6.2L Diesel

i bought a 85 GMC 4X4 with the 6.2L diesel and i was wondering could these engines handle a turbo off a 4320 deere or somethin like that they only make 20 psi ill put on a pyrometer and boost gauge so i can watch them things or would that boost just kill it and it has about 215k on it

I got one, I wouldn't trust it very far with any boost on it.

I'm no expert but I believe you'll just cause an early death. As a 6.2 owner I can tell you it was intended to be the "305 cid" of the diesel engines. A light duty. Its good for its purpose but just barely cools ands has a just minumum bottom end. The 6.5 was pretty much what you're talking about and it was nothing to write home about.

The only boost it will need, will be from a set of jumper cables.

would not do it. Might cause between cylinders. See if Banks makes a torbo for this engine. if not, there is a reason. For a little extra hp disconect the EGR valve under the air cleaner.

The 6.5 actually had the SAME lower end, even the same main bearings, and put out a LOT more HP with the turbo.

The later 6.5's turbodiesels actually had a WEAKER lower end than the 'ol 6.2's 'cause the late 6.5's had extra oil passages drilled in the block for piston cooling nozzles. And, of course, they broke up worse.

A 6.2 with a turbo can actually last quite a while with a little commons sense use, and DEFINITELY has some "snort" although I can't say if a surplus Deere turbo would be a good match.

There's getting to be some used Gale Banks 6.2 turbo setups coming up for sale at more reasonable prices all the time.

David, you posted: "See if Banks makes a torbo for this engine."

Yup.

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We have one in a blazer and it runs very strong, granted it doesn't do any towing but is about the most reliable engine I've ever seen. We don't plug it in, it was in the single digits for a week, and after glow plugs cycled it fired off on the first roll after not being run, better than any dodge/cummins I ever owned. Banks and ATS made one, but I'd say a TO4 wouldn't hurt it making 10psi or so. I thought someone said that the aftermarket kits made between 10 and 15 psi. Make your own setup, buy aftermarket, or use one off of a 93 6.5L with a different turbo (air research). I dont know about your truck but ours is the heavy duty mdel engine without EGR valves, etc.

actually the best setup is a 6.5 with 18.5 to 1 marine grade genuine gm pistons and use you old 6.2 pump and ingection lines, we used banks kit instead of 6.5 turbo. needs to have diferent glow plug setup and good block heater for cold starts. has great bottom end torque that starts at 2100 rpm

Diesel needs alot of air to run, they only have enough air at idle, any RPM above that it needs more air so a turbo will definately help it but it wont stand 20psi boost. I like the 6.2 and 6.5 neither makes an abundance of power but if they are not abused they run a long time.

I"ve got a 93 with a 6.5 with anti-freeze in the oil, but the turbo should still be okay if you"re interested in any parts. Lee

Had 'em. Turboed them. My advice, find a Cummins.

thanks for all the replys i guess ill leave it alone for now and save up for a banks kit and not make some junk yard one out of a shiwtzer 3LD turbo because i dont know how to hook it up the the manifolds thanks for tellin me before i wrecked somethin you guys are a handy bunch

I bought one new in 1983 and it was the worst truck I ever owned and the worst engine ! Those were no good from the get go.

I've got over 20 trucks, Suburbans, and Blazers with 6.2s. My longest runner was in my 3/4 ton 4WD 87 Suburban that pulled a small livestock trailer and lasted to 520,000 miles before it blew to pieces.

Here are a few things to keep in mind.

The 6.2 was designed originally to have the same horsepower and torque as the 305 gas engine, and not meant to handle much more. All 6.2s and 6.5s have cast-iron cranks, not forged steel like most other diesels.

In 85, a 1/2 ton C-code engine has weaker heads more prone to cracking than the 3/4 ton. The 3/4 ton J-code engine has smaller valves, leaving more metal in head for strength.

If you add a turbo, a 6.2 cannot handle any more than 10 PSI max. Block is too light/weak and compression ratio too high.

Strongest 6.2 made was in 92 when the 6.2 and 6.5 shared the same block, casting # 10149599. The most common and weakest are the earlier # 14022660 blocks with one possible exception. First year model-year 1982 blocks sometimes have better metal with more nickel in the casting.

Block numbers:
1982-1991 14022660 6.2s only
1992 - 10149599 may be either 6.2 or 6.5 as the block was produced during the
changeover from 6.2 to 6.5 by GM.

6.5 only - 12552929, 10237141, 12555506.

An 85 with those miles might be fine, but it's likely the block is already cracked. Many are cracked by 150K, and those cracks gradually get worse over time with no warnings or symptons. Then, all of a sudden, the engine blows to pieces when the crank snaps into several pieces.

My suggestion is (if you want to run a turbo). Pull the oil pan and check the main bearing webs for cracks. If not, fine. If they are cracked at all, forget it - it's a time bomb waiting to go off. If you don't find cracks, you might want to buy a stud-girdle kit that is made for 6.2s to prolong block life.

GM did not fix the crack problem until 1997 when only 6.5s were being made. They finally made the outside main-bearing bolts smaller - 12 mmm down to 10 mm to eliminate block cracking.