Economy/MPG driven IDI build?

[david85]

Thought about the 6.2 myself but when you consider what the nightmoose was able to do, I think the MPGs of the 6.2 have more to do with the fact that they were offered in lighter 1/2 ton frames with an overdrive transmission than some special feature of the engine itself. Being lighter is an advantage though. They are barely over 700lbs if I remember right.

I would imagine if trucks like my F150 with 3.55 gears and 33% overdrive would have probably delivered some crazy high MPG numbers if they were available with a 6.9 back in the day. I know there are F150s out there from the early 80s getting low 20s for MPGs out of the 4.9L inline six (carburated).

 

[dakotajeep]

This info was gathered from forgetten diesels.com:


6.2 L General Motors Diesel
The 6.2 L replaced the 5.7 L Olds in GMC/Chevrolet trucks in 1982. The engine was manufactured by Detroit Diesel, a division of General Motors at the time. The 6.2 was introduced as a fuel-efficient alternative to the gasoline V-8 lineup, appearing at a time when consumers were focused on fuel efficiency more so than power. The naturally aspirated 6.2 was no powerhouse, although it was a reasonable alternative for those who wanted a pickup, but didn't necessarily need the high torque output offered by competitors.

6.2 L GM Specifications:
Manufacturer: Detroit Diesel
Production Years: 1982 - 1993
Applications: GM/Chevrolet C/K trucks, Hummer H1
Configuration: V-8
Block/Head Material: cast iron block, cast iron heads
Displacement: 379 cubic inches, 6.2 L
Injection: IDI
Aspiration: naturally aspirated
Max Engine Speed: 3,600 RPM
Peak Horsepower: Introductory: 130 HP @ 3,600 RPM
Peak: 143 HP @ 3,600 RPM
Peak Torque: Introductory: 240 lb-ft. @ 2,000 RPM
Peak: 257 lb-ft. @ 2,000 RPM
Reputation: Reliable, durable, powerful for its era.

Additional 6.2 L Information:
•Replaced the 5.7 L Olds diesel for GMC/Chevrolet trucks.
•The 6.2 L engine option cost less than $1,500.
•6.2 L was capable of achieving better fuel economy than some of General Motors V-6 engines.
•Engine weighs approx. 700 lbs.
•6.2 L powered trucks were federally rated up to 20 MPG city & 23 MPG highway.

 

[david85]

I thought I read some where that the 6.2s were good for up to 160 Hp. Would it be harder to find a turbo for them? I know banks made kits, but I wonder if they are as common as on the 6.9s.

 

[91f2504x4]

I thought I read some where that the 6.2s were good for up to 160 Hp. Would it be harder to find a turbo for them? I know banks made kits, but I wonder if they are as common as on the 6.9s.

If it is like everything else GM, you could probably put a turbo kit from the 6.5L on the 6.2L. That is one decent thing about GM, it seems like everything is interchangeable, where as with Ford you have different transmissions for, small block , big block , and then diesel. Typically Many GM parts are interchangeable throughout their entire production run. Not that I am a GM fan, but I have worked on many of them and that is one thing I appreciate about them.

 

[Alex S]

If it is like everything else GM, you could probably put a turbo kit from the 6.5L on the 6.2L. That is one decent thing about GM, it seems like everything is interchangeable, where as with Ford you have different transmissions for, small block , big block , and then diesel. Typically Many GM parts are interchangeable throughout their entire production run. Not that I am a GM fan, but I have worked on many of them and that is one thing I appreciate about them.

ya same i have always loved the interchangeably that GM does any engine to any transmission, i think there still using that same bellhousing


on a turbo note the 6.5 turbo system bolts on the 6.2 and Banks still makes a kit, I know my bros suburban is no power house but id say its good enough. and it has always been reliable and always started

 

[dakotajeep]

david85

The post was saying that the stock engines varied from 130 to 143 Hp in the varying years. Its not meant as a "this is what the engine can take" information.

If thats what you were refering to....

I think I will stay on the Ford side of the IDI house for now!

