to shroud the radiator or not shroud..................?

[BigLeo69]

with the f5r mk3.1 complete kit fan for the afco radiator, seems the velocity of the fan supplied is fine without the shroud, why do some use the shroud, and do you think its required?

getting ready to put everything back together again for hopefully the last time.

[Brian Z]

Most of our cars do not run a fan shroud. The afco radiator and fan supplied should sufficiently cool most engine setups. People usually will run the shroud from the mustang donor if they are building a base kit or if the have a radical engine which puts out alot of heat. Radical being 500+ horse power.

Best regards,

Brian @ FFR

[Magnus]

My fan in my Mk3 pulls from the back. I had some extra bits of shrouding put in because it seemed like the heated air was just recirculating over the top of the radiator. At speed it's not a problem but it matters in city traffic and back ups on the interstates. I've got 305fwhp.

[Todd Baumann]

Add the shroud, by doing this you pull air over the entire surface of the rad and not just the area that the fan covers without it. Especially when you are sitting still.
It will be much more efficient no matter what size engine and HP you are running.
As for the shroud Breeze has a nice one that fits the kit rad, all aluminum and $59. Nice piece.
HTH,
Todd

[Bob Cowan]

I agree with Todd. A properly installed shroud significantly improves radiater efficiency. It's cheap and easy to do, and there's no good reason not to install one.

[riptide motorsport]

i say shroud if possible..........Steven

[CapeCoralCobra]

Because of the very warm weather here most of the year, I used a donor shroud and the Breeze shroud add-on that seals the area between the 3/4" horizontal at the top of the radiator and the underside of the body in front of the hood. This way, all the air that enters the front opening must go through the radiator. There is no other escape for it.

[Jeff Kleiner]

I'm with Todd, Bob and Steven. Used the Breeze shroud on two cars; better cooling at low speed and you can't beat the price.

Jeff

[Jim Schenck]

I am of the opposite opinion on the shroud, but only in the specific case of the roadster. The fan has a built in suround so when it is mounted against the radiator it will pull air through the a section of the radiator equivalent to its entire surface area, plenty to cool the engine at low speeds. At higher speeds (above 35 mph) the fan is no longer making air flow faster but it becomes a restriction, these are also the speeds where you will be using more power and need more cooling. Adding a shroud on to the fan means that all of the air flowing through the radiator is now subject to this restriction and cooling becomes less efficient. Because of the shape of the nose opening and the massive amount of air it allows to hit the front of the radiator this is a specific case to our particular car. In the cars we race we often won't run a fan at all, they are seldom run at low enough speeds to need it and the cooling is better at high speeds without the fan in place.

I am also not a fan of sealing from the top of the radiator to the body, doing so creates high pressure and lift in the nose of the car and in almost all cases the extra air is not needed for cooling.

[Rootbeer Roadster]

I am of the opposite opinion on the shroud, but only in the specific case of the roadster. The fan has a built in suround so when it is mounted against the radiator it will pull air through the a section of the radiator equivalent to its entire surface area, plenty to cool the engine at low speeds. At higher speeds (above 35 mph) the fan is no longer making air flow faster but it becomes a restriction, these are also the speeds where you will be using more power and need more cooling. Adding a shroud on to the fan means that all of the air flowing through the radiator is now subject to this restriction and cooling becomes less efficient. Because of the shape of the nose opening and the massive amount of air it allows to hit the front of the radiator this is a specific case to our particular car. In the cars we race we often won't run a fan at all, they are seldom run at low enough speeds to need it and the cooling is better at high speeds without the fan in place.

I am also not a fan of sealing from the top of the radiator to the body, doing so creates high pressure and lift in the nose of the car and in almost all cases the extra air is not needed for cooling.

A post like this from Jim is the reason this forum is better than the other one. Thanks for your participation and this section of the forum. I already have the Breeze shroud based on other advice, but won't bother with the top piece. Thanks again.

Jeff

[BigLeo69]

yep a quick answer, and different views
i would think that if the fan failed and you had a shroud it would become an issue

[Mustang Man]

The best of both worlds would be a shroud with relief flaps in it, like the Spal dual fans I run in my Mustang. They cover 100 percent of the core and at speed the rubber flapper/doors (four top and four bottom) pop open to relieve the pressure between the core and the fan blades. My Mustang stays ice cold with a 450hp 347ci stroker.

Now if I can just get the Roadster to cool better! I think my issue is needing a lower thermostat (just dread cracking the cooling system open) and a larger overflow tank that has enough capacity to not suck air back in when the car cools...

Mark

[rich grsc]

So how many factory cars are running around without shrouds? There are numerous threads with overheating issues where a shroud solved the problem. I have never seen one where removing the shroud fixed it. Leo, you can put the car together and drive it to see if its a problem. Then take it apart an install a shroud if it is, or spend a few $ and just put it on now, and never look back.

[Jim Schenck]

Factory or OEM cars are a different story, they design small air inlets to minimize drag for fuel economy and rely on the fan to pull the extra air in. In our case with the large nose opening we have the opposite problem, we can get all the air in we need, but to be the most efficient we don't want to restrict getting it out.

[BigLeo69]

i will run it with out the shroud for now just thinking ahead, thanks rich
and Mark i found that the 180* stat was doing better for me, this was just on engine fireup but the 195* seemed to get the engine too hot.