The newly invented pulsed compression reactor functions similarly to an internal combustion (IC) engine, but unlike the IC, it does not suffer the IC's limitations. While peak temperatures are in the order of 1500-5000 K, and peak pressures in the order of 100-2000 bar, the average temperature and pressure of the reaction zones are much lower. The piston can reciprocate at over 200 Hz. The total time the reaction zone is at peak pressure and temperature every cycle is a mere fraction of a millisecond. The experiments presented in this article were designed to determine the penetration of heat into the reactor cover. Seven thermocouples were inserted into the top cover of the pulsed compression reactor, monitoring the progress of heat through the reactor cover during operation. This is used to calculate the effective heat transfer between the reaction zone and cylinder. The experiments were carried out under operating conditions lower than those that might be used in industrial applications. The goal was to investigate the strength of the proposed experimental method. The conclusion is that the experimental method is very insightful, and gives interesting results with respect to heat transfer, and can thus be applied for industrial operating regimes. The energy loss due to heat flowing from the reaction zone to the cover in these experiments was about 1.6% of the energy spent for the compression of the gasses, when the reactor is still at ambient conditions. (C) 2009 Elsevier Ltd. All rights reserved.