Many General Motors enthusiasts will already be well aware that the American automaker developed an experimental sixteen-cylinder engine in the early 2000s, which was eventually stuffed into the front of the Cadillac Sixteen concept. What many GM fans may not know, however, is that this over-the-top powerplant also found its way into a heavily modified GMT800-platform GMC Yukon.
Photo by Katech via The Drive
The story of the sixteen-cylinder GMC Yukon was covered last month by The Drive, who spoke to a former GM powertrain engineer familiar with the so-called ‘XV16’ engine program for its story. This Yukon based engine mule featured revised front suspension derived from GM’s heavy-duty pickup trucks, along with a modified frame that had been lengthened by a remarkable 16 inches, to accommodate the massive 13.6-liter (829 cubic inch) motor.
2003 GMC Yukon
The engineer said the GMC Yukon-based powertrain mule was once pulled out of its collection and dusted off so an unnamed GM executive could drive it around the automaker’s Milford Proving Ground, so they actually had the privilege to go for a ride in it. This person told The Drive the engine had a very smooth power delivery and an “interesting,” engine sound from within the cabin. They didn’t experience it at wide-open throttle, but with an estimated 1,000 horsepower and 980 pound-feet of torque on tap, this would have been one seriously fast full-size SUV. -especially for 2003.
As some readers may recall, GM commissioned the Michigan-based engine experts over at Katech to design and build its experimental sixteen-cylinder concept engine, which featured hand-ported LS6-derived heads, a billet steel camshaft and crankshaft, titanium rods and valves and forged internals. The motor was an incredible 45 inches long and weighed nearly 700 pounds, which explains why GM had to make such extensive modifications to the Yukon’s front end. This powertrain mule remains in existence today, a GM spokesperson told The Drive, residing in the automaker’s rather exclusive Heritage Center collection in Michigan. It’s unfortunately not open to the public, so it’s unlikely we’ll ever get the chance to see it, so let’s hope GM brings it out to an event or industry trade show one day in the future.
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Comments
13.6-liter V16 to a 1.4-liter 3-cylider turbo. How we have lost our way.
Not like theyre putting that in a truck, but whatever buddy. Also “lost our way…” nah how about a 1000hp electric Hummer that gets 47MPGe… seems like we found our way.
Peter:
Do you think a Yukon with a 1000 hp V 16 engine would sticker for LESS? 😂
“16 mpg actual” MPGe is a lie. Somehow our most modern truck gets the same economy as the vortec 8.1. At least that engine sounded good.
16 cylinder engines might be smooth as butter, but man, all that cylinder wall to volume! That’s going to be a huge radiator! Be better off with a big Bore like the 632zz.
pumping losses would also be an issue.
Just finding the 47mpge (which is a damn oxymoron stated by morons) after you have run out of those 47mpge.
Well we did not lose our way. Just no way to meet emissions and mpg regulations building cool stuff anymore.
If the government would back off we would see things like this.
But be aware anything with that engine at low volumes would be twice the Hummer price.
Explain Dodge with the Hell Cat engine in the Charger/Challenger/DURANGO/Cherokee , Ford with the 3.5 TTV6s in Expeditions and Raptors in 2022. Where as GM only slapping a supercharger at that in the Cadillacs, Camaros,Corvettes ONLY.
CAFE.
Thank Commifornia for that crap and I grew up there. My last California Camaro before I left the state could not outrun a fly.
Easy smaller engine with turbo chargers and superchargers generally get better emissions vs more cubic inches.
Also the Hemi is about to die and the Cadillac is going to live a short life.
We are getting a DOHC twin turbo flat crank V8 that will get better mpg, emissions and fit more vehicles.
The 16 was a cool idea but expensive and impractical.
Note the V10 at Chrysler lived only in a couple vehicles and was heavy and sounded like a bus engine.
but the V10 was used in a high volume HD truck, just like Ford. Volume over model range.
That is the couple vehicles i was referring to and both had short lives.
Large cubic inch engines are not as clean or efficient as a Supercharged or Turbo engine. Higher compression and boost will burn cleaner and create more power. That is why we have so many today.
Cause ford thing is a gimmick.
In reality the problem big engines have with emissions is due to cam lobe overlap. Look up lopey cams. Emissions get real bad when I burnt fuel passed from the intake to the exhaust without combustion. Direct injection fixes all that. Most idle NOS and I burnt fuel is consumed by delaying the spark on idle. Gen V small blocks are just as clean or cleaner than a small turbo engine. Hemis are still port injection, and are getting hit hard by CAFE. The reason they moved to the 3.0 Turbo is because fords gimmick is paying off. Chrysler also has a history of the “slant 6” IMHO, they would have been better served with a 4th gen hemi. If they added direct injection and multi air like from the tigershark motor they would have exceeded the fuel economy of the hurricane and made close to the same power of the hurricane HO in an NA engine.
Worse than CAFE, Hellcat sedans are subject to a $2100 gas guzzler tax. They took a $32k car and made it $78k. At that price, I much rather get a Corvette, which isn’t subject to gas guzzler.
One thing’s a fact. Ford is absolute trash. GM and Mopar have it figured out by sticking with higher displacements. You can’t tell me going electric and charging me more than 100k is the solution. I do not want to drive a cellphone on wheels where I get stuck somewhere with no charging station, and if I do charge I have to wait for a couple of hours for a full charge, nor do I want my cellphone car on wheel to have a depleted battery after 3 years. Absolutely outrageous.
