Home » Featured »Project Cars »Tech » Currently Reading:

Proposing Project Smokeyvette: eBay-Sourced Diesel C3 Corvette Commuter

Tim Odell October 4, 2012 Featured, Project Cars, Tech 50 Comments

As my online handle “Mad_Science” might suggest, I have some experience with the world of science and research (I once had a remote control rabbit). Funny thing about research: you can’t sell it. Well, not in the traditional sense. With a conventional product or service, the buyer pays upon delivery. In the case of research, it’s really the opposite. They pay you… and you receive a report, or something, eventually. With that in mind, we’re kicking off a series of Project Proposals. We’ll propose some cockamamie scheme, then take the next step and show you just how you could get it done.

To get things rolling I propose we grab a clapped out C3 Corvette, drop in a 6.2 or 6.5L Detroit Diesel and turn it into a great long-haul commuter. The crazy part is how one can use GM parts bin engineering to make it surprisingly easy. Let’s see what it takes to make Project Smokeyvette a reality…

[Disclaimer: eBay approached us about writing posts on how you could buy a project car and fix it up using stuff purchased through eBay Motors. Crazy, we know. We’re still looking for someone who’ll pay us to drink beer or eat burritos.]

Why bother with this at all? The idea was born from my previous commute: 41 miles of full-speed reverse commute in Los Angeles. While my WRX and Falcon worked just fine for the job, the idea of a purpose-built commuter that wasn’t some tiny dorkmobile was very attractive. “Reasonable_Science” would probably just run out and pick up a , but where’s the fun in that? Let’s see if we can’t find something more fittingly unique.

The ’69-’82 can be called a number of things, but “dorkmobile” isn’t one. It took nearly two decades, but the styling’s grown on me. The best part is that they are widely regarded as the worst Corvettes ever, most critically by Corvette aficionados. Stripped of their Quaaludes at the roller-disco context, they’re a decent platform from which to create a shapely cruiser.

The C3 arguably best personifies the Malaise Era, declining from a late-60s high point of style and horsepower to a 165hp plasticized parody. This is to say, no one’s going to shed a tear when we rip out that smog-choked big block and drop in an oil-burner. With no pretense as a serious corner carver, we’ll free ourselves of gnarly suspension upgrades save just getting things fixed. The end goal is a comfy, stylish commuter getting in around 40mpg.

With that in mind, let’s go shopping. In California, 1975-and-older vehicles are smog-exempt (later if were to pass), so we can start our search there. The best candidate would be clean-bodied with a blown motor, but since this is Redusernab we’re just looking for the cheapest serviceable example. Numbers matching is for Sesame Street viewers. We’ve come up with a couple of options:

If we pretend for a second that California SB 1224 passed (moving smog test exemption up to 1980), this ’77 makes a lot of sense. It’s a more-or-less intact shell with handsomely faded blue paint. Whether or not glass comes with the car is unclear, but for $225 (with no reserve) as of this writing, we can afford to replace it all.

In significantly less hopeless condition we have a ’69 with a new interior and paint, but no motor. Ok, I lied; it’s actually got two motors: a boring GM Goodwrench 350 and the (presumably dead) 350. Neither is installed, so let’s just unload them and fatten our project wallet. At a little over $3,000 with the reserve unmet, it could get pricey…but it’s probably worth avoiding yourself.

This ’72 has been sitting for 10 years with a shot 454 (water in oil) and an exterior appearance that’s decidedly not HOA compatible. It does come with a four speed and updated suspension bits. It’s got 100k on the odometer and a $4,500 price tag as of this writing. We’ll call her “Hoonilocks.”

Following up on that, it’s motor time. The were designed in a fuel-crisis scarred era to focus on efficiency, not crazy power. In a military CUCV the 6.2 , so imagine what it can do with 1500lbs less weight and no Duplo aerodynamics. While a turbo 6.5 would pack a better punch, a normally aspirated 6.5 will give us a bump over the 6.2 but keep the engine compartment less cramped and hot. This example is a complete “drop in and go” from a ’91 one-ton GM Van that was running as of yesterday. Not bad for a $1950 asking price.

