The blocks themselves are made in England by the same folks that used to do the Cosworth blocks for IRL racing. Scooter Brothers said he would have preferred to have the block cast in the U.S. but he could not find a foundry that wanted to cast the block to the specifications he demanded. In fact, the U.S. foundries recommended that he take the job to the English manufacturer.
In order to see if the LS blocks they had engineered were as good as they thought they were, Comp Cams’ Brian Reese built and dyno tested a motor using the block. They built a 500-inch small block.

“We didn’t have to grind or clearance any part of the block to build a 500-inch engine,” Reese said. “Because of the raised camshaft and more room we had in the crankcase we didn’t have to grind a thing to have plenty of clearance.

“The engine was built using a set of dished pistons and a some nothing special heads. We used a single four-barrel intake and carb and burned racing gasoline,” Reese explained.

On the dyno, the engine made 700 hp and over 500 ft-lbs of torque at under 5000 rpm.

SEE NEXT PAGE FOR DYNO RESULTS

For quality control assurance, RHS performs a CT scan on each block (similar to a medical CAT scan) to maintain maximum casting precision and consistency. Combine all of these features with a superior finish quality, thanks to the RHS patented Clean Cast Technology™, ultra-precise computer aided design and extra surface material to allow custom machining, and you’ve got a GM block that sets a new benchmark for LS horsepower, torque and durability.

Currently RHS has taken delivery on and shipped about 30 of these blocks to various customers ranging from street to full race applications

Here is the short block used to build the 700hp dyno test engine. Notice siamesed sleeves.