally useful in was a Blazer, if you didn't work it hard. As others have said the military goes through these things faster then they can change the oil. Recently I saw several military auctions on www.govliquidation.com of 650 6.2/6.5 diesel cores EACH auction!

Jim

95Z28A4
01-12-2008, 07:40 PM
and some engines got replaced with gas 350 Olds engines

Been there, done that. We replaced a 350 diesel / metric 200 tranny in a 1981 Pontiac Parisienne with an Olds gas 350 / turbo 350 from a 1973 Cutlass. The diesel had 55k miles when the head gasket blew. The gas engine & tranny had 56k miles. Owner was elated with the swap and got many years of reliable service from the conversion.

nhdiesel
01-12-2008, 08:27 PM
Kind of funny, but all of the posts I see defending the 6.2/6.5 are claiming that the engines are worked too hard, and were built for economy rather than power. O.K., I would let it off the hook if they were put in passenger cars like the old 350 diesels. But they were put into 3/4 and 1-ton trucks, and the 6.5s were put into 3500HDs. I'm sorry, but anyone buying one of these vehicles will be pulling trailers, hauling heavy loads, and generally making the engine do what the truck was designed to do. These weren't soccer mom rigs or economy cars. They are TRUCKS. If they age quickly and become unreliable pulling a 10k lb. trailer their whole life, then they are junk. If one out of many failed early, I would be impressed. But you have to look hard to find someone bragging that their 6.2 went 200k+ miles. If I were to guess, I would say that maybe 10% of 6.2s made it to 200k. At that I think I'm being very generous. Its probably more like 5% or less. On the other hand, its a rare Cummins that has any serious problems before 200K, or even 300K miles. I'm not counting 24 valves...they have their own issues. But the 12 valve 5.9s, as well as 3.9s, are extremely durable.

I would also give the GM diesels some credit if they made gobs of torque and were real workhorses, but didn't have a long lifespan because of the power levels they put out. But its quite the opposite. They are gutless. Combine gutless with a very short lifespan and it adds up to a P.O.S. engine. There is really no defense for an engine that was put into work trucks that can't handle working.

Jim

jdemaris
01-13-2008, 08:13 AM
Kind of funny, but all of the posts I see defending the 6.2/6.5 are claiming that the engines are worked too hard, and were built for economy rather than power. O.K., I would let it off the hook if they were put in passenger cars like the old 350 diesels. But they were put into 3/4 and 1-ton trucks, and the 6.5s were put into 3500HDs.


I agree 100 % - and I LIKE the 6.2s - mainly because they are so common, convenient, and cheap.

The Olds 350 diesels weren't even sold with 4WD or in anything heavier than 1/2 ton - and - no towing was allowed. Two of the mechanics I worked with had them, and also my boss who bought three in a row - thinking each new one would be better than the last - but that never happened. All 2WD 1/2 ton trucks. All those trucks eventually got converted to Olds gas -engines and then sold. I know very few people who were satisfied with the gas-conversions. Not because there was anything wrong with them - just the big drop in fuel mileage and lack of diesel "smoothness." The last one my boss had - lost its head gaskets for the second time at the 60,000 mile mark. He then had a Olds gas 350 installed - and fuel mileage went from 19-20 MPG highway to 9-11 MPG highway. He got digusted - and finally bought a new S10 4WD with a 4.3 gasser and never looked back. In 1983 - we needed a new 1 ton service truck for our John Deere dealership - and GM tried to sell us a truck with a 6.2, and Ford a 6.9. We bought the Ford with the 6.9 diesel - a dually 1 ton truck loaded very heavy with a service-crane, tools, a press, etc. We ran it for years with zero problems - it was bullet-proof. After the Ford experience, we never went back to GM for any service vehicles.


With 6.2s, I often buy good runners (complete 6.2 4WD trucks) for $300 or less. New parts are dirt cheap too, as compared to parts on newer diesels. And, look at the used parts market. Try to find used engine parts for a 5.9 Cummins, or a Ford-IH 7.3 and they're scarce and costly. But the 6.2s? Since so many get scrapped, parts are cheap and pretty easy to find. One prime example is the injection pumps. I've got a mountain of Stanadyne DB2s -and I've never paid more than $25 for one. One the other hand, I've been looking for years for a spare "back-up" pump for my 94 Ford 7.3 turbo IDI and also for my 92 Cummins 5.9 tubo-intercooled with the Bosch VE pump. The Ford pump is rare and expensive - and the pump for the Cummins extremely expensive - and also rare for sale off an engine.
I've been looking for a buy on a Cummins 4BT engine for a long time (with GM setup) - around $1800-$2000 near me in NY. Haven't found one yet. On the other hand - I find countless 6.2s. Just got a "package deal" from a local farmer. Someone traded him three GM diesel trucks for 100 square bales of hay. He then sold them to me for the grand total of $250. This includes a 1982 K10 truck with snow plow and 6.2 still good running, an 83 Blazer with a low mile 6.2 and blown 700R4 trans, and a 89 3/4 ton 4WD Suburban with a replacment 6.5 engine and a rod-knock. All for $250 - and the farmer feels he made out since the hay-value was only $150.