To get the most of our miserly diesel, we need to keep the revs low. The first step is an overdrive transmission, specifically the heavy-duty 4L80e already found behind numerous oil-burners. Depending on your risk tolerance and faith in GM powertrains, you could pick between this re-manufactured unit for $1,605/1,790 (start/Buy-it-Now):

Or this $895, 6-month warrantied, 95k mile used example from a totaled van:

Since our Corvettes date from an era where computer was defined as “one who computes”, we’ll need to pick up a stand-alone transmission controller. This unit from TCI Automotive does the job for $558.88:

The overdrive automatic gets us a long ways there, but we need that diesel lump chugging at roughly 1800rpm for best efficiency. Pluggin the .75:1 overdrive of the 4l80e and a set of roughly 27″ tall 225/70 R15 tires into the Vexer Gearing/tire size calculator, a set of 2.72:1 ring and pinion gears to get in the sweet spot. Unfortunately all we can find are 3.08:1s, either for $400 new:

or $99.99:

If we bump up to a set of 235/70 R15 Radial T/As, we’re just a notch over 2,000 rpm at 75 mph. $150 each:

Adding it all up and ignoring the minor details, you’re looking at $4-$5k in upgrades to a roughly $4-5k car. Depending on how much gets DIYed, you’d be realistically looking at $15-20k to make Project Smokeyvette a success. There’s something satisfying about the idea of showing up to a Corvette meet in a rough-looking, smokey, clattering example of Detroit’s decline, preferably smelling of french fries. Would you hoons dedicate valuable research dollars to such an endeavor?

This post is part of eBay Finders, a new partnership that presents collections of items curated by a carefully selected group of motors experts. Meet more of the Finders at . #eBayFinders

  • bhtooefr

    The problem is that the 6.2 and 6.5 are not what I'd call good engines.

    Low on power in non-turbo form, and unreliable (and STILL low on power) in non-turbo form.

    Getting far into heretic territory, and not as bolt-in… combine Reasonable_Science and Madder_Science. Jeg's sells a bellhousing that lets any VW watercooled (the VR engines need another adapter found on European B5 Passat VR5s) bolt up to a GM-application T5 (such as one found in the S10).

    Then, pick your engine, there's plenty to choose from. 1Z, AHU, and ALH engine codes are the cheapest and most common, but a 1.9 liter is kinda wrong in a 'vette (but it can be tuned to have enough power). The 3.0 V6s are available here, although have fun with engine management. The 2.5 V6 would be an interesting import, and engine management can be anything that can run a VP44 Cummins (because the 2.5 V6 uses a VP44), but I'd recommend getting one made in 2003-10 or later, when they went to roller-rocker heads – the flat tappet heads eat cams like crazy. The V8s, engine management will be like the 3.0 V6. The 5.0 V10, that would be damn fun, but engine management is absolutely insane (it's treated as two separate 5-cylinders with the second bank's ECU slaved to the first).

    Sure, it's not partsbin, but at least you're using a decent engine then. (It's a damn shame that 4.5 Duramax never came out, though.)

    • You got any idea on prices… let's stick to the 2.5.

      • bhtooefr

        The big problem is that a 2.5 will be an import from Europe.

        I think you'd be in the $3000 ballpark to get the engine, computer, wiring, and ancillaries. You might look at SVTWEB and caddytd's 2.5 V6 TDI swaps (they're on TDIClub), and they got a lot more with their stuff (basically everything diesel-specific from their donor cars, because they were swapping into a gas version of the same car as the donor car). That said… … is quite a bit cheaper than that. But, I think AKE is one of the flat tappet head engines.

        The other question is… how do you feel about a 5-cylinder? A couple options there, a 2.4 non-turbo IDI that could be turboed (and is available in Canada), a 2.5 TDI on the same engine architecture, and a later 2.5 TDI with an aluminum block and gear driven camshafts. Oh, and that early architecture can take some absolutely insane mods.

    • skitter

      I like this idea even better. The VW engine should be lighter, and more tolerable at sustained 2,000 RPM cruising than the Detroits,

  • I still like my oft-quoted idea of a 6.5L GM diesel in a Jag XJS much, much more.

    • Can I +1 this one more time please…

  • racer193

    Why not a V-M motori (is that how its spelled) 3.0 found in the jeep liberty or grand cherokee. Mated to a six speed tremec. with the right tune and gearing it should have no problem ataining 35-40 mpg. switch the tune and have a entertaining sporty(ish) car that would still get 25-30 mpg.

    • Battles

      Definite +1 for the Jeep diseasle. Didn't know you got that in 'Merica?

  • Arco

    Do it, but with junkyard parts. Far cheaper, and more interesting for your readers to look at the junkyard parts process. I see no reason this should have to cost so much. Utilizing a pick-your-part type place your major powertrain components should total less than $500.

