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diesel to gas swap

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by seslick77, Jan 27, 2002.

  1. seslick77

    seslick77 1/2 ton status

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    Anybody swapped a gas motor into a blazer? Got a 82 Blazer with 6.2and auto tranny....wanna swap in a 350 because the diesel is shot. Need tips and most importantly, will it meet emission laws in El Paso county Colorado? Would hate to do it and find out that i cant do it and pass emissions!! Will they give me any crap if Im running a gas motor in a deisel truck when they run the VIN? Any help or ideas would be appreciated! Thanks
     
  2. dyeager535

    dyeager535 1 ton status Premium Member

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    *in my state* (WA) it is legal to do the swap, as long as everything from the gas motor is brought over. Stupid things like gas gauge (unleaded only) and sticker on fuel filler door have to changed, then it had to be re-inspected. I'd call the local DMV or whoever handles that stuff in your area, and see how it has to be done, or if its even possible.

    Dorian
    My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
    Why insist on counting when the ring gear has the tooth counts stamped in?
     
  3. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    I've done the swap (CUCV K30 to TBI 350) so I'll be glad to help if you have questions. Do a search, I've posted some rather long replies on this a month or so ago. Pete (pcorssmit) has also done it and was a HUGE help when I was working my way through. There are also others here than will be able to help with any question that may come up.

    As for CO laws, no clue. We've got many CO members though (including Pete) who can probably answer your questions on that.

    Russ

    85 K30 CUCV, 350 TBI, TH400, 205, D60/C14, 4.56 Locked, 4" lift, 42" tires
    Some day: massive cutting, shorter wb and rear overhang.
     
  4. seslick77

    seslick77 1/2 ton status

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    Hey appreciate the help you guys are willing to give!! Trust me I will be asking A LOT of questions when I get ready to do this. Will be callin the DMV first thing tomorrow and asking about it. New to this emisions crap, moved here from KS, never had to worry bout it there!! Just got the truck this week, new about the problem when I bought it. Guy says he drove it to the mech. after he noticed a huge power loss. Mech. says 3 cyls. low compression. barely does 30mph right now!! I know nothing bout diesels, that is why I am considering the swap to something I know more about.
     
  5. Rix_Gotta_Blazer

    Rix_Gotta_Blazer 1/2 ton status

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    i have heard that you can take a 6.5 diesel and swap it out with a Oldsmobile 350. apparently, you can use the same motor mounts. tranny is another story. i could be full of doo doo, but i believe i have heard that before.

    i liked this bumper sticker i saw, "real Americans DRIVE American"
     
  6. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Complete Chevy big block and small block (with accessories) are both a direct bolt in replacement for the 6.2 and 6.5 Diesel. Main pain is wiring, cooling, and fuel system changes, and they are not that big a deal as long as you get the stuff from the donor vehicle. A true Olds 350 is much more trouble.

    Russ

    85 K30 CUCV, 350 TBI, TH400, 205, D60/C14, 4.56 Locked, 4" lift, 42" tires
    Some day: massive cutting, shorter wb and rear overhang.
     
  7. pcorssmit

    pcorssmit 1/2 ton status

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    The 350 Olds swap would require custom motor mounts (or ones from a '79-'81 C10 w/a 350 Olds diesel) and either an adapter or a tranny with the BOP bellhousing. A 350 Chevy, on the other hand, is a bolt-in (internal tranny mods and torque converter recommended, though).

    Does El Paso county have emissions testing on diesels? If not, you're in like Flynn, just don't tell anyone and you're set.

    If you are in the enhanced emmisisons area (front range), like Denver, you have to get the truck recertified since they require emissions tests for diesels. Basically, you have to have the emissions equiptment for the donor truck. Car engines and emmisions are OK, as are LD emissions truck engines. HD emissions truck engines are a no-no. However, they will never run the #s on the block. Either get the correct emissions stuff for your year and swap in something that looks like a 350, or get the stuff from a newer truck. I had no probs with the diesel fuel gage, but did have to add a cat (they gave me a waver for dual cats since it was a factory dual exhast truck, but I went single anyway), fuel tank restrictor (buy a repair kit at Checker for like $8, problem solved), evap canister, etc. I put in an '87 TBI motor. There really is very little smog stuff on top of what is needed for the motor to run right anyway. Of course, (if in the enhanced area where they dyno test gas) you could just cap the evap canister lines and put in the canister and the cat every 2 years at emissions time. Also, if your setup uses a check engine light, it must say "check engine" or "service engine soon". Again, pretty simple. BTW the certification people here in Denver are actally pretty helpful.

