450-degree temperature differential
Of course, nothing is really free-especially when it comes to building high-performance engines-and Katech squeezes some of the value from its short-block by using a production GM 6L cylinder block and resleeving it in-house with 4.125-inch bore liners.
The sleeves are Katech's design and made of centrifugally cast ductile iron. To install them in the block, liquid nitrogen is used to help create a 450-degree temperature differential between the block and sleeves. This allows the iron sleeves to slide into the aluminum block without the pounding that occurs with a typical press-type fitment.
When the sleeves are seated within the block, the block and sleeves are carefully brought to temperature equilibrium. A special fixture is used to apply torque on the liners to prevent them from lifting during the process.
Additional details of the sleeves and resleeving process include:
.The sleeves are machined and inspected, then grouped in sizes within 0.0003 inch.
.Connecting rod clearance is machined into the bottom of the sleeves to ensure adequate clearance for the 4.000-inch stroke.
.4.125-inch bore sleeves for a 427-inch engine have a 0.075-inch wall thickness all around.
.The finished block is double-vacuum impregnated to ensure against leaking.
"With our tight quality control process, we think the resleeved 6L block makes a great product," Katech's Caleb Newman says. "We have seen great success with it in very powerful engines."
Assembly processes of the Value Short-Block are as regimented as the block preparation. The reciprocating assembly is balanced and blueprinted, including the use of highly accurate air-based measuring devices from Air Gage Company, which are used to blueprint the crankshaft journals, main bores, etc. Katech uses these tools when building Corvette racing engines, lending a nice rub-off effect for a higher degree of precision on its customer-based street engines.
Also, each short-block-actually, every engine Katech touches-is serialized and logged into a database. That means years down the road, the assembly details and specifications can be retrieved, even if the engine changes hands.
As for the reciprocating assembly parts themselves, they're all expectedly high-strength, all-forged materials from names like Cola and Callies. The Value Short-Block assembly only includes the crank, rods, and pistons, but the blueprinting steps make it a painstaking build process.
"Based on customer preferences, we found that the basic reciprocating assembly is what people really wanted," Newman says. "Things like the camshaft, heads, and more are the items that are individualized. We're happy to help in those areas, too, but the Value Short-Block is the foundation everybody can build on."
The accompanying photos provide an overview of the short-block blueprinting and assembly process. There's also a sidebar story on what an engine built from a Value Short-Block delivers on the dyno.
Every strong engine needs a sturdy foundation, and it appears Katech delivers it at a reasonable price. It's fun living in the new golden age!
To achieve 427 ci, the 6L block's cylinder sleeves are removed and replaced with 4.125-inch sleeves. They're made of cast ductile iron, and deliver a sturdy 0.075-inch wall thickness all around. The sleeves are installed using a temperature differential that allows them to slide into the bores; they're set when the aluminum block and iron sleeves are brought to temperature equilibrium. | 
All of Katech's short-blocks, engine assemblies, and other components receive identification numbers that allow the parts to be tracked years after they leave the shop. The specs are logged into a database and are available for reference should the engine/cylinder block change hands or vehicles. | 
The Value Short-Block is completely balanced and blueprinted, which means that before the assembly starts, the crankshaft is balanced and the journal dimensions are inspected. |