Setting up ignition timing for modified engines – Compression Ratios

Standard MGB is in the range of 170 – 180psi (hot engine, open throttle). Modified engines may be quite a bit more than this, depending on compression ratio and camshaft type, and may even have less cranking compression than standard. (High compression ratio raises it, “hotter” camshafts reduce it due to the later closing of the inlet valve) If your compression is less than 150psi, it will start to affect low end performance quite significantly.

Read the full article at …… http://mgparts.co.nz/setting-up-ignition-timing-for-modified-engines/#