1987 Mazda B2600 2.6L mileage: 150,000. I just completely overhauled the engine had it bored out to ten thousandths of and inch, put a remanufactured head on it, new pistons, cut the crank with new rods and mains. When I reassembled everything, I was extremely careful to torque every bolt to the specs that I have in my repair manual. After I got everything together and ran the engine, I found that the engine was overheating with or without the thermostat installed. I have good flow through the radiator and no leakage past the rings or through the head gasket. It is not leaking antifreeze anywhere. Please help.
Here are some things to check. Is the ignition timing adjusted properly? Is there exhaust gases in the cooling system? That can be easily checked by a radiator repair center with a sample of coolant with engine running. Is the fan clutch engaging when the engine is hot?