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Engine rebuild

Discussion in '1982-Present GM Diesel' started by 4x4_76, Feb 18, 2002.

  1. 4x4_76

    4x4_76 1/2 ton status

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    So,I have 6.2 disassembled in my garage.First I thought that it only needs new piston-rings and few other parts.Not anything big.Yeah,right,I should've known better.Over-bore,new pistons,new connecting rod bearings,camshaft bearings,valve guides,probably new valves and springs,and so on... Oh well,better do it good first time,so I don't need to pull the engine out after couple of years.

    Couple of questions:

    1.Valve stems were under the specs.Is it possible to machine them down so I could use over-size guides(if available)?Or is it better to buy new valves?

    2.All the valve springs were under the specs that overhaul manual gave(they were shorter,max.about 1.3mm/0.05 inch).Can they be re-used or should I get new ones?

    3.When I took off the pistons/connecting rods,I noticed that one piston had had contact with crankshaft.And only from one side(under the pin).That connecting rod/piston was changed about 13000 miles ago.Previous piston was cracked under the pin.So is the connecting rod bent,or is it possible that connecting rod journal is tapered?

    '80 K5,355/350/205,soon 6.2 diesel swapped in and 33" tires[​IMG]
     
  2. Danno

    Danno 1/2 ton status

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    I'd replace all parts that are under spec with new parts that meet spec. No point in running sub par components in a freshly rebuilt engine. I'm sure you don't want to have to rebuild it again for a long time! ;-)

    When all else fails... <a target="_blank" href=http://www.62-65-dieselpage.com/features/TheDieselDepot.htm>http://www.62-65-dieselpage.com/features/TheDieselDepot.htm</a>

    1984 K5 Blazer 4x4 Silverado
    6.2L diesel, 700R4, 3.42 gears, 31x10.5" tires
     
  3. 4x4_76

    4x4_76 1/2 ton status

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    Ok!So I decided to replace all the valves and the springs.Luckily I found partstore that sells a bit cheaper parts than local store.Cost is about $1400 for parts,plus machining about $360.
    Only thing that worries me is connecting rod,but I guess folks at the machining shop can check it out.

    '80 K5,355/350/205,soon 6.2 diesel swapped in and 33" tires[​IMG]
     
  4. Danno

    Danno 1/2 ton status

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    You should do a write-up of your experiences and estimated (or actual) costs of your rebuild. My engine's got over 200,000 miles on it now, and still runs great, but I'm sure I'll have it for a long time. Eventually, I'll need to rebuild my diesel!

    I'm interested in what you end up going through to get your engine rebuilt.

    1984 K5 Blazer 4x4 Silverado
    6.2L diesel, 700R4, 3.42 gears, 31x10.5" tires
     
  5. carolina custom

    carolina custom 1/2 ton status

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    parts for our diesels are seem to be 2-3 times that of a smalblock. the best price I have found on a rebuild kit is from northern auto parts. I dont remember the price but I belive a kit with pistons, bearings, gaskets, head bolts, and maby timming set is over $1000. I know I paid gm over $300 for rod bearings and over $200 for mains. I needed them fast and got local dealer to order them with out asking price. I was in a bind and had to have them. You will also need new head bolts as they are torque to yeld. The good news is machine work will cost the same as a gasser.

    84k20,18:1- 6.5td,400/208,4.10,5.5",35"s
     
  6. 4x4_76

    4x4_76 1/2 ton status

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    Head bolts are included on my list.I first forgot them,but when I was checking out part-dealers website,there was a comment that new bolts should be used.And they weren't expensive so I replace them,too.

    These are the parts I get:Gasket set,pistons,piston-rings,connecting rod bearings,camshaft bearings,intake and exhaust valves and springs,head bolts.
    Camshaft was ok,timing chain and gears,oil pump and main bearings have been there about 13Kmiles.

    Damn,those were expensive bearings.I can get main and rod bearings for about $200.

    Danno,
    I'm gonna do somekind of website about my project,so there will be engine rebuild also.Takes about month before there is anything,I don't have much time to work on web currently.

    '80 K5,355/350/205,soon 6.2 diesel swapped in and 33" tires[​IMG]
     
  7. Aggro

    Aggro Registered Member

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    Just an idea: When it was time to rebuild my 6.2 I found it was cheaper to buy a rebuilt 6.2 from Boyce equipment in utah. My takeout had roughly 3/16" of crankshaft endplay from it's 260,000 miles of service! Still ran like a top though.

    Junk. It's what I drive.
     
  8. 4x4_76

    4x4_76 1/2 ton status

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    Aggro,

    That's is a good idea,because I'm really pissed![​IMG]I was just cleaning the block and found a crack.And not just one,but five.They we're all by the outer main cap bolt.I've never heard that 6.2 blocks would crack from there.Damn!

    Luckily I found for sale add of a 6.2 engine from Van,170000km driven.I go check it tomorrow.If it's good,I guess I buy it.Cost is less than what all the parts and machining would cost on my disassemled engine.

    '80 K5,355/350/205,soon 6.2 diesel swapped in and 33" tires[​IMG]
     
  9. arveetek

    arveetek 1/2 ton status

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    Unfortunately, main web cracks are too common. It's really the first thing you should check for when rebuilding.

    Luckily, Out of three different 6.2L engines I've had, none have had cracked main webs. But I've heard and read a lot about them.

    On another note, glad you're swapping your gasser out for a diesel. I've done two conversions...one into a '77 Blazer, and the other into an '81 C-20, which I still own, and she is my "baby."

    Hope it all works out for ya!

    Casey


    1986 K-10, 6.2L N/A diesel, SM465, NP208, 3.73 gears
    <a target="_blank" href=http://community.webshots.com/album/14911798DvydoACKJE>My Chevy Photo Album</a>
     
  10. 4x4_76

    4x4_76 1/2 ton status

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    It was a real jackpot that I found the for sale add of that engine.If I would try to find good block here in Finland,it would take long time.So I buy that van engine,put aside that one what is in pieces in garage,and build it later for a spare engine.
    This guy who is selling that engine,said that he has been fixing his friends van so much that he has had enough.So he sells that engine for fairly cheap price.
    Within a month,my Blazer should move with diesel power.[​IMG]

    '80 K5,355/350/205,soon 6.2 diesel swapped in and 33" tires[​IMG]
     
  11. Danno

    Danno 1/2 ton status

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    Most excellent... Welcome to the family of oil burners! :-)

    1984 K5 Blazer 4x4 Silverado
    6.2L diesel, 700R4, 3.42 gears, 31x10.5" tires
     
  12. 4x4_76

    4x4_76 1/2 ton status

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    Thanks!/forums/images/icons/smile.gif
     

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