Gm is following shortly behind as well as Stellantis. not sure if the batteries will last, but given the current trends it might very well be that the hunt for actual gasoline might be the new range anxiety over time. people will start rebuilding battery packs, just like motors and the battery warranty is battery is covered for 8 years or 100,000 miles. so in 3 years if your prediction is true, you would get a free battery replacement. really not a lot different than gas motors with DOD and AFM dying off when the 10thousand mile recommended oil changes do them in. I know it is tough to understand for certain age groups, but we have two types of electrical current in use, AC and DC. When connected to AC the charge time is at the mercy of the on board inverter/charger. the future will need end up being DC fast charging everywhere if the grid can be made to support it, and the business can get loans to install the infrastructure and charging systems. Then the charge time will be maybe 30 minutes or so. You should be asking why they cannot figure out a way to wirelessly charge these things or reduce weight so the tires don’t shred inside of 10,000 miles.
I remember this. I remember seeing the Cadillac Sixteen at the auto show in Detroit.
It’s a shame how at the time you could really feel how GM was turning a corner and Cadillac was going to reclaim their crown as the Standard of the World.
Instead, they built crap.
Union workers went on strike for (hilariously) better pay and benefits.
GM went bankrupt.
Even though I grew up in Michigan and belonged to a GM family (two people working there) I eventually had to concede, after buying two new GM vehicles, that buying a Honda or Toyota was probably a better move.
I saw the 16 at the Glenwood show in North Canton Ohio.
Pure show car with a lot of work to be practical.
My hope is the styling would have been used on a RWD sedan with a V8. But the bail out scrapped that and by the time they could do it the styling was old.
Show cars are a mixed bag. People get mad if you don’t make ‘em. Then if you do make ‘em and change them they get mad,
Finally if you build one and don’t change it they get mad because in real life they seldom make good cars with out changes. They are too low or the get stone chips in odd places, the roofs are either too low or high
The SSR you could not adjust the seats without opening the door. The 5th Gen Camaro people complained about the roof and visibility, they complained about the dash in real life that GM preserved from the show car. It looked cool but was not great in real life.
The 16 would need many changes and the cost would have been more than anyone would pay. We may see the similar cost issue on the coming halo car. Has Cadillac earned the image for a $300k car gas or electric? Hmm it better be a damn good car.
I do not understand the reliance on pushrod tech. When I saw the title, I expected an overhead cam , smaller displacement, like Mercedes, and many Euros do. I am a fan of over head cams, high rpms. But when I read these stories about large standard size pistons and pushrods, I just see another world war 2 allison engine, for aircraft and buses.
Go ahead , thumbs down. But 16 cyl is cool. But large displacement ?
When we were toung, it was always cubic inches = horsepower, but look at todays 2 litre 400 hp engines, and Raptor. Some serious good fun.
This was long ago and a cheap way to make a 16 cylinder was to merge two v8;engines.
This same company offers a v12 based on the Chevy wV8 and parts are cheap and easy to find.
Raptor is getting its lunch eaten by the TRX. I loved the GNX as a kid, even more the TTA, but in a truck the torque is the issue. the new turbo motors have numbers on paper, but in reality they seldom seem like they are there. but nobody is mentioning the 4 cylinder turbo Silverado’s how were they in reality? could they two a boat, did they really get that much better fuel economy? Do they have the same problems as the 1.4 turbo engines?
That is the couple vehicles and both had short lives.
Large cubic inch engines are not as clean or efficient as a Supercharged or Turbo engine. Higher compression and boost will burn cleaner and create more power. That is why we have so many today.
If done correctly like my 2.0 I ran 23 PSI of boost on pump gas with the full GM warranty as it was their tune. Right at 300 HP from 2.0 liters.
On the contrary most turbo engines today are very large torque monsters and spread the torque over a flat curve.
The GNX and Turbo TA were not very good Turbo engines compared to today.
With Direct Injection and oil cooled pistons they can run higher compression and much higher boost to get not only a clean and more efficient but more boost for more torque and HP.
Toss in variable timing and you can control the torque over a wide range.
My 2.0 was limited to 315 FT LBS due to the transaxles in ability to hold more power. The Solstice with RWD was limited to 340 FT LBS. The same engine with a better tranny could go much higher.
The dirty or clean secret is this. The search for more cleaner engines has resulted in turbo and Supercharged engines that are seeing boost and compressions we never saw before this leads to more efficient engines but also the by product more HP and Torque.
This is why they investigated the compression ignition engines running gas and 19-1 compression where no spark was needed much like a diesel. But even it is not enough to meet coming numbers hence the investments in BEV.
Spoken like a European. Fact is the US doesn’t tax based on obsolete notions of displacement, like Europe did. A large displacement, slow revving engine offers more low-end torque and a wider torque band. It is more efficient due to lower viscous drag from oil and air.
In fact, European manufacturers have done just this for US-market engines to meet CAFE. See the BMW eta models.
Because you’re slow revving, pushrod works just fine, and saves you a lot of volume, mass and manufacturing cost. (Just look at a picture of a LS next to any OHC engine)
High-revving euro engines exploit the fact that HP and torque are advertised by one number, and the Europeans don’t use SAE J2723 HP standard which requires a certain width. So, you get your “400” hp for a tiny fraction of a second during acceleration, and that’s it.
Also, European powertrains don’t last in the US, it’s well known. The US driver 1 mile for every 1 km a European driver does, and so they are well-known to be under-engineered and failure prone.
We haven’t lost our way, we lost our minds sniffing bath salts. 20 years ago you could buy a Camaro with a 350 325hp that got 28mpg on the highway. Today the 4 banger 275hp Camaro gets 29mpg on the highway.