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reasons for 6.2L being "gutless"

Discussion in 'The Garage' started by Tenpack, Oct 23, 2005.

  1. Tenpack

    Tenpack Registered Member

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    i've dont some searching, but couldnt find a real specific reaons why the 6.2L is gutless. Is it the internals? It a MPG based engine and gives up power because of this? Which years/ models came turbo'd? I've also read off PBB that there was choice block years, and the main ones where 82 and 84; could someone tell me if these are right? I've read that you can get more power by doing the intake and straight pipe exhaust and going 1/6th of a turn on the fuel pump, how accurate/safe is this? Im looking to get a '86 burb with the 6.2 and wanted to know some stuff bout it. It will serve as mild tow rig, mainly DD and weekend wheeler. Thanks guys :burb:
     
  2. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    Most of the problem is horrible gearing. With decent gearing they are no worse than many stock 305's and 350's i've driven. They are mpg based though, and IMO not really suited to towing anything heavy. They'll do the job, but it'll take forever. Light to moderate towing should be fine though.

    I port matched my intake and felt it helped somewhat. Every bit co8unts and it was a nearly free mod. The factory casting was horrible on the intake I did...I ended up opening each port by over 25% and then blending.

    I've heard the early blocks are somewhat better, but how much better I'm not sure. My 6.2 is an '85.

    You can turn the fuel rate up a little bit, apparently it does make a good difference although it won't help your fuel mileage any. I haven't touched my fuel rate yet.

    That burb will have the 700R-4 if it's half ton, and the TH400 if it's 3/4 ton. I'd 'hope' it's a 3/4 ton as it'll have the more powerful 'J' code 6.2 and much better gearing (4.10's) The 1/2 ton would have gears as bad as 3.08's with that OD tranny...as well as a somewhat choked off 'C' code 6.2.

    Rene
     
  3. Tenpack

    Tenpack Registered Member

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    yes, it is a 3/4t, otherwise i wouldnt touch it. I've seen how durable 10 bolts are... :rolleyes: It's the trailer pacakge.

    I havent found much aftermarket for them... DO you know of any companies that make aftermarket parts for the engine? Also, I'm assuming its a np208 in it? Thanks guys
     
  4. 6.2puller

    6.2puller 1/2 ton status

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    Gutless is a relative term. They can't hold a candle to a 7.3 Ford or a cummings diesel but I will take mine over my 350 anyday. It is probably halfway between my carbed 350 and TBI 454 in power seat of your pants style.

    You can open up the exhaust but I didn't feel much difference when I went to dual 2" with flowmasters. Ran it with no mufflers and other than the sound getting higher pitch than the flows it didn't change power feel.

    I turned the injection pump up 1/4 turn and put the EGTs about as high as I dare on long highway hills with the trailer. That gave me the most power of anything I have tried so far.

    I just purchased a J code (non EGR vin code) intake and have to install that. That is supposed to really free up the intake end of things if combined with a little grinding to match the intake of the head.

    Gearing is also important. Mine came stock with some high 2.?? gears. I didn't hit overdrive until 75mph and over here in New England we don't have highways over 65mph so..... I swapped in a 14 bolt with 4.10 and that helped alot. Specially when starting up on a hill with the trailer. 4.10 are probably a bit tall if you run over 65mph a lot but they seem fine for my 65 top speed.

    And last but not least check the diesel forum for true experience stories of the 6.2 because most people that run their mouths about them have never even driven one. Most of the issues people bring up about them are actually about the old 5.7 olds diesel from Pre 82 and those aren't even the same block or manufacturer.
     
  5. 6.2puller

    6.2puller 1/2 ton status

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    Not many parts made. They haven't made this motor in the regullar truck line in over 10 yrs so the aftermarket is small at best.

    By the way their were no factory turbo units as you asked in your first post.
     
  6. Tenpack

    Tenpack Registered Member

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    mhmm, cause i'm sure a big difference between the PSD's and CTD of that era was teh turbos. What are they J Codes you speak of? A chip that you install? Thanks for the patience guys
     
  7. micah

    micah 1/2 ton status

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    I'm no expert, but the J code he is referring to is the desirable intake for the 6.2.
     
  8. 6.2puller

    6.2puller 1/2 ton status

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    Yah, its the vin code for the 6.2. A C code is the emissions motor and the J code is a non egr motor. The J code is more open and free flowing.
     