    Watch out for those main bearing web cracks though…

  • mr. mzs zsm msz esq

    The buddy I named my dog after figured-out a way to have people pay for his beer online:

    How does the newer engine in older car affect CA smog? Does diesel affect that? In IL we are lucky, if it's a diesel engine, it's never checked. Otherwise if the car is '68 or newer, it gets complicated by many particulars.

    • wow… that man is brilliant.

    • Diesel title = free for all*
      *though some newer ones are going to be subject to emissions testing at some point

      Older that '76 = free for all

      Newer than '76 = newer year engine is acceptable, but you need to include all the newer emissions stuff. Engine also has to be from same "class" of vehicle, but I've never quite figured out what the classes are. I'd assume they'd prohibit a >8500 GVWR motor in a compact car, though.

      Of interest to me are the GM Performance Parts e-rod motors. Theyr'e complete crate motor setups that are pre-approved for use in any pre-'96 (pre-OBDII) vehicle. The're really expensive though, like $8k.

      • 1998 and up diesels started having to get tested a couple years ago. In fact, my mom's '02 Jetta TDI is already due for its second ever smog check this month.

        And yeah, the eRod crate motors are obscenely expensive, and don't even include stuff like front accessory drive or wiring harness. And even then you'll still have to buy a transmission (and controller if you want an electronically-controlled automatic). You'd almost certainly be money ahead to buy a wrecked '98-'02 F-body or '04-'06 GTO complete from Copart or someplace similar, yank the powertrain and all the emissions hardware, install it in you project car, and part out and/or sell the engineless corpse for scrap. As a bonus, you could install speed parts that were designed for the car you got the engine out of and have E.O. numbers (headers, superchargers, etc.) on your project car, something that you can't do with an eRod (Doing that will brick the ECU, per CARB's demand.).

        Having said all that, the eRod program does (on paper at least) make registering a kit car or something like a repop '57 Chevy built without an actual '57 Chevy VIN much less of a hassle.

        • E-rods make sense within the scope of a big-dollar build on a 76-95 car, since you're already paying big bucks. No everyone has the space or patience to part out a second car and come out a couple grand ahead.

          I actually see them as most attractive for non-GM vehicles. RX-7, Supra, various BMWs, etc…

          Though, that does give me an idea…
          You could start a business doing the salvage equivalent of an e-rod. Yank the motor, ECU, wiring harness, emissions stuff, sell it along with the VIN and other paperwork needed for a BAR-approved swap along with instructions/consulting to make it happen.

  • buzzboy7

    The 6.5 TD "can" be a good motor. It needs a few things to be checked IIRC, harmonic damper, location of some electronic gizmo and maybe one other thing. Otherwise, they are about the best MPG option for "big" diesels.

    Grab a 6.5-TD from a mid-90s CK mated to an NV4500, and drop that baby in, backed with the 2.72 rears. NV4500 has good ratios for this as well with a granny first allowing some grunt with the 2.72 gears.

    If it were me however, instead of a GM Detroit, I'd be looking at a baby cummins, the B3.3 turbo with 85hp and 215ft•lbs, and mate it to an M5ODR2. Small package, plenty of power and good for the fuel sipping.

  • jeepjeff

    I had a similar idea a while back, but Ford, not GM. Lincoln Continental Mark IV with a 7.3 Powerstroke. I'd figure out a way to jam an M/T in there instead of having to shell out extra for an automatic controller. But I could definitely see this as a worthwhile project, albeit, not near the top of my pending list.

  • BlackIce_GTS

    I keep hearing stories about magical things happening with tuned Diesels. "I bored out my injectors with a power drill and yelled some hex code at my ECU, now I get 60mpg with 800 torque things!"
    So… I wanna do that. I was thinking more of a B-body though. Unfortunately, local emissions control has no age exemption.
    As a purely secondary concern, I am not what one would refer to as "a mechanic".

  • clunkerlove

    Two links that are relevant:
    a 6.5L '77 Vette
    an '85 Mercedes 380SL converted to diesel … (an alternate take on the American theme)
    I've looked high and low for the link to the story on the 30mpg El Camino diesel project from some years ago. A very promising article with long winded technical discussions on how to rebuild either the 6.2 or 6.5 for fuel efficiency, then install it into a 2nd gen El Camino. While a commuter Corvette is an intriguing idea, I'd rather have the fuel efficiency in a vehicle that can tow – but is still sporty. Despite this, I await the tidal wave of suggestions for a diesel Corvette.

