GM 6.2l diesel engines

Greg said:
After looking into 6.5's, in order to make a more reliable engine there are several key upgrades that need to be preformed. Head studs as mentioned, balancing the rotating assembly is a great idea, adding a Fluidampr harmonic balancer is a good idea, a web cradle for the bottom end is recommended, etc. Each of these mods run between $150-300+ and in the end, you'd have to totally tear down the motor and pretty much build it from the block, up. You would be into the rebuild a bare minimum of $1,500.

In the end, you still have a cast crank that is known to break, a block that is known to crack, a problematic glow plug system and a very limited amount of power that you can safely squeeze out of the motor.

So to sum it all up, for the cost to build a 6.5l, I think I would be better off with a Cummins 6BT. :greg:
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I was pretty sure the cranks were steel and quite stout. It has been a popular consensus that the problematic harmonic balancer is what leads to crank falure and for good reason. Rubber was used to deal with the shock loads, but in the long run the rubber rots out and throws the crank off balance. It has been said that the trucks with manual transmissions suffer from this the most along with premature timing chain wear. I've seen it a lot in either though :-\ The fluidampr has proven to be a major upgrade.

Certain years of blocks were known to crack--some worse than others and some not at all ever. I would bet money that 95% of block in 97 trucks ending up in catastrophic failure with less than 100K miles if that. The 92-93's were good as were the 99-00 and 01-current AM General blocks being the best.

Either way if you are into a 6.5 far enough to have the crank polished you may as well add the lower compression pistons. Greg did you read the "More Power" article on the diesel page? 300+hp is a lot in my book and it really didn't take an awful lot of money. I've seen a few low compression 6.5's and they rip! For being an old 2valve IDI anyway...

Either way it all costs money in the long run and its really hard to argue the greatness of the Cummins. I went from a 6.5 to the 5.9 and I will never look back. Just my .02 :-\ Will it fit in an 80 though? 1100 lbs is a lot of weight for a Toyota axle to support. Oh the power... I'd go VE pump 12v for big reliable power with the best mileage. Sorry just thinking out loud again :o
 
gravesdiggerxj said:
Rot Box:
I just got a 94' 6.5 turbo diesel suburban,

what should I do to it to make it more reliable and make a little more power/mileage?
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1. Don't EVER let it get hot. 217* has proven to crack the heads--that's just past strait up and down on the temp gage :ugh:

2. PMD (pump mounted driver) isolator. The pmd CANNOT be anywhere in the engine bay no matter how difficult it may be to move it. You can't easily gain access to it so its best to just buy a new one. This is the only kit i would consider http://www.heathdiesel.com/T/Chevy-GM/Chevy-9495/PMD-Isolators/ I built a wiring harness and custom heat sink for mine and put it behind the front bumper. It dropped 100* in operating temperature a eliminated my trucks habit of stalling (in the middle of heavy traffic) and not starting.

3. Lift pump. The pumps are typically pretty reliable but the OPS (oil pressure switch) that controls them is known to fail. It is mounted in a pita location on the back of the intake manifold. It cuts fuel to the injector pump if there is no oil pressure. The engine will run without the fuel/lift pump but it will cut out and not start easily. It also starves the IP which can lead to problems there. http://www.heathdiesel.com/T/Chevy-GM/Chevy-9495/Lift-Pumps/

4. If you work it at all get the 96.5-00 cooling upgrades. They include a high flow dual t-stat housing and a higher gpm water pump. These are mandatory if you work it even a little bit.

5. Easy power includes intake and exhaust. An aftermarket downpipe is a big improvement over the pinched stock one. Run at least 3" from the turbo to the tail pipe. An easy intake mode is to remove the tube between the airbox and the fender. This will flow as much air as any aftermarket intake. Use a stock paper filter ask me how I know! :ugh: These two mods make a huge difference on the 6.5. Next would be a #9 calibrator resistor for the injector pump. The #7 is included with the PMD isolator, but I would run a #9 for even more fuel delivery--very easy to install.

6. At this point you must have guages for boost, pyro and trans temp.

7. Join the www.dieselpage.com website. It and the books they offer are a MUST for any 6.5 owner. These guy's saved me more money than I can count when it came to fixing issues that are easily mis-diagnosed.

Hope this helps. They can be really great or a total nightmare depending on what you do for preventative maintenance. With just these modifications you will walk all over any stock or slightly modified TBI 454 I will guarantee that.
 
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VE's are WAY cheaper to replace, they're a proven design dating back to at least the early 60's, very reliable, etc. All the big power guys want P-pumps, which has driven their cost up, as well. And like the man said, the VE motors are known for reliable mileage more than anything else. :D
 
bryson said:
Not a P-pump engine?:eek2: How come?
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Tacoma said:
VE's are WAY cheaper to replace, they're a proven design dating back to at least the early 60's, very reliable, etc. All the big power guys want P-pumps, which has driven their cost up, as well. And like the man said, the VE motors are known for reliable mileage more than anything else. :D
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sixb said:
VE = dynamic/variable timing, enough said.
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Tacoma and sixb nailed it. Not to mention a first gen donor truck can be had for under 2K. For these reasons I think they are the best 5.9 option for a swap like this.
 
Wow, real interested to see how this project goes. Carl, I think that was a different motor. That was a poor GM attempt at turning a 350 into an oil burner. Never did work. My x FIL had one in a Buick. Not good.
 
Bart said:
That was a poor GM attempt at turning a 350 into an oil burner.
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They also made an attempt at turning the 4.3 v6 into a diesel. I met a guy that had one in a BossHoss motorcycle chassis. Had that idea been successful at all it would make one awesome Toyota mini truck swap :D
 
Soooooo bringing back the dead. As you probably read in my other post my brother found a clean locked 94 Toyota FZJ80 awhile back for what seemed like a screaming deal at the time. Turns out the motor has some issues and needs replacing...

Last night he drove home a good running 83 K2500 4x4 with the red block 6.2 diesel and 700R4. I also noticed the hood on the LC was up long into the night :eek2:




Oh boy :eek2:
 
Rot Box said:
Soooooo bringing back the dead. As you probably read in my other post my brother found a clean locked 94 Toyota FZJ80 awhile back for what seemed like a screaming deal at the time. Turns out the motor has some issues and needs replacing...

Last night he drove home a good running 83 K2500 4x4 with the red block 6.2 diesel and 700R4. I also noticed the hood on the LC was up long into the night :eek2:




Oh boy :eek2:
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The 6.5l diesel swap in a Land Cruiser is HUGELY popular in AU, they love that engine down there! I think a good running 6.2 and 700R4 would be killer in a 80 Series, a turbo would make it better but plenty of torque and killer MPG's. I'd love to hear how this turns out.
 
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