    Pete

    '83 K5, 350 TBI (ex 6.2), 700R4, NP208, Dana 60/14 bolt, 4.56s, Detroits, 3" lift, 15-39.5x15 TSLs
    '97 Dodge 2500 4x4 CC LB Sport, Cummins 5 spd
     
  8. DieselDan

    DieselDan 1/2 ton status

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    Hey Sea, Just to play devil advocate; Was the mechanic who said it was low on compression a "diesel" mechanic? Did he tell you what the actual pressures were? How many miles are on the 6.2? Are you laying down a smoke screen (blue, white, black?)? The reason I ask is because most regular garages are NOT equipped to test a diesel (need a high compression guage and a glow plug adapter).

    PS Never mention Olds diesel in the same breath as 6.2/6.5 GM diesel!

    Real trucks don't have spark plugs!
     
  9. seslick77

    seslick77 1/2 ton status

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    Hey great info fellas!! I talked to the emissions tech and he told me the same thing you said, air pump, cat. converter, gas flapper thing, etc. Said when I get it done gotta go to a state emissions center to get it certified. And yes they test diesels here, damn!! Sounds easier than I thought emissions whise. Found a 350 from a friend of mine for 50 bucks, gonna attempt a rebuild on it.....Fuel system should be no prob. just run new lines, new junkyard tank and filler neck, and pump. So I can't use my diesel radiator? And wiring...uhhh help lol! Are you talkin full harness or what? Hope not....expensive!! Anyway, I figure, this is a really good idea, I mean this truck is in really nice condition...except motor, everything works like new! Power windows are a little slow but easy fix. Got the truck CHEAP too!

    Oh, about the Mech..... not sure if he was a diesel shop or not would have to check with the guy i bought it from...he told me "3 cyl. low comp. visible blueing" if u can figure that out...I dont know anything about diesels. Thought about a rebuild on the diesel, but kits are very$$$$$$$$$$$$$$$!!! Trying to make this an easy budget rebuild!! Keep the ideas rollin in!! I appritiate it!!

    Sam
     
  10. dyeager535

    dyeager535 1 ton status Premium Member

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    &lt;Fuel system should be no prob. just run new lines, new junkyard tank and filler neck, and pump.&gt;&gt;

    Not sure you'll need new lines, since I believe the diesels used mechanical pumps anyways. Tanks also shouldn't be different (enough anyways) to worry about, but the fill necks (piece that the gas pump nozzle fits in) are different. Have to match late fill necks to late sending units, and early fill necks to early sending units. When GM went to the "restricted" fuel necks, the diameter of the hose to the tank changed.

    Actually, just check and see if a gas fill neck is compatible with the diesel sending unit fitting. My '81 gas sending unit, and '86 Diesel fill neck, were not compatible, although I did pull one out of a late 70's that did work. The fuel hose diameter DID change, but I can't remember for certain whether both ends changed size, or just the fill neck size. I also couldn't find the hose that connects the fill neck and tank, I had to get a used one.

    &lt;&lt;So I can't use my diesel radiator?&gt;&gt;

    Not sure why you can't, you'll just have extra oil cooling fittings to plug.

    &lt;&lt; And wiring...uhhh help lol! Are you talkin full harness or what? Hope not....expensive!!&gt;&gt;

    Can't comment on engine bay wiring, since mine was cut, but the internal harness had the wait light and water in fuel light wired in. It too was cut in a few spots, so I swapped it as well. Easy since the interior was bare, much more of a job with everything in place. I'd have to think the absolute easiest way to swap everything is to find a like year truck with harness intact, and use it. Barring that, I'm sure with work, the existing harness could be made to work. FWIW, the engine bay harness is very easy to disconnect and change wire locations on.

    &lt;&lt;Got the truck CHEAP too! &gt;&gt;

    Cheap is good : )


    Dorian
    My tech/links page: &lt;a target="_blank" href=http://www.dorianyeager.com/index2.html&gt;www.dorianyeager.com/index2.html&lt;/a&gt;
    Why insist on counting when the ring gear has the tooth counts stamped in?<P ID="edit"><FONT class="small">Edited by dyeager535 on 01/29/02 03:54 PM.</FONT></P>
     
  11. DieselDan

    DieselDan 1/2 ton status

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    Try <a target="_blank" href=http://www.naparts.com>www.naparts.com</a> Northern Auto Parts for CHEAP engine rebuild kits. THE cheapest for 6.2 diesels. How many miles on that puppy?

    Real trucks don't have spark plugs!
     
