1966–1969 Pontiac Tempest/LeMans Sprint OHC-6 Guide

1966–1969 Pontiac Tempest/LeMans Sprint OHC-6 (A-Body)

Historical Context and Development Background

Pontiac’s 1966 introduction of the belt-driven Overhead Cam Six (OHC-6) stood apart in a domestic market content with pushrod inline-sixes as economy fare. Spearheaded within Pontiac’s engineering ranks as a lighter, freer-revving alternative to the division’s V8s, the OHC-6 arrived in the intermediate A-body Tempest and LeMans as an answer to buyers who wanted European-style responsiveness without stepping up to a big-cube GTO. The architecture married a specially developed Pontiac single-overhead-cam cylinder head and cam carrier to the proven Chevrolet 230/250 inline-six block. The signature toothed rubber timing belt—uncommon in American cars at the time—reduced noise and complexity versus a chain or gear drive and allowed the valvetrain to live at sustained higher rpm.

From 1966, buyers could specify a base 1-barrel OHC-6 or the Sprint package, the latter calibrated for real performance with a higher-compression head, a more aggressive cam profile, dual exhaust, and a Rochester Quadrajet four-barrel. In 1968 displacement increased to 250 cu in, improving mid-range torque. Within Pontiac, the OHC-6 program complemented the division’s burgeoning performance image by offering a distinctively engineered six, while in the broader market it undercut Ford, Chevrolet, and AMC rivals whose inline-sixes remained cam-in-block. The Sprint LeMans/Tempest thus carved a niche—lighter on its nose than a V8, more willing to rev than any domestic six of the day, and imbued with the chassis tuning Pontiac bestowed on its intermediates.

Engine and Technical Specs

The OHC-6 used a cast-iron block with five main bearings and a Pontiac-designed aluminum cam carrier and valve cover. A fiberglass-reinforced toothed belt drove the single overhead camshaft. The base versions employed a Rochester Monojet 1-barrel carburetor and moderate compression; Sprint specification added a Quadrajet 4-barrel, higher compression, a hotter cam, specific ignition and exhaust tuning, and a 6,500-rpm redline. Displacement grew from 230 cu in (3.8 L) to 250 cu in (4.1 L) for 1968–1969.

Driving Experience and Handling Dynamics

The Sprint OHC-6 transforms the A-body’s demeanor. The lighter front end compared with a Pontiac V8 sharpens turn-in and reduces understeer, and the engine’s willingness to rev beyond 6,000 rpm gives it a distinctly European cadence. Period cars with the 4-speed and performance axle ratios (3.55:1 and 3.90:1 were commonly specified) respond crisply off the line, the Quadrajet’s progressive secondaries opening with a satisfying surge in the midrange. The valvetrain’s smoothness is a defining characteristic; with the cam up top and a belt drive, the engine is quieter and less thrashy than contemporary pushrod sixes when worked hard.

Chassis hardware mirrors other Pontiac intermediates: unequal-length control arms with coil springs up front, a triangulated four-link live axle with coils out back, and recirculating-ball steering. Spring and shock calibrations varied by option content; Sway bars, quick-ratio power steering, and higher-rate springs could be bundled with certain handling or Sprint-related packages. Brakes were finned drums as standard; front discs became optional during the run, a worthwhile upgrade for sustained mountain driving or track-day curiosity. The result is a car that feels eager and balanced on a winding road—more delicate than a GTO, with less outright thrust but better poise and a more nuanced throttle-to-chassis conversation.

Performance Specifications (Representative Period Test)

The figures below reflect a representative period road test of a Tempest/LeMans Sprint with the 230-cu-in 4-barrel and 4-speed manual. Exact results varied with rear axle ratio, body style, options, and test methodology.

Variant Breakdown (Tempest/LeMans OHC-6)

Pontiac offered the OHC-6 across Tempest and LeMans lines in multiple body styles. The Sprint package denoted the high-output OHC-6 with the 4-barrel carburetor and associated performance equipment.

