Before installing the turbo kit, I had the viscous propeller removed and decided to install a 16-inch electric fan instead. A second temperature switch was mounted on the upper radiator hose. Now the two electric fans work independently, each with its own switch. Using a relay, this new fan continues to run for some time to lower the temperature after the engine is turned off. With this modification we gain space, because the fan is much thinner than the propeller. The pressurization of the turbo to admission passes right there.
Yes and no. What this does is lower the temperature of the water in the radiator. What it doesn't do is lower the temperature of the water in the block/head, because there is nothing pumping the cooler water around the engine after shutdown. The effect is called "Heat Soak", and it can cause the water in the block to boil after shut down. On the Carlton, and specifically the Lotus Carlton, this causes the cylinder head gasket to fail, usually around cylinder #6. AIUI the other 24V Carltons can also suffer from cracks in the cylinder head valve seats to water jacket.
The Lotus solution was to include an auxiliary electric water pump which comes on when the engine temp exceeds 98 degrees. Unfortumatley they also included a 3 way valve to 'switch' it in/out of circuit, and this valve is vacuum operated. Leaks in the vacuum pipework mean the valve switches out of circuit so the pump ends up pumping into a dead end. This is the cause of many LC engine issues IMHO.
The engine looks like a 12V, so perhaps it's less of an issue than on the 24V/LC but before you go boosting it's probably worth monitoring the water temps around cyl #6.