By the way - back to subject of 6.2s gettting used heavy. They were also installed in several 13,000 pound class-A motorhomes, which was an incredible mistake e.g. 1983 Itasca 27 foot Suncruiser, 1991 Alexxa Odyessy 28 feet, 1982 Champion 23 foot, etc. Many got upgraded to 6.5s, and then to Cummins or Isuzu engines.

Also, there are the many GM P-series bread vans that came OEM with GM 6.2 diesels or 350 gassers and Ford-IH 6.9s. Many of the 6.2 diesel versions got repowered with Cummins 4BT kits.

briney
01-13-2008, 08:19 PM
also, when i rang up a couple of places about putting one of these engines in my F100, i was quoted $10000.for a rebuilt engine, a few accessories and a the adaptors for the vehicle. making a killing much ? even hummer pull out running 6.2's over here are $3850. how hard is it to get a green card ? i might swap countries.

averagef250
01-14-2008, 09:19 PM
Briney, shouldn't cost you much to get a 6.5 shipped over there. Get someone over here to take one apart and ship it in smaller boxes. Since the blocks and cranks are usually in several pieces this is fairly straightforward.

Dougal
01-14-2008, 09:37 PM
Briney, shouldn't cost you much to get a 6.5 shipped over there. Get someone over here to take one apart and ship it in smaller boxes. Since the blocks and cranks are usually in several pieces this is fairly straightforward.

:smokin:

briney
01-14-2008, 11:05 PM
Briney, shouldn't cost you much to get a 6.5 shipped over there. Get someone over here to take one apart and ship it in smaller boxes. Since the blocks and cranks are usually in several pieces this is fairly straightforward.

:D :D :D :D


i would like to repeat an earlier statment. i put down the crackpipe and bought a cummins.

CrewCab59
01-19-2008, 06:53 AM
Here is a 6.2 for ya.Makes no since why anybody would install one of these engine new or used just to find out this was going to happen.

Scott

DogDiesel
01-19-2008, 07:16 AM
If I had it to do over, I'd have installed locktabs on rod bearing nuts. Great running 300HP low compression engine, but at 44k did similar to above pic on #5. Converted to Cummins ;).
BTW- culprit was the rubber deteriorated on front pulley damper. It died while I was gone for a year with my wife driving it occasionally, so her guilt was green light for a Cummins install.
Since I had ceramic coated heads & exhaust Manifolds, had a Peninsular turbo, marine pump, high pop injectors, when I started parting it out, I recouped my cost for the 5.9L.
6.5s are Like drag-racing old air cooled VWs.
Wayne

Wayne

steve
01-29-2008, 05:10 PM
i have a 6.5 turbo in a blazer fullsize 94. it goes along ok i gess. the ejector pump went already 140,000 miles 800 dollars later needless to say it just doesnt look like a solid built engine and sounds like a gas engine with a rod nock im selling mine...

ShadeTreeMech
01-30-2008, 05:51 PM
Is there such a thing as an excellent v-8 diesel?

Dougal
01-30-2008, 09:34 PM
Is there such a thing as an excellent v-8 diesel?

The rangerovers 3.6L V8 seems to be making friends. Audi has had a V8 diesel around the 4L mark for quite a while.
In the US, you'd be looking at pretty big trucks.

dieselwrangler
01-31-2008, 09:48 AM
such for the question of a good v-8 Diesel im in favor of the early Ford/Navistar 6.9 7.3 non turbo and turbo we have a few and my current truck a 94 with a NA 7.3 has 205,000miles with no probs so far it still has the original injector pump and injectors ill be changin them sometime this year tho just cause its time

IHWillys
02-01-2008, 11:19 AM
Is there such a thing as an excellent v-8 diesel?

Detroit Diesel 8V-71.

Ken

DogDiesel
02-01-2008, 02:05 PM
The Detroit 8V-71, I disagree is not a good engine. If I had a dollar for every one I have changed, I'd could fill my 85 gallon truck tank at current prices. Thats a lot of engines.
Very maintenance intensive, failed injectors, rack adjustments needed, not prone to longevity, except when not load-unloaded. If they run a genertor or a pump, they last real well, but on-road, and constuction, they are well below average.
v-8 Diesels are prone to cooling problems, lack the bearing contact surface area of inline engines, etc.
Like listening to them, but know that noise is work coming.
Wayne

JakeDiesel
04-03-2008, 11:45 AM
The only reaons that I would buy anything with 4.3, 5.7, 6.2, 6.5 diesel in it would be to take it out and put the 4bt in. Then I would take what ever one it is and take it to a scrap yard, because to me that is all they are worth. I know a bunch of people who have them, and know of only one that has been okay for the guy, all the others have given them seriuos problems. (cracked heads and blocks, throwing rods, etc.)

jdemaris
04-03-2008, 12:08 PM
The only reaons that I would buy anything with 4.3, 5.7, 6.2, 6.5 diesel in it would be to take it out and put the 4bt in. Then I would take what ever one it is and take it to a scrap yard, because to me that is all they are worth. I know a bunch of people who have them, and know of only one that has been okay for the guy, all the others have given them seriuos problems. (cracked heads and blocks, throwing rods, etc.)


