Chevy 350 CAMSHAFT MECHANICAL STREET SOLID ROLLER 260/266 LSA 109 0.588"/0.597" SMALL BLOCK CHEVY SBC

This camshaft is a solid roller mechanical-lifter design ground on Comp Cams Extreme Energy lobe family masters in the USA. The Extreme Energy series is the most widely respected aftermarket lobe profile for street-driven solid roller applications, designed to deliver aggressive valve acceleration while keeping seat velocity and closing-side ramps within limits that allow extended idle and low-rpm operation without premature spring fatigue or lifter wear.

At 260° intake and 266° exhaust duration @ .050" tappet lift, this cam sits squarely in the upper street / lower race window. The 6° duration split between intake and exhaust addresses typical Small Block Chevy exhaust port flow limitations — particularly on stock-port cathedral, Vortec, and similar production-style cylinder heads. Builders running heads with stronger exhaust-side flow (AFR, Trick Flow, Brodix, Dart, and similar high-flow aftermarket castings) may find the split sized appropriately or slightly conservative depending on the rest of the combination.

The 109° lobe separation angle (LSA) is tighter than typical for over-the-counter cams in this duration range. A tighter LSA increases overlap, which:

• Builds stronger cylinder pressure at lower rpm where it matters for street driving
• Produces a more aggressive idle character ("lope")
• Reduces idle vacuum compared to wider LSA grinds
• Improves mid-range torque on properly matched combinations

Lobe lift of 0.392" intake and 0.398" exhaust, multiplied through 1.5 or 1.6 ratio rocker arms, delivers valve lifts that match well to the airflow capability of most performance Small Block Chevy cylinder heads. 1.6 ratio rockers will pick up an additional 0.039" intake and 0.039" exhaust valve lift compared to 1.5 — useful where head airflow continues to climb past 0.600" valve lift.

Compression ratio: This cam works on pump-fuel street engines with 10.0:1 to 10.5:1 static compression on iron heads, or 10.5:1 to 11.0:1 on aluminium heads. Higher compression demands race fuel or methanol.

Cylinder head matching: This grind is happy on stock-port performance heads (AFR 195/210, Dart Pro 1 200/215, Trick Flow Super 23 195/215, Brodix Track 1, similar) through to mid-range race castings. On smaller stock-flow heads (Vortec, factory iron) the cam will overpower the head and lose efficiency at the top of its rpm range — a smaller grind would suit those builds better.

Intake manifold: Single-plane intakes (Edelbrock Victor Jr, Air Gap-style high-rise, Weiand X-Celerator) suit this cam's rpm range. Dual-plane intakes will compromise top-end power above 6,000 rpm.

Carburettor sizing: 750 cfm minimum for a 350, 850 cfm preferred for a 383 or 400.

Transmission and converter: For automatics, expect to need a 3,000+ stall converter. Manuals work fine across the rpm range.

Rear gear: 3.55 to 4.10 ratio suits street/strip duty. Highway cruisers will want overdrive if running 3.73 or steeper.

Solid roller cams use mechanical (lash-adjusting) lifters rather than hydraulic lifters. Valve lash must be set when the engine is built and rechecked periodically.

Typical lash settings for Comp Cams Extreme Energy solid roller profiles: 0.020" intake and 0.022" exhaust hot, though final lash should follow Comp's specification sheet supplied with the cam or your engine builder's recommendation.

Service intervals: Lash should be checked at first start, after the first heat cycle, after the first 100 miles of driving, and every 3,000 to 5,000 km / 2,000 to 3,000 miles of street use thereafter. Race engines should have lash checked between every event.

Break-in: Unlike flat-tappet cams, solid roller cams do not require a flat-tappet break-in cycle. However, fresh springs, lifters, and rocker geometry should still be cycled at moderate rpm for the first 20–30 minutes before sustained high-rpm operation.

Distributor gear: Any steel billet roller cam (including this one) requires a melonized steel or bronze distributor gear. A standard cast iron distributor gear will fail rapidly against a steel cam gear.

Emissions: This camshaft is intended for off-road, competition, and racing use. It is not legal for sale or use on emissions-controlled vehicles in jurisdictions that regulate aftermarket camshafts.