Next Generation Racing

[hanaylor]

GM’s LS2 engine package is making its way to a stock car track near you

For gear heads, the Chevy Small Block is every bit the All-American icon as Mom and apple pie. Its small size, intelligent design and power potential have helped the Chevy Small Block make an appearance in just about every type of vehicle imaginable – including motorcycles and even airplanes.

One place where it has been most entrenched is in stock car racing. For decades the Chevy Small Block has been the most popular engine in stock car racing. And for good reason: the parts are widely available and largely affordable, they make inexpensive power, and they are easy for the average racer to keep running reliably. So as engine technology has developed and GM stopped producing carbureted first-generation small block engines long ago, the engine has remained the standard at race tracks across the country.



But that may be about to change. Midway through the 2006 racing season NASCAR legalized an innovative new race engine package for its Grand National Division Touring series. Few picked up on the option at the time, but beginning in 2007 and going forward it has caught on and is becoming much more popular among teams that aren’t afraid of trying something new.

Commonly referred to as NASCAR’s “Spec Motor,” this engine is based largely upon GM’s LS2 package, the fourth generation of the original small block. Unlike the LS2 found in Chevrolet Corvettes, Pontiac GTOs and other models, the Spec Motor ditches the fuel injection and computerized coil-on-cap ignition for a race standard Holley four-barrel carburetor and an MSD ignition (designed for a Ford, incidentally).

Engine Builder Carl Wegner

The Spec Motor was mainly developed by Carl Wegner of Wegner Automotive and Gary Nelson of Provident Auto Supply (but formerly of NASCAR). The idea through development was to create a race-capable engine using mostly off-the-shelf parts. And given its updated engineering, the LS2 made the perfect candidate. Capable of producing 520 lb./ft. of torque and 625 horsepower with a redline around 8,200 rpm, the Spec Motor uses a stock production LS2 block casting and stock cylinder heads. Wegner even kept the major dimensions for the stock block – including the main and rod journal sizes, valve sizes, cam tunnel location and size, and even the bore and stroke – to minimize machining costs. This allows the block to be pulled directly off of the GM assembly line and be almost ready for assembly, making it significantly cheaper than a properly prepared Bow Tie block.

In addition to the block, other stock components include the cylinder heads (although Wegner does do some mild CNC porting work), rocker arms (modified by COMP Cams®), and maybe most surprisingly, hydraulic roller lifters. Besides being relatively inexpensive, Wegner says the hydraulic lifters act as a natural rpm limiter. Still, because the valve train is relatively light with COMP Cams® Beehive™ Valve Springs, lightweight retainers and titanium valves, the engine can spin up to a racy 8,000-plus rpm. Race-specific components include a COMP Cams® camshaft and pushrods, JE forged aluminum pistons, Lunati crank and rods, an Edelbrock intake,
titanium valves and an 830-cfm Holley four-barrel.

“It’s definitely a race engine,” Wegner says of the package. “It’s not a crate motor that somebody is selling to racers that won’t hold up. It was designed for this purpose, and it isn’t sealed. So if something does break you don’t have to throw it out. You can tear it down and have it fixed.

“Just because it isn’t your standard small block” he added, “that doesn’t mean that your engine builder won’t be able to work on it. I’d say any second-year auto mechanic can put one together. We’ll build one for anybody who wants one, but we aren’t trying to cut out the other engine builders out there. Any racer can buy a parts kit and take it to any engine builder he likes. We’ve built money into the suggested price for the engine builder to assemble and dyno test the thing. So we are definitely not trying to cut the other engine builders out of business.”

Wegner decided not to make the Spec Motor a sealed engine because racers have found ways to cheat up sealed crate motors almost as long as they have been available. Instead, he came up with an ingenious marking system to tag every important part inside the engine. The tag is made up of a series of “dots” inside a square that a laser can read a lot like a bar code. Each tag contains an identification code that is as unique as a person’s fingerprint. The design of the dots within the tag is very specific and extremely difficult to counterfeit. The tags are made by a computer-controlled machine that makes the imprint using a diamond tip that precisely controls the size and shape of each dot. When scanned, the information contained on the tag can tell all sorts of information about the component, including its date of manufacture, who it was sold to and even if it was originally sold with the rest of the engine package or is a replacement part. Only tagged components are legal, and only Wegner produces the tags, so as a racer you can have confidence that your competitors are racing the same components you are. Incidentally, tags are also strategically placed in areas such as the intake ports to block areas that may potentially be altered to produce more power.

In addition, the Spec Motor has been designed to discourage any opportunities racers may have to cheat up the engine for extra power. Instead of a thick rulebook limiting what can and cannot be done to the engine, Wegner says he has basically overbuilt this motor with a few specific choke points to limit power. For example, instead of using an overly small carburetor to limit airflow into the engine, the 830-cfm Holley is actually larger than necessary. So the expense of having a carb specialist hand-build you a custom carburetor is eliminated. Also, he says the CNC work he does on the ports actually makes them on the larger size, so more port work isn’t going to help much. Instead, it is the intake and exhaust valves that are smaller than optimal. The reduced valve size holds the engine’s power in check and is also easily checked by pulling the heads and putting a set of dial calipers on the valves.

Engine Builder and Track Promoter Keith Simmons

After a successful debut in NASCAR’s Grand National Touring series, other tracks and racing series are picking up on the Spec Motor as a viable option for holding cost in check while still maintaining good racing. Racing promoter Keith Simmons has made the Spec Motor legal at his three Iowa racetracks—Dubuque Speedway, Farley Speedway and West Liberty Raceway—and says the results have been positive.

“The initial reception to the new engine from the fans has been good,” he says, “because the racing has been very good.

"I think these engines have a future in racing,” he adds. “As time goes on you are going to be able to find more of these engines in the junkyard so you won’t be forced to buy all new parts. Plus, they are a very easy way to produce 650 cheap horsepower. I went to COMP Cams® and we did a lot of valve train testing on this engine so that I could see what they were all about, and even with the hydraulic lifters they are good up to around 8,300 rpm. So they make a good, racy motor. I’m happy with it.”



Don’t Forget the Boats

Marine Engine Builder Keith Eickert

Race cars aren’t the only place where GM’s new LS2 power plant is making a name for itself. Engine builder Keith Eickert, owner of Kustom Engines in Palm Coast, FL, is also finding these motors are great candidates to power some very high-end speedboats.

“This engine lends itself to the marine industry nicely because it is a design with an aluminum block and heads,” Eickert explains. “Compared to the big blocks we are used to working with, its light weight makes it no comparison at all.”

“We are using this engine at 415 cubic inches,” Eickert adds. “Carl Wegner handles all the internals, and I just try to make the changes to make it a viable marine package. These engines really have as much torque as a production style big block, and when you consider you are also cutting 500 to 600 pounds out of the package by going with the aluminum small block, the LS2 really comes out on top.”

“Obviously, with what’s going on with the price of fuel these days, fuel consumption is going to be an issue. So if you can make the same power and weight half as much, you are going to be better off in terms of fuel consumption. It’s just an advantage
all the way around.”

Contact Wegner Automotive.