If you want to install your electric fan and shroud, then follow this simple guide. Now that you bought yourself an electric fan and shroud many people take the easy way and use zip ties to go through the fins of the radiator and tie the shroud together. Technically this can and has worked but its ugly, lazy and leaves much to be desired. Eventually the straps will rub the much-needed radiator tubes and cause a leak. Only use this in an emergency if something breaks or a situation comes up that its called for.
With a bit of space between the fan and the radiator, a fully shrouded core gets full flow through the entire area, yielding fare better cooling effects. You don’t want the shroud to sit up against the core too closely. The bare minimum is ½-inch, but 1-2 inches is the recommended spacing. You need this space to allow the core to flow air properly. Above 40 mph the fan actually no longer needs to do its job as the natural air flow of speed takes over. If the shroud is too close to the core, it becomes a restriction, and the air can’t pass through. You will need an inch of space for the proper heat exchange to work and be effective.
You can fix this by adding a pusher fan in front of the stack to push more air through the cores. Using both a full-size pusher and puller fan is not recommended, as this can cause lower air flow, but in certain situations a pusher can assist a puller fan. For example, a vehicle has a 24” x 8” tall intercooler in front of a 16” x 12” AC condenser, then a 12” x 12” transmission cooler, all stacked in front of a 28” x 18” radiator core. In this case, the radiator has the best flow across the top 12”, decent flow across the center 8”, and then fairly restricted flow across the lower 8” where all four exchangers are stacked. A puller fan will draw through the entire stack up, but air always flows through the path least resistance. The AC condenser isn’t getting the best flow, reducing the AC output, the transmission cooler is stuck between the other three, so it gets the hottest air flow, reducing its ability to cool the transmission fluid (another reason for an in-tank AT cooler). The intercooler gets the cool air first, but the stack up behind it creates a lot of backpressure, reducing the air flow, and the depth of the stack allows a lot of air to simply bypass the intercooler altogether.
Using a couple of 8” pusher fans in front of the intercooler in the above scenario helps move more air through all the cores behind it, compensating for the lower pressure areas of the core that is less restricted Everything works better in this case. This is also the one exception for fan shrouds. A pusher should not be shrouded, as the shroud will restrict air flow to the core when the vehicle is at speed. A shroud behind a core that is only using a pusher fan is an unnecessary restriction as well
Do not use zip ties to tie together the radiator or the shroud or in time it will ruin the radiator cores. Use fan rings to secure the shroud to the radiator and leave a half inch. Four of them should work fine. Don’t risk damaging your radiator with inferior zip-tie straps, always mount your cooling fan properly with fan rings and use a good seal between the fan ring and radiator if not using a shroud.
