The Ultimate in Diesel: LB7 Duramax powered GN Clone

[Elmo187]

Back in the mid-'80s, Buick produced the Grand National, one of the quickest production cars of its time. Powered by a turbocharged 3.8L V-6, the car was capable of 14-second quarter-mile times stock and able to dip into the 13s with minor tweaking and a set of slicks. When we first noticed this black diesel hot rod on the Internet, we thought, "Oh, neat, a Duramax Grand National clone-he kept the turbo theme, but added a diesel." When we actually saw it and sat down and talked with owner David Morad, we realized this Buick just may be one of the most incredible diesel-powered vehicles we've ever seen. Don't believe us? Read on, and you'll see what we mean.

It all started about two years ago when David decided that although he loved his LB7 Duramax truck, he felt the diesel engine would be even more awesome in something a lot lighter. But what? He liked cars with newer interiors but didn't want to be hassled by the smog police, so the idea of a Grand National with a Duramax was born.

After his decision, David spent another year collecting anything he could that was Grand National-a hood, fenders, taillights, and bumpers were all acquired from parts traders, eBay, or wrecked GNs. Then he found the perfect car: an '82 Buick Regal diesel. The car had been converted to gas but was originally a diesel vehicle, so a Duramax would be a perfectly legal swap as far as the DMV was concerned. Then disaster struck. On the way home, the Regal's gas engine sprang a fuel leak, and the entire car burned to the ground.

Determined to stick with his plan even if he had to do it the hard way, David found an '81 Oldsmobile diesel and started again. The body modification list to turn the Olds into a Buick clone was immense. The car was cut in half, and the back clip was welded on from a Buick Regal to make it look like a Grand National. Then the parts were added: a hood, bumpers, a trunk lid, taillights, emblems, and David even went to such lengths as finding an original GNX dash plaque (a GNX was a special version of the Grand National) and aluminum bumper supports from an original GN. The deception is enough that he has actually been yelled at for doing that to an original Grand National. If that's not enough, the car's entire floorpan was cut out and raised up a couple of inches to make room for the big diesel's exhaust.

After a bit of calculating, David soon realized the stock chassis wasn't going to cut it, so an Art Morrison front-strut subframe was added along with a set of cross-drilled Wilwood disc brakes and a rack-and-pinion steering setup. For the rear, Art Morrison was used once again, this time supplying a four-link setup designed for a fully tubbed vehicle. Out back, a Ford 9-inch rearend with 35-spline axles, a nodular centersection, and a Detroit Locker provide all the strength and traction necessary to propel the Buick to warp speeds. Because of the diesel's low-rpm powerband, the rearend was fitted with a 3.23 axle ratio.

With the body and chassis sorted out, it was time to fit the engine and transmission. Just like with the previous steps, David took no shortcuts. The firewall (which originally had A/C) was smoothed and notched for exhaust clearance. Once custom mounts were built for the engine, inner fenders were formed out of aluminum to give the entire engine bay a smoothed look. David wanted to keep the stock hood line, so a custom oil pan had to be made for the engine, the oil pick up had to be modified, and the filter had to be relocated underneath the driver seat. David also didn't want a huge bulge in the interior of his ride, so a 4L85E transmission (the one that comes in Duramax-equipped vans) was used instead of an Allison, and it was installed on a custom transmission mount.

Courtesy of Diesel Power Magazine

[texlonghorn]

Wow, this has oddly always been a dream of mine actually, putting one of those diesels in a car. It is a dream come true!

[Attaus]

Wow.. that is f*cking impressive. If I could get the chance, I would shake that guys hand before anyone with a Ferrari or Lamborghini..

The dedication he has is something I only dream about. I was fooled too, and I consider myself to be a pretty avid enthusiast.

Aside from the perfect paint, almost identical exterior, and his respectful desire to not ruin an original GNX, that wheel/tire combo is dead sexy. Just look at that lip. Is that like 3 or 4 in the front and 6+ out back? I don't know.. it doesn't really matter. That's a badass car, and I don't even like diesels.

The only thing I'm curious about is the power numbers.

[AWDfreak]

DAM!!!

That man's hard work and extreme dedication is just...admirable.


Someday, I gotta do a project car like that! To literally build your own car must be an awe-inspiring experience.....

[millmAn]

Originally Posted by Attaus

The only thing I'm curious about is the power numbers.

I'm guessing the engine doesn't have much mods. It obviously has an air intake and the boost has more than likely been cranked up. Anyway, here are the specs for a stock Duramax:

The LB7 Duramax diesel is a direct-injected, turbocharged, intercooled, four-valve-per-cylinder V-8 that produces 300 hp and 560 lb-ft of torque. Starting from a blank sheet of paper, the 6.6L Duramax is recognized to date as the fastest diesel development program in the world.

http://www.dieselpowermag.com/tech/c...max/index.html

This car sure is badass and the work that has gone into it is amazing. But I would have gone an entirely different direction with the car -- I wouldn't have done the whole GN clone theme. I don't know what I would've done, but this car really doesn't turn my crank.

[Attaus]

Ah, so it basically takes the original idea of the car and expands it. 560lb-ft is nuts, and would explain how the stock motor can roast those 12-13" wide tires.

PS- Nice pun. =P

[Godzilla:PetroLHeaD]

The most Badass diesel car there probably is. I can't think of anything with a diesel engine in existence right now that is even 1/4 as cool as that thing. 560 lb.ft of torque makes my mouth water, literally. and that's what a stock Duramax makes. In a car as light as that one ( lighter than a truck at least), this guy definitely deserves one of Lsixer's cookies.

[VTEC_Dreams]

See, this is way cooler than the ZR-1.

That's what I was getting at in that thread. Ya jerks.

[Driftster]

WOOOOO

F***ING BAD ASS!!!

Nothing else will suffice in an explanation for this car.

Head to toe this car works..

The GN has always looked it's best black on black..Black paint with black wheels..
But this diesel makes it better, although i'm sure it sounds like ass running..

I'd love this vehicle.

[SRT expert]

Coolness oozes off of this thing. 100 times cooler than the ZR1. Sounds like this is an epically fun machine to create as well. Look at the meat on those rear tires as well... Very, very cool indeed.

[clutch]

A GN that could yank tree stumps out of the ground.


Simply an amazing smoker.

[Elmo187]

Originally Posted by Driftster

....although i'm sure it sounds like ass running..

actually, Duramax engines still have that V8 growl that other big diesel engines don't have.
http://www.youtube.com/watch?v=Nt-6uPdd0F4

[Driftster]

Actually..it sounds like ass running.

[clutch]

Arguing with Ty is like arguing with a brick wall, there is no give. Except unlike a real brick wall, Ty throws bricks at you.

[Nemphis]

I'm not a fan of diesel to the point that I hate the idea ...............



But I have some respect for this project although why would you take a classic American car with a V6 engine and put a big V8 derv in there instead ????????


Torque ??????