  12. pcorssmit

    pcorssmit 1/2 ton status

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    (not responding to Dorian, just looking at his post)

    If you want to try the diesel at all, change the fuel filters, and maybe check the pressure on the low pressure side of the fuel system. Pretty cheap, and probably at least worth a shot. Even if you still pull the diesel, 6.2s are worth some decent $ if they run, even if they run like crap, but the better it runs the more its worth.

    IF you're running a carb'd motor,
    You don't need a new tank, lines, or filler neck. Flush the old system. For the filler neck, all you have to do is buy the repair kit I told you about in my previous post. The diesel fill necks have a ring that it seats on. I put one in mine (OE '83 fill neck w/swapped in '87 EFI tank). The diesel sending unit should work fine (as I recall, the sending unit has nothing to do with the filler anyway). If you want, you can remove the WIF sensor and related wiring. Remove or plug the return line, or you may be able to reroute it for the evap canister (depending on how its supposed to be, I don't know for a carb'd truck).

    You can use the diesel radiator, but the upper hose will most likely have to be a two piece (one diesel and one gas, spliced together). I used one off a '72 Firebird w/400 motor and stretched the end, but others on the board haven't had luck with this. You can use the oil cooler w/manifolds (have to get a cooler adapter for a gas motor), but w/my headers it won't work. The bottom isn't as bad, a gas hose fits good enough.

    Should be pretty easy to get the wiring going. Use the diesel oil sender (otherwise the gauge will be off). Should be able to run the big pink wire right to the distributor. Not sure what else you'd need, just rip out the rest of the stuff. The low coolant wire can stay (or go if you don't want it).

    Pete

    '83 K5, 350 TBI (ex 6.2), 700R4, NP208, Dana 60/14 bolt, 4.56s, Detroits, 3" lift, 15-39.5x15 TSLs
    '97 Dodge 2500 4x4 CC LB Sport, Cummins 5 spd
     
  13. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Sounds like everyone has pretty much got you covered. Can't help much on the harness except to say that I switched mine from the donor. I got the engine harness, computer harness (mine was TBI), and dash harness. I didn't have much choice, I wanted to ditch all the military hybrid 12V/24V stuff. If your running a carbureted engine with mechanical fuel pump, just use the diesel tank and put the unleaded "repair" kit into the filler. Heck, I used the diesel tank and modified a FI sending unit (with fuel pump) to fit. Good luck getting rid of the diesel that is in it, I've still got almost 10 gallons that I use for cleaning parts.

    You can use the diesel radiator. The bottom hose for the gas burner will fit just fine but you will have some issues with the upper hose. It seems that some diesel radiators have small necks (for the hose) on top, and some have a larger size. Mine has the small neck, which is the right size for the gas burner hoses, but it is about 6" too far over. I tried to use the same hose that Pete used but had no luck. My water neck on the intake was pointed the wrong way and it just wouldn't work. I wound up using the formed hose that was correct for the engine I am using. I just cut it where it goes straight across, parallel to the radiator, and inserted a 9" piece of pipe to extend the hose 6" so that it would make up on the radiator. The opening in my diesel fan shroud is also way bigger than the fan on my 350. I just plugged off the oil cooler fittings in the radiator but I am using the factory external oil cooler. I'm also using an external tranny cooler plus the radiator tranny cooler.

    Good luck.

    Russ

    85 K30 CUCV, 350 TBI, TH400, 205, D60/C14, 4.56 Locked, 4" lift, 42" tires
    Some day: massive cutting, shorter wb and rear overhang.
     
  14. pcorssmit

    pcorssmit 1/2 ton status

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    <blockquote><font class="small">In reply to:</font><hr>

    Good luck getting rid of the diesel that is in it, I've still got almost 10 gallons that I use for cleaning parts.

    <hr></blockquote>

    I finally got rid of mine by mixing it 1:1 w/Kerosene and burning it in my reddy heater.

    Pete



    '83 K5, 350 TBI (ex 6.2), 700R4, NP208, Dana 60/14 bolt, 4.56s, Detroits, 3" lift, 15-39.5x15 TSLs
    '97 Dodge 2500 4x4 CC LB Sport, Cummins 5 spd
     
  15. seslick77

    seslick77 1/2 ton status

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    OK, so I guess I'll pull a rad. from a donor from the scrap yard. Is there a readily accessible book or web site that could tell me how to wire this thing up or an original wiring diagram? Doesn't sound too difficult to do, just tedious. So a broke 6.2 is worht some $$ huh? Well that helps to fund this swap then:) As for gettin rid of the old diesel....Ill just dump it in one of the fire trucks at work lol!! Anybody know what tranny this thing got? think it be the th350 but not sure. Saw something about "new 4 speed overdrive 82 model diesels".
     

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