Circle Track Crate Engine Technical Manual - Chevrolet Performance

Engine Components
A lot of engineering & extensive testing goes into each component in the GM circle track engines.
The parts are tested to production standards and pass hundreds of thousands of miles before being
released. Quality control standards are maintained during assembly of each engine. This section
covers some of the differences between the major components in the three engines.
Engine Blocks
All three engines are assembled with brand new 4 bolt main blocks with cast iron caps. The main
caps are straight bolts. They are machined to factory specifications. The blocks are designed to use
1 pc rear seal crankshafts. Photo to the right shows the 1 pc rear seal adapter which reduces oil
leaks. It does require a special flywheel that is balanced correctly for these applications.
Pistons
p/n 14088556 rear seal retainer
The piston on the far left (below) is installed in 19258602 engines. This piston has a grafal coating
on the skirt. The piston in the center (below) does not have a skirt coating and is installed in
88958602 engines. They both are a cast aluminum dished piston with 4 valve reliefs.
The piston on the right (below) is installed in 603 & 604 engines. It’s a flat top piston with 4 valve
reliefs made from high-silicon aluminum.
Piston in 19258602 Piston in 88958602 Piston in 88958603/604
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