Ownership Notes: Maintenance, Parts, and Restoration

• Timing belt: The OHC-6 uses a toothed rubber belt with a tensioner. Period service literature advises periodic inspection and replacement as a wear item; age and storage can be as relevant as mileage. Tensioner bearings and seals are common refresh items during restoration.
• Valvetrain: The Sprint’s high-rpm calibration is robust when fed clean oil. The cam runs in the carrier’s journals; consistent oil pressure and quality matter. Unlike many period sixes, there is no routine manual valve lash adjustment on these engines.
• Fuel and ignition: Rochester Monojet (base) and Quadrajet (Sprint) parts and rebuild kits are widely supported. Correct distributor advance curves are important to realize factory performance, especially on Sprint calibrations with higher compression.
• Cooling and belts: Access to the front drive is straightforward; water pump, accessory belts, and hoses should be replaced if age is unknown. Verify cam belt cover integrity and correct belt tracking.
• Transmissions: Manuals (3- and 4-speed) deliver the most from the Sprint. The 2-speed ST-300 automatic was common; a 3-speed automatic became available later in the run. Overhauls and parts for these GM units are routine.
• Brakes and suspension: Drum systems benefit from meticulous adjustment and quality linings. Factory-style front discs (where fitted/retrofitted using correct-era components) materially improve confidence. Bushings, ball joints, and shocks are shared with other A-bodies and readily sourced.
• Restoration difficulty: Driveline parts availability is generally good; Sprint-specific pieces (air cleaner assembly, exhaust manifolds, some brackets, and badging) take patience to find. Pontiac Historical Services (PHS) documentation is the gold standard to verify factory Sprint specification on a given VIN.

Cultural Relevance and Market Perspective

Contemporary advertising leaned into the technical novelty: “America’s only overhead-cam six.” The Sprint cars gave Pontiac a legitimate small-bore performance angle, with a willingness to rev that resonated with enthusiasts who were as interested in balance and feedback as they were in brute torque. While overshadowed in-period by the GTO, Sprint OHC-6 Tempest/LeMans models have since earned a loyal following for their engineering and character. Publicly documented sales have shown that correct, well-restored Sprint cars trade at a premium over base sixes and below comparable V8 LeMans and GTOs; rarity, options (4-speed, disc brakes, axle ratio), body style, and documentation are the key value drivers.

FAQs

How much power did the Sprint OHC-6 make?
Factory gross ratings reached 207–215 hp for the 230-cu-in Sprint (1966–1967) and up to 230 hp for the 250-cu-in Sprint (1968–1969). Base single-barrel versions were typically rated at 165 hp (230) and about 175 hp (250).

What is the redline on Sprint models?
Sprint-calibrated engines carried a 6,500-rpm redline, a defining trait of the package and a rarity among American sixes of the era.

How can I verify a real Sprint car?
Confirm equipment (Quadrajet 4-bbl, appropriate Sprint badging, dual exhaust, higher-ratio axle options, and correct engine components) and, most importantly, obtain Pontiac Historical Services (PHS) documentation for the VIN and build manifest to verify the factory Sprint option.

Are OHC-6 parts hard to find?
Core engine service parts are available. Sprint-specific items (air cleaner, intake, exhaust manifolds, some brackets) are less common but can be sourced through marque specialists and the enthusiast community. Carburetor parts (Monojet and Quadrajet) and ignition components are widely supported.

Known issues to watch?
Age-hardened timing belts and noisy tensioner bearings, vacuum leaks around aged hoses (especially on Quadrajet Sprint setups), and neglected cooling systems are typical project-car concerns. As with any 1960s engine, correct ignition timing and carburetor calibration are essential for drivability.

How does it drive versus a V8 LeMans?
With less weight over the nose, an OHC-6 Sprint feels more eager to change direction and prefers being worked through the gears. It lacks the effortless low-rpm thrust of a V8 but rewards with a sweeter, higher-revving character and better balance.

What transmissions were offered with the Sprint?
3-speed and 4-speed manuals were available and pair best with the Sprint’s powerband. The 2-speed ST-300 automatic was also offered; a 3-speed automatic became available later in the run.