248.362.1188
TECH LINE [M–F / 9A–6P EST]

Engine Tech: Borowski Builds Mild-mannered 427ci With LS Next Block

LS-based engines have earned notoriety for power and performance while becoming one of the most popular choices for both drag racing and street-engine swaps. They have been strong, reliable engines in most applications, but then racers and engine builders soon began leaning on them with longer strokes, higher rpm demands, and stronger boost levels in addition to other traditional paths to power.

Unfortunately, these power quests sometimes revealed problems which ultimately prompted various upgrades and a few elegant solutions from the aftermarket. Such is the case with the Dart LS Next advanced cylinder block, a design refinement targeting some questionable design elements of the factory LS platform. The new block boasts hardcore racing features designed to upgrade oiling and crankcase breathing functions.

Engine builders are certainly selective about the parts dedicated to their signature crate engines; particularly since they serve as mobile billboards for the shop’s engine-building expertise. Borowski Racing Enterprises inRockdale,Illinois, is no exception. Building on a solid reputation established by founder Ted Borowski, new owner Ken McCaul decided to groom a new line of Chevrolet-based crate engines to serve the company’s expanding customer base. He took a hard look at existing OEM and commercial crate engine packages to identify the most desirable characteristics and components capable of serving a broad range of customer requirements.

 

 Recognizing the problem

“We didn’t necessarily want to dismiss the known power and cost effectiveness of traditional Chevy small blocks, but couldn’t ignore the tremendous popularity of GM’s LS engines and their growing resume of performance power parts,” says McCaul. “Being primarily a race shop with emphasis on drag racing, circle track and some marine applications; we considered all the important factors with particular emphasis on power potential and good longevity.”

(Left) The unskirted LS Next block adopts the proven Gen 1 small-block Chevy style crankcase configuration, but remains all LS up top. It’s currently available in cast iron and soon in aluminum. (Right) Note main oil gallery plug adjacent to cam tunnel and just below the two lifter galleries. Vertical oiling passage leads to the camshaft journals. Larger angled passage comes from the low volume priority feed main oil gallery ensure priority oil feed to the mains first and the camshaft second.

(Left) The block accepts a standard LS rotating assembly (left). Front and rear billet steel caps utilize four straight bolts. (Center) Note that crank placement is not identical to a small block, but slightly higher in the block to help accommodate correct fitment of LS front cover and oil pan components. Borowski used a Callies Compstar forged crankshaft fully compatible with any LS or LS Next block. (Right) Standard reluctor wheel makes this an easy bolt in and an ATI precision balance keeps things humming smoothly.

“We ultimately chose the LS design to capitalize on its current popularity and compatibility with current muscle cars and electronic fuel injection systems,” McCaul confirms. “But we wanted to take advantage of the new features offered by the LS-Next block from Dart Machinery.”

LS Next upgrades

Among the desirable attributes it offers are full priority main oiling with a stepped main oil gallery to ensure equal pressure and volume at the front of the block and a lifter gallery crossover passage with restrictor provisions. What makes the LS Next different is its traditional Gen 1 SBC-style lower end, eliminating the LS Y-block configuration and aligning the crank centerline with the oil pan rails. So it’s a hybrid construction. Gen 1 small-block style on the bottom and Gen III/IV LS small-block on the top; eliminating the possible high-rpm power fade and concern of separate main bays in the crankcase in the Y-Block design LS engine. This took more than a little engineering to figure out, but Dart’sRichard Maskinand knowledgeable contributors such as David Reher saw the opportunity.

Off-the-shelf Diamond flat-top pistons with standard valve reliefs were perfect for this application, yielding an 11.4:1 compression ratio with the standard L92 head combustion chambers. They swing on Callies Compstar H-beam rods fitted with ARP-2000 rod bolts.

“We’re very pleased with the results and the cost to value ratio of this package,” echoes McCaul.  “We like the top-end packages we can use on it and we’re very happy that the new Dart block provides the long term durability we’re seeking for our customers.”

These results were very much in line with their prior thinking and McCaul was pleased with the performance of the L92 cylinder heads for the naturally aspirated packages. At 640 horsepower the hydraulic-cammed pump gas engine is a sweet affordable player. And with the trouble free LS Next block easily supporting their program, they’re already eyeing an additional bump to 440ci, pricier heads and a 700-horsepower target for an N/A package at a somewhat higher price point.

 

 

SOURCES

Borowski Race Engines

Phone: (815)725-2727

http://www.enginelabs.com/engine-tech/engine/engine-tech-borowski-builds-mild-mannered-427ci-with-ls-next-block/

Menu