Inside The Belly Of The Beast

True gearheads, who work for magazines, live for one thing, getting the inside scoop on the "next big product" to hit our hobby. So when GM sent out the invite to come wrench together a new engine the answer wasn't just yes, it was "hell yes!" And, it turned out this wasn't just any old motor from the General, but the most high-tech engine every produced by GM, the 500hp LS7.

It so happens that GM is understandably proud of their newest mill and of the talented people that are going to make it happen at their new, state-of-the-art 100,000-square-foot Performance Build Center in Wixom, Michigan. The program included flying out various magazine guys for a day of automotive nirvana. We would work with the GM master builders to assemble an LS7 engine. From start to finish we would build it in exactly the same way it will be done in full production. Having worked on a few LS1 engines I was very interested to see what was new with the LS7 and also how it compared to the recently released LS2 engine.

With camera in hand and a notepad of paper, I arrived that the GM Performance Build Center in snowy Wixom. The day started off with a bonus, a discussion about the other motor that will be hand assembled at the new plant, the supercharged Northstar. An entire article could be devoted to the massive amounts of technology in this new caddy motor, but let's just say that it is an amazing piece of engineering. We were then given a PowerPoint show about the history of GM engines and the success they have enjoyed in everything from drag racing to NASCAR. Tom Stephens, GM group vice president, GM Powertrain, briefly touched on the enormous power being made by the V-6 and four-cylinder Ecotec motors. We learned from GM Performance Parts that the LS7 would be available as a crate motor sometime this summer, but a price was not yet available. At least for the foreseeable future, the crate LS7 will carry the titanium rods. Also, since the oil system is integral to the design of the engine, the LS7 crate motor will be a dry sump motor. In essence, the engine will be exactly like the one they will be shoehorning into the new Z06.

As detailed in our April 2005 LS7 story, it is important to note that the LS7 is a completely different animal than the LS2. This is not like the relationship between the LS1 and LS6. To get the required performance GM took a "systems-wide" approach in building the LS7. Many of the parts vary greatly from its LS2 cousin. The dry-sump system is a work of art and should actually make retrofitting one into some old musclecar easier due to its slim profile. While the titanium rods are expensive, they are necessary to allow the motor to reliably push 7000rpm on a regular basis. The heads are massive and are not only equipped with titanium intake valves, but have been heavily ported out as well. The LS7 is basically a race-quality motor for the street and it is assemble in a very meticulous fashion. Each LS7 is hand assembled by one of the master assemblers at the plant who takes personal ownership of the motor from start to finish and, in a nice touch, has their nametag on the finished product. Sure the crate motor will not be low buck but considering the technology employed in it the value is certainly there.

Oh, and when I say an LS7 is "hand assembled" don't get the idea that this resembles the way average people would put an engine together. Every operation is data-logged though the use of computers and bar codes. Bolts are torqued using electric, computer-controlled torque wrenches while some parts are installed using hydraulic pressure. At the end of the build, the actual torque spec of every bolt on the engine can be looked up in the computer. We were told that during actual production, if a critical part of the motor is dropped, like a main cap, then the entire block is sent to scrap (I would bet they guard the dumpsters so don't get any ideas). This combination of craftsmanship, technology and strict quality controls will allow GM to turn out a very consistent and very reliable engine. It takes an expert at the Wixom plant four hours to assemble a LS7 engine and plant capacity is about 30 engines per a week. We noticed that there is ample room in the plant to add another assembly run in order to increase production to 45 engines every week. With that, lets start putting one together.