6.2 years to avoid?

[Thesiger]

In my long journey of suburban hunting, I've run across quite a few 6.2s. But a recently remembered someone saying how early 6.2s where prone to block cracks, which go me thinking, is there a noticeable lifespan benefit to buying say a 1991 6.2 versus a 1984 one with the same miles? Are there years that are worse than others?

 

[Blue Ox]

I'd have to check my notes, but there was a point I'm going to say in the early 90s when the extended the main bolt length a bit. It helped, but the final fix was to go to an 8mm outer bolt. Unfortunately I think that was after production shifted entirely to the 6.5L.

For reference, my 2nd engine, which I think we installed around 1988 lasted 200K before the crank broke.

 

[Thesiger]

So then is there a simple fix I could do you proactively stop that? Like I'm looking at a 6.2 with only 106K on it, what reinforcements can I do to get her to 300K?

 

[Blue Ox]

There is a girdle that somebody makes for the middle three main bearings. I would think it would require some machining tho. And honestly the one I saw looks like it's cobbled from angle iron. I don't know how beneficial it actually is.

Studs may improve longevity, but the real problem is the block's main webs are just too thin. That's why going to the smaller outer bolt helped. It left more meat in that area.

The only real "fix" that I know of is the P400 engine that the military is getting now. It has a greatly reinforced bottom end, but it's crazy $$$.

Rumor has it that the '82 blocks had a high nickel content and weren't prone to cracking. The tradeoff there is the one-year-only cylinder heads were.

 

[Blue Ox]

So then is there a simple fix I could do you proactively stop that? Like I'm looking at a 6.2 with only 106K on it, what reinforcements can I do to get her to 300K?

BTW, plenty of them make it to 300K with no issues. It's a bit of a dice roll.

 

[Thesiger]

Absolutely, but how much should a worry about major failures if I'm planning to not do any pulling? I want it for the good mileage. So I'm not towing, how much of a difference does that make?

 

[Big Ray]

my 90 6.2 had 385k when it died. Motor is good, fuel system needs some love. Of course, I can't say if it's the original engine. But it ran like a champ, until it didn't. I have a built replacement i.p., and injectors. Need a new fuel tank and fuel lines replaced.
3/4ton burb, 2wd, 6.2, th400, 3:73 gears
17 mpg.
I have a used Banks kit for it, but lost the pass. side manifold when I moved in 2018. That and an overdrive should get me 20 mpg.

 

[Blue Ox]

Absolutely, but how much should a worry about major failures if I'm planning to not do any pulling? I want it for the good mileage. So I'm not towing, how much of a difference does that make?

I never towed with mine. It was just a daily driver.

 

[Blue Ox]

my 90 6.2 had 385k when it died. Motor is good, fuel system needs some love. Of course, I can't say if it's the original engine. But it ran like a champ, until it didn't. I have a built replacement i.p., and injectors. Need a new fuel tank and fuel lines replaced.
3/4ton burb, 2wd, 6.2, th400, 3:73 gears
17 mpg.
I have a used Banks kit for it, but lost the pass. side manifold when I moved in 2018. That and an overdrive should get me 20 mpg.

It's been a long time, but didn't Banks use the stock manifold on the driver's side? Or maybe the pass side manifold turned backwards?

I never had any love for that guy. It was a cr@p kit that was riddled with engineering flaws. But hey, stick a turbo on anything and you can make it go. That and lots of marketing will make you famous.

 

[Big Ray]

Pass. side looks like this: most important part of the kit!

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Never dealt with him, but I have read from various folks he can be a *****.
I've never driven a turboed 6.2, but it's got to be better than n/a!
I just like diesels. I use to drive semis, listening to my kitty cat purring at night put me right to sleep!

 

[Blue Ox]

Ahhh. Passenger side. I should learn to read.

 

[Big Ray]

you and me both friend!

 

[Big Ray]

before I give up on it I'm going to tear my garage apart, top to bottom to make %110 sure it's gone.
I'm only %98.9 sure right now. I've located several comple new kits, but my truck ain't worth it. Hell, I have a brand new IH turbo in the box. Same one Gail used originally and charged $800 for.
I get beyond disgusted sometimes...

 

[Thesiger]

Sounds like you have too much fun stuff in your garage

 

[Itali83]

Just buy the truck you like. Then just look for a spare motor. I’ve got 3 spare 6.2’s and only one 6.2 truck. I am a bit of a parts hoarder and can’t pass up a “deal” though. The fuel system gets expensive but I run a little 2 stroke oil in the fuel to help lubricate the pump. Makes me feel better.

Ben