I'm not trying to start an argument here, but there's simply too much bad information on this thread...
First, the Spider cooling system works very well. Even in extreme temperatures the needle stays right in the middle. Furthermore, the components found in an Alfa Spider’s engine bay are of very good quality. They last years and years. I’ve been a continuous Spider owner since the mid seventies, and I have never had a fan explode. The three Spiders in my signature are current cars and serious transportation. They go from OH to NJ at a drop of hat. The ‘84 even pulls a little trailer and goes on the track at the Alfa conventions, and its air conditioning will freeze one out of the car.
It is not difficult at all to return a Spider back to spec and have a system where the engine and attached fan are properly aligned with the radiator and attached fan. However, at professional Alfa mechanic rates, even a few hours of work will amount to several hundred dollars. The more neglected the engine bay, the more parts that have to be replaced and the longer it takes to re-do things the right way.
The Bosch and other European parts found in the Spider engine bay are not cheaply made, but by the same token, they are not cheap to buy. In fact, they are much more expensive than any aftermarket part. It is understandable that an owner always looks at cost, and if it weren’t for the aftermarket parts some of us would not be able to afford to keep a Spider running. Regardless, installing an aftermarket electric fan is not an improvement. At best, one will simply be able to reproduce the rock steady needle in the middle that the stock set-up yields.
If one is holding the accelerator pedal all the way down to the floor, and suddenly the load of the mechanical fan was removed, one would experience a performance gain proportional to what it takes the engine to spin the fan. However, since one doesn’t drive on the street with the accelerator pushed all the way down, all one needs to do to get more out of a Spider on the street is to push the pedal down a bit more. Similarly, while it makes sense for a racer to remove any engine load that allows him to rev the engine quicker and gain just a few 100ths of a second, this simply is not something that anyone will perceive while driving on the street.
The usual US Alfa suppliers carry aftermarket electric fan units that fit our Spiders. They have done the work for us and one can be assured that the set-up that they are selling will work. Nonetheless, the installation is up to the owner. It is possible to install the electric fan with plastic ties that are laced through the radiator fins, but this is not the way any car manufacturer would do it. The alternative is to fabricate brackets, which is a much more involved proposition. It is up to each individual to decide on the level of work one wants to put into his vehicle. By comparison however, it is not a bad idea to see how the Alfa factory did the electric fan conversion. For that, one has to look no further than into the engine bay of a 1990 or later series 4 Spider. Starting in said year, Spiders were fitted with dual electric fans. The whole set-up is a bit different than a typical aftermarket installation, but then, the OEM set-up carried a warranty a bit longer than the 30 days that come with the aftermarket parts.
I’m not saying that there is anything wrong in choosing to install an electric fan to replace the original mechanical unit. In fact, I had an electric fan fitted into my ’74 Spider. At that time the mechanical fan was over 20 years old, and while I wasn’t having any issues, I thought it prudent to consider replacing it, since I know that even good parts don’t last forever. I do think it is fun and cool to have the electric fan out of sight, in front of the radiator, while opening up the space in front of the engine. This mod however, is cosmetic, and since I had mounting brackets made, it was more expensive than simply replacing the OEM plastic fan.
Best regards,
