We have previously proposed a new type of rocket engine with a compressive combustion principle based on the collision of supermulti-jets with pulse, while some combustion experiments qualitatively indicated a possibility of nearly-complete air-insulation and noiseless high compression. In this report, the pressure near the collision point due to the supermulti-jets colliding around the chamber center is quantified by experiment and three-dimensional unsteady computation. Then, combustion experiment done at a very lean burning condition with upstream fuel tank condition of about 3 bar and for only a very small combustion-chamber diameter of 18 mm reliably and repeatedly measured thrust over 100 N. This level of thrust was also obtained by calculation from measured chamber wall pressure using quantified pressure increase near the collision point. Thrust level of small conventional rocket engines is under 50 N under the same conditions. This shows the high potential of our new rocket engine. A conversion analysis also showed that the present new engine due to the supermulti-jets colliding with pulse has a possibility of specific impulse comparable to that of a large conventional rocket engine. Combustion computations are also being done, which may show combustion efficiency of about 90%.