Experiments were conducted on an uncooled 20,000lb-thrust gaseous-H and LOX rocket engine over a range of chamber pressure from 45 to 300 psia and oxidant-fuel ratio from 2 to 7. Combustion dead times were measured and compared with dead times calculated from frequency data for two assumed combustion models. Measured combustion dead time decreased with increasing chamber pressure at constant oxidant-fuel ratio or LOX injection velocity. This dead time also decreased with oxidant-fuel ratio at constant chamber pressure or O injection velocity. For the engine model where combustion dead time was considered to be the inverse of twice the measured chamberpressure frequency, only a fair agreement with the measured dead time was obtained. When the measured chamber-pressure frequencies were corrected for gas-dynamics effects in terms of the gas residence time, close agreement with the measured dead times was obtained. (Author).