Aluminum engines bring a lot to any motorsports party from drag racing to road racing to autocross.  They cut about 100 lbs from the nose of the car.  This greatly improves steering and braking thanks to not only the weight reduction but the better balance from front to rear.  Straight line only?  Going fast is weight to horsepower - not just horsepower.  Aluminum also transfers heat better than iron, so these blocks are easy to keep cool.

These RHS LS bare race blocks are designed to meet the needs of today's high performance engine builders and racing enthusiasts. These blocks are available in standard and tall deck height combinations and are engineered for maximum clearance around a 4.600 in. stroke crankshaft. With their unique design, RHS engineers were able to minimize windage in the rotating assembly, leading to superior engine lubrication at higher rpm. To make them friendly for existing race applications, these blocks contain both factory and motor plate race mounts for Gen I, II, III, and IV engines.

RHS LS bare race blocks each receive a CT scan to ensure maximum performance and consistency.  This is a really big deal as it is the only way to make sure there are no voids in the block.

Standard features include:

• Designed from aircraft-quality A357-T6 aluminum
• Siamese cast bore walls (4.125 in. or 4.165 in. diameter) with press-in cast iron sleeves
• Machined with 55mm cam bearing journal
• Available in standard (9.240 in.) and tall (9.750 in.) deck heights with beefy deck thicknesses (.500 in. standard/.750 in. tall deck); standard (5.87 in.) and tall (6.38 in.) deck cylinder sleeves are available
• 6 head bolt design with full water jacket around the cylinders' walls; large windows in the valley allow access to an inboard 6th head bolt
• Block design includes large front and rear AN-12 side feeds for serious dry sump setups
• Material for oversized lifters with lifter bosses that are designed to clear tie bar style lifters