  • While I would certainly drive the hell out of that 'vette with a 6.2 or 6.5 in it… I think a smaller (and much more reliable) Cummins 4BT might be the answer here.

    Check out . I wish I had something of my own to contribute to the site. While I haven't seen a 4BT corvette on there (yet), there's plenty of crazy swaps on there (Nissan 240sx with a 4BT!), and it appears the engine mounts up fairly easily to a 700R4 – which is to say it should theoretically match up to a 4L60E (basically the same transmission with a computer module added), or possibly a 4L80E with an adapter plate (which might actually be a tad unnecessary).

    There's a fairly lengthy thread on there about the guys that DD their swapped projects. Most of them get mileage in the 20's (most being the ones that are actually road legal and not purpose-built off-roaders), and are in vehicles significantly heavier than the 'vette would be.

    Just for reference, you can get a 4BT from a delivery van hooked up to a GM TH400 tranny. Newer ones have around 120 hp and 300 ft/lbs of torque. They can be modified for more, if desired. The 4L60E has a torque rating I believe around 335, so that tranny should work unless you build up the engine for more power (which I hear isn't the greatest idea for reliability).

    • The problem with the 4/6BT motors is that they're like 9 feet tall.

      You have to do a body lift (or crazy tall suspension lift) just to fit one under a Wrangler's hood.

      For some reason I have a hard time getting excited about a 4BT outside of somthing about the size of a CJ. The numbers just aren't there…and the 6BT is friggin enormous.


      Friend of mine did a 4BT out of a bread truck into a 2000 P71 Police Interceptor. Slightly quicker than it was with the 4.6 and gets 40mpg. Soon to come: Intercooler, injectors, and an HX35 off of a 6BT, with which he's hoping to get it in the 12's while returning more than 40 mpg.


    I'd do some suspension upgrading just for the weight reduction. The suspension components in the C3s are almost unbelieveably heavy. Some tubular control arms, some composite monoleafs (monoleaves?), and some lighter brakes will come in under $1500 if you know where to look, and will shave over 100 POUNDS (!!) of unsprung or semi-sprung weight, yielding massive gains in ride quality, braking and handling ability, and smaller gains in efficiency and power to weight reduction. You can get a bunch of weight out of the chassis with a few choice (and cheap) upgrades as well. For instance, the stock transmission crossmember comes in at almost 85 lbs, and can be relaced with a 15 lb tubular unit for a few hundred bucks if you buy one or less than $50 if you can fab it yourself. The stupod extend-o bumpers on the later cars can be replaced with the far lighter (and far better looking IMO) early body panels and bumpers for a large weight loss.


      Also, I'd choose a different diesel. The GM diesels sucked. Really really sucked. I had to help work on those in the Air Force, and they firmly established themselves as one of the worst engines I've ever dealt with. No power. Terrible torque production for being that large an engine, much less a diesel. Not very reliable. Insanely heavy. Like bhtooefr said above, I'd go with an VW AHT 1.9. With just some injectors, a downpipe, and an intake, it will make just as much power and torque as the GM engines (seriously, it will), it will weigh well less than a third as much, be more reliable, get WAY better economy, and all for barely more money. There are kits to put a number of transmissions like the T5 or the AX15 behind it as well.

      • chrystlubitshi

        I can attest to the VW AHT 1.9 TDi.

  • The Vette in the top image with the tyre under the hood:

    Is that a Radial engine?

    • Crash protection

      • JayP2112


    • Almost certainly, in my unbiased opinion.

      • NothingHappens

        Somehow I knew you would be plying these comments.

        • skitter

          Who else could buy a car off ebay small enough to qualify for free shipping?

          • NothingHappens

            [That was was a tire joke….(radial, bias, plys, etc…)….yeah, we're that awesome]

  • racer193

    My brother had trans planted a 6.2 in a 892500 chev that he blew the last 6.5 up in. that engine lasted about 25000 km in that truck when it was getting harder and harder to start he pulled it for another 6.5. When we tore the 6.2 down we found it was pretty much shattered with the heads holding it together. I guess the turbo four hundred and 4.11 gears and highway speeds where a little much. for it. That said my 86 burban lasted allmost 700 000km with its (never been apart) 6.2. Another thing to watch for is head gaskets at around 200 000km.

  • skitter

    Also, props to ebay for knowing their (drunken) market. I thought their sending four people to hang out at the Grassroots $2012 Challenge was on point, but Redusernab and wild projects is a whole other level.

