page_title: Chrysler Slant-6 engine
section_title: Hyper Pak
hierarchical_section_title: Chrysler Slant-6 engine / Configuration variants / High-performance variants / Hyper Pak
caption_attribution_description: This is a 4 bbl Slant-6 Hyper-Pak reproduction by Clifford Performance in a 1962 Plymouth Valiant.
context_page_description: The Slant-6 is the popular name for a Chrysler inline-6 internal combustion engine with the cylinder bank inclined at a 30-degree angle from vertical. Introduced in 1959, it was known within Chrysler as the G-engine. It was a clean-sheet design that began production in 1959 at 170 cubic inches and ended in 2000 at 225 cubic inches.
context_section_description: The Hyper Pak was a parts package made available from 1960 through 1962 at Chrysler Corporation dealer parts counters. The parts were made available to comply with the regulations of sanctioning bodies for racing events in which Valiants had been entered by factory-backed teams: All parts used had to be "stock" parts, the definition of which meant that they were available through normal factory parts channels. The Hyper Pak consisted of a very-long-ram intake manifold meant to accept an AFB 4-barrel Carter Carburetor, the AFB carburetor itself and an appropriate air cleaner, dual (front-3 and rear-3) cast-iron exhaust headers, a large-diameter exhaust Y-pipe to connect to these dual cast-iron headers, a larger muffler, a 276°-duration camshaft with appropriate valve springs and pushrods, a heavier-duty clutch, a manual choke control, a starter motor modification template and, in the full-race version of the package, high-compression pistons designed to increase the engine's compression ratio to 10.5 from the stock 8.5. The Hyper Pak was recommended for installation only on vehicles equipped with manual transmissions, for the camshaft was of such characteristics that a high idle speed was required to prevent engine stall-out. The Hyper Pak was primarily intended for competition driving, its road manners involving rough idling and poor cold-engine driveability, a high power band and poor fuel economy. In competition events it proved unbeatable. Eight factory-backed Valiants entered the 1960 NASCAR compact car race at Daytona Beach, and humbled the competition. The Valiants came in first through eighth. After a similar performance the following year, the race was dropped. A high-fidelity reproduction of the Hyper Pak intake manifold was created by Slant-6 builder Doug Dutra in the late 1990s. Subsequently the tooling was sold to a marketer of performance equipment (Clifford Research, 6=8) for inline six-cylinder engines.
caption: Reproduction Hyper-Pak intake on a Slant-6 engine
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