Abstract: The effects of different engine bench test schemes and test conditions on thermal balance performance test resultsare studied experimentally on a GDI engine with integrated exhaust manifold. The test results show that compared with the traditional engine heat balance bench test method, the heat balance test scheme based on the real vehicle radiator, cooling system tubes, intake and exhaust pipes and accessories, can reduce the adverse impact on the heat balance test caused by pipes change, such as system flow resistance increase, heat transfer losses increase , uncontrollable coolant flow, too small temperature difference between the inlet and outlet of the engine, etc., and the test results are closer to the real vehicle state. The inlet air temperatures after intercooling, coolant temperatures and on-offcooling fan have a significant impact on the results of heat balance test. The exhaust manifold of the engine with integrated exhaust manifold is built into the cylinder head, which results in a significant increase in heat dissipation of the engine cooling water jacket. As a result, the cooling system must also provide greater cooling capacity to meet the needs of the engine heat balance

Key words: gasoline direct injection engine, integrated exhaust manifold, heat balance test, heat flow distribution