- OneDirt - http://www.onedirt.com -

Is Dirt Track Racing Finally Ready for the LS?

LS Lead Image [1]

One of the first LS motors in dirt racing is Chevrolet Performance’s CT525 crate motor, where it is mostly found in a few crate Dirt Late Model series. The setup keeps the stock LS’s individual coil packs and crank trigger but swaps out the fuel injection system for a traditional carb.

For old-school racers and engine builders, General Motors’ LS engine family is still considered a “new” engine. That is until you realize that Chevrolet first put out the LS1 in the Corvette all the way back in 1997. That means the engine has almost made it to its second decade of production.

And nearly two decades of production also means that we have nearly two decades of engine cores sitting in boneyards and garages nationwide. In fact, these days it is much easier to find an LS engine than it is an unmolested first-generation small block.

So if that’s the case, then why haven’t we seen more LS engines in dirt track racing? After all, racing is as much about innovation as it is driving, and we have always known dirt racers will flock to practically anything that offers better performance for less cost.

For years, the answer was pretty simple: Sanctioning bodies and track owners were afraid the engine would bring excessive costs as well as excessive cheating–in the form of traction control–and simply wrote them right out of the rulebook. The acronym “LS” is never mentioned, just some sneaky language that says the engine must have a carburetor, a distributor and a single coil. Besides the LS, that language manages to rule out almost all modern engine designs.

Currently the best performing LS heads are the LS7 design. RHS has improved on the performance of the stock LS7 head by raising the ports and CNC porting everything. [2]

Currently the best performing LS heads are the LS7 design. RHS has improved on the performance of the stock LS7 head by raising the ports and CNC porting everything.

But we’ve seen a change in thinking lately as Chevrolet’s crate motor program has gained traction in both asphalt and dirt racing. They began with the “602” and “604” crate engines which were based on the venerable first-generation small block. But with the success of those options Chevrolet Performance also quickly made available the CT525, a 525-horsepower carbureted crate engine based on the LS3. While the CT 525 ditched the fuel injection system for a carburetor and single-plane intake, it did keep the multiple coil packs and crank-trigger ignition. Meanwhile, NASCAR also unveiled its “Spec” motor, an LS complete with carburetor, distributor, mechanical fuel pump and even a single coil.

NASCAR’s spec motor isn’t found in dirt racing as far as we know, but there are several dirt late model sanctions that currently allow the CT 525. Still, what’s gotten our attention is a short track Modified racer that has taken the bull by the horns and is working with his sanctioning body not only to make the LS engine family legal but also bring in fuel injection. What’s interesting about this is the racer and engine builder, Dave Arce, isn’t a deep-pockets racer that’s trying to collect wins by out-spending the competition. Instead, he is actually showing how a mostly stock LQ9 (the truck version of the LS with an iron block) because of its improved ports can run pump gas and still be competitive with traditional high compression (and expensive) race engines running 110 octane.

“The LS architecture is significantly different from the first-generation small block,” says Kevin Feeney of Racing Head Service [3] (RHS). “And one thing that I think will really help the LS platform gain acceptance in dirt racing is the aftermarket stepping in with parts that help the LS feel more like a first-generation small block.

“For example,” he continues, “a few companies have intake manifolds for mounting up a single four-barrel carburetor, and some have come up with a front cover where you can run a mechanical fuel pump and a distributor off the front of the motor. In fact, we even have one specifically for Sprint Car racing where you can drive the dry sump oil pump, a magneto and the water pump off the front just like they are used to in more traditional Sprint Car motors.

All of the LS blocks use mostly the same architecture. RHS's LS race block is stronger than stock an utilizes windows in the bottom half of the block to alleviate the stock block's windage issues. [4]

All of the LS blocks use mostly the same architecture. RHS’s LS race block is stronger than stock an utilizes windows in the bottom half of the block to alleviate the stock block’s windage issues.

“Besides the Sprint Car front drive, we have several other products for the LS here at RHS,” Feeney continues. “And that includes our LS7 cylinder heads and our aluminum LS Race Block. I actually have two Sprint car teams out of central Ohio that have built engines using our LS products, and one is actually racing in the World of Outlaws right now.”

Feeney didn’t want to divulge the teams because he says they are trying to keep their efforts to themselves and he respects that, but he did say that their LS programs show promise. Even with RHS’s and other manufacturers’ support, they’ve had to fabricate a lot of components to get everything to work–particularly the Sprint Car’s iconic eight-stack mechanical fuel injection system–and the teams are still working their way up the learning curve. Still, it’s just another example of innovative engine builders and racers forcing the issue and embracing new ideas if they think it can help them find victory lane.

“The big advantage of the LS design is in the valvetrain,” Feeney says. “The heads flow better than any production 23 degree head from the gen one small block. But then with each update with the LS they just got better, too. They put those narrow cathedral ports in the intakes for the LS1, and then they improved airflow with the LS3 by going back to a rectangular intake port. When they came out with the LS7 they improved airflow even more by raising the ports. And when we developed the RHS LS7 heads we raised the ports more on top of that to get even more power out of them.

“Besides that, engine builders that have built both gen one and LS race engines will tell you that they can make good power with the LS, and the power is a little more usable because the valvetrain is so stable that they can push the rpms higher with the LS than they can a traditional small block.”

Feeney says one of the ways to help engine builders accept the LS engine is to make it work in the same manner they are used to. So for Sprint Car racing RHS produced a front assembly that allows engine builders to mount a traditional magneto, dry-sump oil pump and even the water pump off the front just like they do on a first gen small block. [5]

Feeney says one of the ways to help engine builders accept the LS engine is to make it work in the same manner they are used to. So for Sprint Car racing RHS produced a front assembly that allows engine builders to mount a traditional magneto, dry-sump oil pump and even the water pump off the front just like they do on a first gen small block.

The interesting thing about all this is Feeney has no dog on the fight. RHS has developed a broad range of performance small block cylinder heads along with its LS7 heads, so Feeney is more than happy to sell the customer whatever they want. But he also understands how easy it is to make power reliably with the more efficient LS platform.

“We are going to continue to evolve our LS cylinder head line as we find ways to benefit racers,” he says. “This year we introduced the Small Bore LS7 cylinder head because we had some people running UMP Modifieds and we thought we could help them out. In that class they have an iron engine block rule, and the six-liter blocks that are available from GM (the LQ engines) they are using have a small cylinder bore. Those blocks are relatively inexpensive, and so we reconfigured our LS7 head to fit their 3.900-inch cylinder bore. When you put the two together, the racers now they have a very potent package that’s surprisingly affordable.

“That project was a lot of fun, and I think things like that will catch on as racers and engine builders find what all they can do with the LS engine platform.”

 

Source

Racing Head Service (RHS)

(877) 776-4323

www.racingheadservice.com [3]