Thad

 

[91f2504x4]

Speaking of the old GM diesels, I went to an antique/classic truck and tractor show tonight, and there were NO IDI's there to represent us proudly, but there were a couple old 6.2L GM's (one in a suburban and one in a pickup) There were a couple old IH trucks there, but both were gas engines.

It was mainly antique road tractors, farm tractors and a few older trucks, I had no idea there would be anything from the 80s-90s IDI era, but I really wish there would have been a good old IH IDI there. I would have taken mine there but I really feel like mine isn't good enough to be put on display, mine is just a good old truck.

 

[Alex S]

from the banks site

http://www.bankspower.com/products/show/156/11

You must be registered for see images attach

 

[91f2504x4]

from the banks site

http://www.bankspower.com/products/show/156/11

You must be registered for see images attach

Is that for the 6.2L? That is a pretty significant gain!

 

[Alex S]

Is that for the 6.2L? That is a pretty significant gain!

ya check out banks page, i guess they still make the kit

*edit* wow blast from the past a Banks add (sort of)

http://www.youtube.com/watch?v=YMAIJy73h0Q

 

[dakotajeep]

over 30% increase in HP and over 40% in torque.

Definately a big difference....

THad

 

[david85]

This topic reminds me. I saw what looked to be a bone stock 1991 chevy 1500 regular cab 2wd at the fuel cardlock a few months ago. The middle aged driver was waiting in line at the diesel pump, but my first clue was the sound when he drove up. It wasn't a gasser and suspected a diesel repower so I asked him "what do you have in that thing?".

He pops the hood to reveal a nice clean dark red cummins 4 BT. I think he said the power was around 130Hp which I thought was low, but he said the truck did fine even at higher speeds. That era of chevy is a wind tunnel truck and it was pretty low to the ground, so I'm tempted to believe it. Considering what the original 6.2s had, its not out of line for such a light 2wd 1/2 ton.

He said he was getting 25-30 MPG which is also believable considering how light and sleek the truck was (now was that canadian or US gallons?....Hmm....). His only complaint was the engine is a little shaky. I know light automotive 4cyl diesels typically have silent shafts to correct this, I can only imagine what the shifter in his truck must have felt like with your hand on it. I THINK he had some sort of 5 speed tranny, but I forgot to ask what it was exactly. He was saying it had a tendency to run too cool so as an MPG experiment he was going to take the fan off to see what sort of fuel economy gains he would get on an upcoming trip. Talking to him was probably the last straw that made me try that fan mod .

Never saw him again and didn't have a camera with me but his conversion seemed to be a really nice clean setup. The truck was in great shape too. Yes, I just complemented a chevy with a cummins in it

 

[Diesel JD]

If my brother ever sells his Isuzu Trooper I might buy it from him and try to stick some sort of diesel in there. It's a SWEEET truck. The gasser in there sux at 11mpg but the rest of the vehicle kills. I was thinking 4bt but a 6.2 might bolt right up to that Isuzu tranny and yes there were a lot of GM parts on that thing.

 

[Ironman03R]

A friend of mine has a 90 F250 XL 2wd N/A 7.3 w/ ZF5, 3.55's and a small light flatbed and it gets in the 20's on the highway. I know it was at least 22 but I think it might have been 24. The truck has 400K miles on it and the only thing it has different than stock is a K/N air filter with the cowl air mod and a 3 inch exhaust w/ bullet muffler.

 

[FordGuy100]

Well, a regular cab long bed. 2wd. 3.55 rear end. ZF-5 speed, gearvendors overdrive or gear splitter. 6.9 diesel with stock tuned pump with good injection system. Turbo, like an ATS wastegated turbo but with a smaller exhaust housing. Want lots of boost cruising, thinking a smaller exhaust housing would help with that. 235/85/16 Highway tread type tires.

There you go. I've gotten 19.7mpg with my setup minus turbo. Last couple fillups were 18.5mpg but I wasnt taking it to easy . Overdrive would help me a ton.