Cooling System V8 Datsun Z

A common problem with the V8 Datsun Z is overheating. In general, overheat due to insufficient air flow through the radiator, due to inefficient radiator designs. Some radiator designs restrict the air flow through the radiator. For example, a 4-row radiator is so thick, that an electric cooling fan cannot easily move air through a 4-row radiator. A 4-row radiator normally requires an engine-driven fan to draw air through the radiator.
For an engine-driven fan to work properly in the V8 swap, it needs a fan shroud. The shrouds shown on the cars in the introduction of this book are from a 1970-1974 Chevrolet Nova with a 350 V8, and the extension on the shroud is from a 1977 Monte Carlo with a 350 V8. The extension slides into the back of the Nova fan shroud and is held in place with staples, rivets, or screws. However, the shroud and extension are no longer readily available, and cannot be purchased new.
The most practical way to cool a V8 Z is with an electric cooling fan and a radiator that allows air to easily flow through the core, while transferring heat into the cooling air. Most modern cars use electric cooling fans, as well as radiators that allow air to easily flow through the radiator.
COOLING TIPS
On many engine swaps, the car overheats even though all the right parts are used. Often the overheating is caused by too much anti-freeze. Never use more than a 50% mixture of anti-freeze. A hydrometer (available at most auto parts stores for less than $10) should be used to determine the percentage of anti-freeze in the cooling system. As an example to the significance of anti-freeze on the efficiency of the cooling system, Chevrolet recommends using a 50% mixture of anti-freeze on S-10 Trucks in Canada, but only a 45% mixture for S-10 Trucks in America.
Some V8 Z cars overheat because the engine is poorly tuned for street driving. We have seen cars with aftermarket programmable fuel-injection overheat because the ignition timing was extremely retarded. In one case, the owner was running no part-throttle ignition advance— the car got horrible gas mileage, and it overheated. Running vacuum advance is important to prevent overheating.

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