Here is a close-up look at the Crankcase. Notice the six-bolt mains with cross bolting.

 A few years back GM introduced the LS line of aluminum blocks and cylinder heads that are used to build EFI, small blocks, and now GM cars come of the assembly lines with the LS all-aluminum engine, but these blocks didn’t lend themselves to building and racing “big cubic inch” small blocks that make a lot of horsepower and torque. The new Racing Head Service LS block is the answer to those applications and problems.

The primary issues for engine builders with the aftermarket aluminum and steel LS blocks available to them is that while they are improved versions of the factory blocks they retain some limitations of the stock design. Those limitations hamper the LS engine builder who wants to build a really big cubic inch small block.

The RHS LS block has an external fixture for the “Knock Sensor” as well as in the stock location.

Aware of this dilemma, the research and development team at RHS went to work designing and testing several different versions of a GM LS engine block until they developed one that offers many benefits and options for performance engine builders and racing enthusiasts of the LS block.

Racing Head Service’s LS Race Block is designed with added clearances and performance features. It is available in both standard (9.240”) and tall (9.750”) deck heights with an extra-thick deck surface (.750”). This RHS block features a raised cam centerline and priority main oiling via an oil galley that is shifted to the outboard of the block to allow more rod clearance, allowing a much longer stroke (4.600”) while minimizing windage in the crankcase.

Using computer-aided design, the cylinder walls are Siamese cast with press-in spun cast iron liners. Cylinder liners are available in both standard deck (5.67”/5.87” – same as the LS7) and tall deck (5.94”/6.38”) lengths. Also featured is a 6-bolt head design with a full water jacket around each cylinder (based on the LS7 design). The crankcase is somewhat reminiscent of a Ford “Y” block or Mopar block with the crank recessed below the pan rail but with the added feature of cross-bolted mains similar to the Ford 427 blocks.