  9. Robert79K5

    Robert79K5 1/2 ton status

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    I agree about gutless being a relative term. No its not a Cummins but if the fuel system is working properly and its allowed to breath they can make some respectable power, especially if you give them a little forced induction, and yes I would say they are biased towards economy. That was one of the concerns while this engine was being designed. I had one in a c10 with a 700r4 and 3.08 gears I think, and while it never pulled anything very fast you couldn't stop it either, it would just keep pulling harder as I depressed the accelerator. I hauled some serious loads with that truck.

    I honestly think that the 6.2/6.5 is the optimal diesel for a trail vehicle. For a diesel its light, lighter than a cummins or powerstroke, its simple and economical, no real special tools required to work on the actual engine, and it can rev pretty high and fast for a diesel for when you need to turn some RPMs. Out on the trail I would much rather have a 6.2 hanging over my front axle than a Cummins 6bt.
     
  10. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    'J' code:


    [​IMG]

    No EGR crap at the inlet area so it flows a ton more air.

    My Dad used to have an '86 Ford F350 with the NA 6.9 and it had about the same power as my 6.2. A turbo really makes a huge difference, and it's somewhat easy to swap on 6.5 TD parts or use the Banks sidewinder kit.

    The sidewinder kit will get you ~450 lbs of tq to the rear wheels...

    Rene
     
  11. Tenpack

    Tenpack Registered Member

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    thanks for all the info. What were the factory numbers? Any aftermarket 6.2L manifolds? ebay has turned up nil.
     
  12. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    Well, that 3/4 ton Sub would already have a 'J' code manifold...

    Factory numbers vary by source, but the advertised numbers are 155 and 265 for the 'J' code. I've seen chassis dyno numbers in the 135 RWHP and 340 lbs RWTQ though.

    Best to drive it and see for yourself. I've always been quite happy with mine and haven't done much of anything to it. Mine turns 39.5" TSL's too...

    Rene
     
  13. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    There was no PSD or Cummins Dodges around in the earlier 6.2 days. There were no turbo'd diesel pickups until the late 80's IIRC. Just the 6.2 GM and the 6.9 Ford.

    There is no chips on the 6.2, they are a very simple mechanical motor. I think it's a good engine. A little underpowered stock but a good reliable engine. I'd buy the burb.

    Also, you mentioned in your original post about freeing up the intake and strait piping one. I think you are thinking more of the newer diesels. With the lack of a turbo a strait piped 6.2 would be WAY to loud to be legal, and not help much at all. :doah:

    Good luck on the purchase, You'll probably like the engine.
     
  14. 89GMCSuburban

    89GMCSuburban 1/2 ton status

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    Turbo kit for 6.2

    There's the sidewinder kit. GM actually offered it from the factory as an option.
     
  15. ZooMad75

    ZooMad75 1/2 ton status Premium Member GMOTM Winner

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    A couple of buddies of mine are in the process of swapping a 6.2 for a 6.5 in a 86 suburban.....For those who don't think the 6.5 is no longer made or has not for the last 10 years is wrong.....AM General (the Hummer guys) bought the rights to the engine and the tooling around the same time the D-max was coming out..All the mil-spec hummers have the 6.5 (or older ones had the 6.2) so it made sense for them to keep building the engine. Workhorse Custom chassis used the 6.5 up to the 2005 model year and besides the obvious H1's and military humvees they sell into the marine industry too...
     
  16. Tenpack

    Tenpack Registered Member

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    But how much does it cost?
     
  17. 89GMCSuburban

    89GMCSuburban 1/2 ton status

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    Couple of grand, I believe. Just tossing in all options.
     
  18. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    You can piece together something similar for a lot less. eBay has turbo's and other parts all the time.


    Rene
     
  19. eclipse

    eclipse 1/2 ton status

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    I have a '82 1/2ton Burb with the 6.2 and 700r4. Its bone stock with 3.08 gears and 31" tires. Its not a bad driver, I drive it to work and on the highway. I dont expect to get anywhere fast, or pass. Its got 100k on its rebuild. I know its the C code cause I've seen the EGR valve on the manifold. I've always wanted to put a 4" lift and 33s. I figured I'd have to put atleast 3.73s to run 33s on with the 6.2. I thought it would be nice to put a turbo on it, but it seems pretty tired and I thought banks recommended low miles or a rebuild before adding a turbo.
     
  20. 6.2puller

    6.2puller 1/2 ton status

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    Which is exactly why I specified that they haven't made the 6.2 in the regular truck line in over 10 yrs. I am fully aware they are still being used (or were until just recently) by the millitary and the marine applications.
     

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