    • Alcology

      They got bringatrailer to build a project corvette sourcing only ebay parts. they're just about done too

      • Not that we're jealous or anything…

        • Alcology

          I think they are paying their own money to do it?

          We could do it! …

          • Dunno who's paying for what…which rubs me ever so slightly the wrong way.

            I'm also not sure which would make me more jealous: having someone else pay to build my project car or having my website making enough money to pay to build my project car.

            • OA5599

              So are you supposed to actually build this thing, or is the ebay proposal just about driving clicks in "what if" scenarios? Is there a budget, or can you just buy a previously-flooded Bugatti and ditch the seized W-16 for a 'Busa?

              BTW, the first C3 Vette came out in 68, not 69, and any of the chrome bumper years tend to hold their value better than the disco years. Even more so if it's got an interesting and rare set of letters and numbers (L-88, ZR-1, ZL-1, etc.). If you're trying to do this on the cheap, search for a car that originally shipped with a catalytic converter, then got treated to a Corvette Summer's worth of Ekler's catalogue.

              • Answering the first paragraph is in the "We don't comment of products under development" category. I suppose I can point out that most typical Redusernab projects could be done well within a typical advertising/social media spend for a Real Company.

                The art of picking up a C3 is finding the goldilocks trashed example. Pre-smog, minimal Corvette-specific bullshit, completely undesirable options mix, shot motor.

                I went big here, but there's nothing saying you couldn't drive it with the stock TH350 in place, or other interim steps to get some utility out of the car while building it.

  • If you want to do C3 Corvette projects I might just donate my '77 Vette to the cause, provided it ends up in drivable condition and I get to keep it.

    I drove my '77 Corvette from 1990 to 1996 while in high school and college. I did about 4 round trips from Atlanta to Michigan with it. I would NOT recommend it as a commuter car if you have a long commute. If you do try to use it make sure you add extra heat shielding on the transmission. Your right leg rests on the transmission while you are driving. I had to keep a towel in the car for long summer drives.

    • chrystlubitshi

      I think all C3 drivers do the 'towel in the car' thing, t-tops or not… I think that is why they sell corvette-flag branded towels.

  • 'BusaVette. Just sayin'.

  • TrueBlue315

    "Numbers matching is for Sesame Street viewers." I'm about to shout this from the highest mountaintops to any 1964-71 American pony- and intermediate-body owners who will listen. I just wanted you to know that.

    • danleym

      No kidding. I get so sick of hearing that crap. Numbers matching is cool for a museum piece. If it's your thing, that's cool, too. But don't get all smug about it.

  • Van_Sarockin

    Great idea for a fun project. But that 'vette isn't especially aerodynamic or light. I'd be thinking about other cars to do a similar thing on. Like an Opel GT with a four cylinder turbodiesel. Or maybe a Lotus Eclat, to really bring down the weight and improve aerodynamics. But the most fun might be had from turning a big boat into a hypermiler. I once rode in a '72 impala with a V8 that had been carefully rebuilt, then mated to an automatic and differential that were optimized for highway cruising. The guy said he got over 30 mpg at 70 mph. And then you could go crazy, like putting a Cummins V8 into an old Jensen Interceptor. I think it would be perfect for that car's character.

    • How about a modern Duramax diesel v8 in a Buick Electra 225? You're onto something here. Take an old boat with a worn out big block and replace it with a modern efficient diesel. How about an Imperial with a Cummins turbodiesel? Sure, a Corvette with a 6.2 would make a nice commuter, with high mileage figures, but a big old Detroit Boat with a modern diesel with equally high mileage figures, with the ability to haul a 25 foot Airstream, seems much better to me. Without the Airstream, the Imperial or the Electra would get maybe 30 MPG, depending how the thing was set up. Also, black smoke at full throttle, FTW..

  • nate

    Dang the luck, I'm trying to sell an '81 project vette that stalled out in my garage.

  • AlLebo

    When I was in Germany back in the 70s there was a huge tax for engines larger than 4 liters. There I met a guy who owned a garage who had a 64 Tbird with the 428 removed and a Mercedes in line six diesel replacing it. Better mileage and higher speed on the autobahn due to tranny. Your idea has historical significance.

    • Van_Sarockin

      Nice inversion of the US motor in the Euro body story.

  • I visited many web sites but the audio feature for audio
    songs existing at this site is in fact superb.

красивые шторы в спальню


транспортно-экспедиционная компания