Sounds like you don't know the right people and don't know the engines. I've been working on, and driving 6.2s since they first came out. I still own over 40 vehicles with 6.2s. I've had one failure. That was my 87 3/4 ton 4WD Suburban that blew to pieces at 520,000 miles. Before that, the engine had never been touched internally. It got a few routine injector changes, I rebuilt the pump twice as routine maintenance, several water pumps, vacuum pods, etc. It was running like new 10 seconds before it blew up. Main webs let loose in the block and the crank snapped into three pieces. When I later stripped it for parts, the pistons, bearings, etc. look hardly worn. The heads also - have no cracks and I'll be reusing them on something else.

6.2 heads crack for two reasons. The most common one is abuse. Pump gets turned up too far in efforts to make more power, the EGTs fly, and the heads overheat and crack. Second most common is using the wrong heads for hard work. Light duty heads have large valves with very little metal between them. They crack easy. Heavy duty heads have small valves and much more metal between them. They virtually last forever is you watch your EGTs.

Why you choose to lump 4.3s and 5.7s in the same group as 6.2s and is beyond me. 4.3s and 5.7s were designed by Oldsmobile. 6.2s and 6.5s were designed by Detroit Diesel.

6.2s offer a real bargain as far as cost goes. But, for a rugged engine with better efficiency, you can't beat a Cummins. To be fair - the 6.2 was originally designed for light duty use only, nothing more.

I can buy good running complete 6.2s for $150. I can buy good used injection pumps for $25-$50. Try to find Cummins parts or engines in those price ranges.

I'm building a 3.9 Cummins rig right not. Not because I'm afraid of GM 6.2s, more because I want better fuel mileage potential. I could buy 10 -12 good running 6.2s for the price of one Cummins 3.9.

scrapman32
02-01-2010, 12:08 AM
I was wondering if (Directed to dogdiesel ) what about the Diesel engine that was put in the Isuzu pup pickup ? Drove one a few years back and wondering if it was a good or bad engine

Dougal
02-14-2010, 12:55 PM
I was wondering if (Directed to dogdiesel ) what about the Diesel engine that was put in the Isuzu pup pickup ? Drove one a few years back and wondering if it was a good or bad engine

Sounds like the Isuzu C223.
Yes it was a good engine, but it's small (2.2 litres) and hence not very powerful. There are turbo versions but they're still low boost indirect injection engines which don't compare well to modern tdi's of similar size.

tiger04
02-15-2010, 07:31 PM
Sounds like you don't know the right people and don't know the engines. I've been working on, and driving 6.2s since they first came out. I still own over 40 vehicles with 6.2s. I've had one failure. That was my 87 3/4 ton 4WD Suburban that blew to pieces at 520,000 miles. Before that, the engine had never been touched internally. It got a few routine injector changes, I rebuilt the pump twice as routine maintenance, several water pumps, vacuum pods, etc. It was running like new 10 seconds before it blew up. Main webs let loose in the block and the crank snapped into three pieces. When I later stripped it for parts, the pistons, bearings, etc. look hardly worn. The heads also - have no cracks and I'll be reusing them on something else.

6.2 heads crack for two reasons. The most common one is abuse. Pump gets turned up too far in efforts to make more power, the EGTs fly, and the heads overheat and crack. Second most common is using the wrong heads for hard work. Light duty heads have large valves with very little metal between them. They crack easy. Heavy duty heads have small valves and much more metal between them. They virtually last forever is you watch your EGTs.

Why you choose to lump 4.3s and 5.7s in the same group as 6.2s and is beyond me. 4.3s and 5.7s were designed by Oldsmobile. 6.2s and 6.5s were designed by Detroit Diesel.

6.2s offer a real bargain as far as cost goes. But, for a rugged engine with better efficiency, you can't beat a Cummins. To be fair - the 6.2 was originally designed for light duty use only, nothing more.

I can buy good running complete 6.2s for $150. I can buy good used injection pumps for $25-$50. Try to find Cummins parts or engines in those price ranges.

I'm building a 3.9 Cummins rig right not. Not because I'm afraid of GM 6.2s, more because I want better fuel mileage potential. I could buy 10 -12 good running 6.2s for the price of one Cummins 3.9.
i have a 95 k 3500 373 gears 60 horse chip 9 resister 5 sp it will sart any day below 0 does not have a block heater gets 18-24 mpg has 250000 had 1 pdm 2oil pres sender i pull a 24 foot pro stock traler all over love it but if it comes un done i have a 90 5.9 cummins to put in it in the shop floor right now i have tried to tear it up to get in faster but no luck for over a year