Timing Specs for a Chevy Small-Block
by Rob Wagner
Chevrolet's small-block V-8 engine timing specifications depend on the cubic-inch displacement and whether a manual or automatic transmission matches the engine. Small-blocks have cubic-inch displacements of 283, 307, 327 and 350.
The 283
The 283-cubic-inch V-8 has the plug gap set at -.35. The point gap is .019. The dwell angle is 31-34. The ignition timing is 4 degrees Before Top Dead Center (BTDC). The engine idle is 500 rpm for standard transmission and 475 rpm for automatics.
Hot Idle Differences
The 307 V-8 features spark plugs with a -.35 gap and .019 points gap. The ignition timing is 2 degrees BTDC. The hot idle is 700 rpm with a manual and 600 with an automatic.
BTDC Changes
The 327 V-8 specifications are nearly identical to the 283, except for the ignition timing. Model year 1965 250-horsepower 327s have an ignition timing of 4 degrees BTDC, while the 300-horsepower version has an 8-degree BDTC. The 1966 versions have an ignition time of 2 degrees After Top Center (ATC). With the manual transmission, the 327 idles at 475 rpm (with an automatic it idles at 450 rpm).
350's Similar Specs
The 350's timing specifications are almost identical to the other small blocks. However, the ignition timing for the 255-horsepower version with manual transmission is at Top Dead Center and 4 degrees BTDC with automatics.
References
Writer Bio
Rob Wagner is a journalist with over 35 years experience reporting and editing for newspapers and magazines. His experience ranges from legal affairs reporting to covering the Middle East. He served stints as a newspaper and magazine editor in Saudi Arabia and the United Arab Emirates. Wagner attended California State University, Los Angeles, and has a degree in journalism.
