Chicago Auto Show engine porn: Mopar 8.4L V10
The Dodge Viper's V10 might sound like a garbage truck at idle, but who cares when it delivers 600 horsepower with emissions certification and a warranty? Still, for some, that's just not enough power, and so the Mopar guys have come through with some parts to take the new McLaren-engineered 8.4L up to 650 HP. We're going to take a closer look at some of these components after the jump, and feel free to click on any of the photos to get a high-resolution version from our gallery.
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Extracting more power from a 2-valve pushrod engine that already makes nearly 75 HP/L is no easy feat. So how did the Mopar boys pull off this daunting task?
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One of the most striking features of the stand-mounted engine is the set of massive tubular headers.
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The five individual equal-length primary tubes meet at a set of intermediate collectors, with air flow from the front three and rear two cylinders combining into larger-diameter secondaries before joining into the huge collectors. This is commonly refered to a a "tri-Y" design, and generally favors broad powerband instead of maximum peak horsepower.
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A pair of electronically-controlled throttle bodies, each with its own actuator, control airflow into the intake plenum. They look just about big enough to swallow a Cornish game hen. To achieve the hp increase over the stock engine, the incoming airflow is routed through a Mopar cold-air induction tract.
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The intake manifold is said to be a "prototype" version of the production item, with a highly-polished upper half, and black powdercoat applied to the lower. From the outside, we can't see any obvious differences compared to the production item, but we wouldn't be surprised if the internal surfaces were massaged somewhat.
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Black crinkle-finish valve covers and carbon-fiber fuel injector rail covers do nothing to improve power output, but they sure look menacing.
Also note that the massive oil pan ties into the bellhousing for maximum rigidity.
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Note that the indirect (port) injector is now located in the cylinder head (unlike the older versions of the Viper V10 that placed the injector in the intake manifold). The exact reasons for doing this are unknown, but the change was obviously aimed at improving charge distribution across the rev range.
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Reader Comments (Page 1 of 1)
Bob 2:12PM (2/08/2007)
Oh my...
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terry hodak 4:06PM (2/13/2007)
"The exact reasons for doing this are unknown, but the change was obviously aimed at improving charge distribution across the rev range."
Maybe they did it because the intake manifold runners meet the heads at an extreme angle(they should be going down, not sideways but remember this started life as a truck motor) and would jeopardize the atomization of the fuel into the air stream if they put the injectors upstream more, due to the drastic bends the fuel and air mixture have to go through on their way into the combustion chamber.
Just a thought.
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Spectral Flagellum 3:07PM (2/08/2007)
"The exact reasons for doing this are unknown, but the change was obviously aimed at improving charge distribution across the rev range."
Maybe they did it because the intake manifold runners meet the heads at an extreme angle(they should be going down, not sideways but remember this started life as a truck motor) and would jeopardize the atomization of the fuel into the air stream if they put the injectors upstream more, due to the drastic bends the fuel and air mixture have to go through on their way into the combustion chamber.
Just a thought.
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NoNameDenton 4:30PM (2/08/2007)
There is a Mopar engine I would not kick out of my engine bay
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Fabulo 5:01PM (2/08/2007)
How heavy is that engine? 650 hp at what RPM? Do you have torque numbers? Or better, a torque curve?
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FordMatt21 6:38PM (2/08/2007)
as much as i defended ford's new 6.4L when everyone on this blog seemed to attack it, i will say that this engine is the biggest waste i think i have ever seen. come on 650 hp? i hope this comes back and bites dodge in the ass.
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Dan 9:50PM (2/08/2007)
How come the bike engineers can make 110 hp out of a 600cc engine but the car engineers act proud when they get less than 100 hp/l?
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Ben 10:33PM (2/08/2007)
Isn't a "Tri-Y" header a 4>2>1 form for an inline four?
Also, more power in a Viper is rather poinless, isn't it? It's not like it can even put down the power it used to have.
Dan: brake specific power decreases as displacement increases.
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Ken 11:09PM (2/08/2007)
Dan: not positive, but I hear that a lot of bike engines need to be rebuilt after 10, 20, 30k miles and require a lot more care and maintenance.
Dodge could get 1000 HP out of it if they didn't need to meet strict regulations and the engine only needed to last 30,000 miles.
However, big engines are harder to get power out of.
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Jim 11:17PM (2/08/2007)
Dan said...How come the bike engineers can make 110 hp out of a 600cc engine but the car engineers act proud when they get less than 100 hp/l?
OK Dan, lets see those bike engineers get 100 ft lbs of torque per litre...and have 90% if that torque available from about 1,200 RPM up...
The large displacement makes the engine able to generate more torque at a lower RPM...
If you like small 100 HP per litre engines that have to be rev'ed to perform...and nothing wrong with that, but Honda makes your vehicle.
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titan 11:07AM (2/12/2007)
It's not about hp per litre when you have a big hood instead of a small area between your legs. If Dodge wanted they could have a four valve per cylinder. Or overhead cams. Or a turbo charger. Those would certainly result in a hp boost per litre.
But how many people are really complaining 650hp just doesn't cut it?
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titan 11:08AM (2/12/2007)
A day or two ago we saw a 350hp 6.4l diesel v8 for a pickup truck from Ford. Being diesel it provided reasonable fuel economy, all things considered. And it was only in the heavy duty pick up trucks, not the popular half tons.
Yet autoblog was full of people posting about stupid rednecks.
Where did those posters go today?
Here's a 650hp 8.4l v10 engine that is going in a two seater and I haven't seen any posts yet bashing people who will buy this.
Just seems a little inconsistent to me...
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Mr. Slice 9:19AM (2/09/2007)
Fabulo: The torque curve of the stock srt 10 engine in the 08 viper is reported to be as follows:
RPM HP TQ
2400 225 495
3700 410 550
4800 524 570
6000 613 535
The new redline is also reportedly as much as 250 rpm higher.
Ben: Among the upgrades reported in the 08 vipers are better tires (dodge has aparently decided to drop the runflats to save weight and improve grip) and a much improved differential.
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MikeW 10:14PM (2/11/2007)
The Viper had an e-gerotor, which is damn good. Maybe the programming was bad or the drivers were expecting a torque sensitive.
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Ali 11:20PM (12/22/2007)
So Sick
http://www.universitydodge.com
http://www.hollywoodchryslerjeep.com
http://www.emopardirect.com
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haynturtle1971 5:13PM (1/21/2008)
can it fit in a Dodge colt.
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