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Coolant System

Coolant system


This section concerns a 16v engine conversion in an AlfaSud series car.

Three issues had to be addressed for the engine to fit and function correctly.


Radiator Fan


The biggest problem was that of the coolant fan not fitting, due to a serious foul between it and the no 1 and 3 cylinder cam belt cover. The metal fan ducting and support assembly has three spoke supports, with a central boss that carries the fan. One of these supports, plus the central boss overlap with the belt cover, prevents the fan housing from sitting low enough.

It is possible that there is an aftermarket fan available to fit into the space, but I did not investigate this very far. The later Alfa 33 plastic framed fans do not work, as I tried one for size and found it suffered in an identical fashion to the metal framed unit.

To cut a long story short, I modified the metal fan support frame to allow it to better suit the new installation. Follow the steps shown below, and you shouldn't have a problem, as this gives considerably more clearance for not a lot of work.

Fan premod.jpg (27261 bytes)

This picture shows the original configuration of the fan frame, and the areas most likely to foul. The three supports are not equidistant, with the bottom two being spaced more widely. This gives the chance for the support structure to be modified.

fan frame cutting.jpg (62137 bytes)

The fan spoke supports must be cut away from the duct and shroud, as per the picture above. A nice thin cut will ensure that the front to rear position of the fan blades is not affected. The fan motor is easy to remove, and you must remove the three grommets too.

Fan pieces.jpg (29925 bytes)

As well as cutting the frame, a small reinforcement strip was made from 2mm thick sheet (actually an old piece of 'Sud suspension arm was cut to make it!), and then bent to fit inside the support frame.

fan weld.jpg (94478 bytes)

The support frame was then welded back onto the duct assembly at the new angle, about 30 degrees anticlockwise, and the reinforcement strip welded inside the frame itself.

fan frame modd.jpg (138518 bytes)

Once all was welded, I dressed all the welds with a rotary grinding stone, and smoothed all the edges off. I also dressed a segment adjacent to the reinforcement strip to gain some extra clearance. I also drilled some new mounting holes, which moved the whole assembly up and away from the cam belt covers. The whole lot was then primered and painted black.

finished fan.jpg (26323 bytes)

Once it was all re-assembled, the whole assembly looked good, in fact if you didn't know you'd think it left the factory like it. As you can see, the results speak for themselves. The clearance gained was substantial, and there is no danger of the fan ever touching the engine in normal operation.


Coolant hoses


The bottom radiator hose outlet on my 16v is the same part as was fitted to my 8v 1.5 engine, and fits in an identical fashion. Unfortunately, the larger heads of the 16v mean that the standard bottom hose will not fit straight on, as it would be bent sharply over the head

bottom rad hose area.jpg (103933 bytes)

RAD LOWER HOSE ON.JPG (31335 bytes)

To get around this it was necessary to modify a 16v lower hose, by cutting it and inserting a length of 32mm diameter copper pipe. This allowed the hose to go up and over the area or the head that caused the foul.

rad bottom hose detail.jpg (122938 bytes)


The last area of concern was around the throttle linkage area under the throttle body on the left hand side of the car. The coolant header tank return hose from the heater was found to be too close for comfort. A little fiddling around with similar diameter hoses and some metal pipe of the correct size allowed the routing of the pipe to be changed slightly, gaining extra clearance.