Radiator Shroud questions

[cypher]

I am looking to purchase a new radiator with fan/shroud for an LS swap i have. During this looking for which radiator to pick, i notice some differences between the shrouds from different manufacturers and radiator vendors that has gotten me wondering what is the best design.
Some radiators have a shroud that covers the entire finned area of the radiator (or nearly the entire visible surface), while others leave gaps along the sides sometimes multiple inches wide, then others have brackets holding fans and nothing else. This doesnt even get into the fan differences or the little rectangle flappers that some radiators have (are these worth having?)
What is the best setup for a shroud to radiator?

What would you recommend as a good mid range priced radiator for an LS swap? Ive looked at tons, and have just gotten myself stuck on making a decision.

[badolds]

I like to get rid of the flex fan all together and go with an electric fan mounted in front of the radiator. Cleaner look and lots of extra room. The universal aluminum radiators are inexpensive and work great, the exact replacement ones are plug and play but expensive.

Dan

[dhutton]

The best shroud designs cover the entire core to prevent recirculation of heated air imho. Take a look at OEM shrouds and that is generally what you find.

Don

[CSG]

For best results:
Cover the entire finned area of the radiator
Use a puller style fan
Use a Very high CFM fan. The ones I use are 4500 CFM
Look into shrouds that have vents that will open at speed to allow air from the front that is under pressure to run through the radiator but shut at lower speeds (lower pressure).

[broken1234]

Examples of shrouds with fins? They are spring loaded, I guess?

[CSG]

Google "radiator shroud vents"
Most I see are a rubber flap

[marolf101x]

Most shrouds with "flaps" use these (or something very similar from a different manufacturer/supplier):
https://webstore.spalusa.com/en-us/p...dual-fans.aspx

[WallaceMFG]

The best setup is a shroud that covers the entire core with a puller fan. That way air is pulled through the entire core, not just where the fan is located. It also stops recirculating hot air from under hood which makes a drastic improvement in cooling. Pusher fans block too much airflow, there's a reason the OEM manufacturers don't use them often.

Flaps are not required, but strongly advised. On all of our new OEM shrouds the flaps are simple plastic doors. They are not spring loaded, the fan pulls them shut when it runs. That way they are free to open from air forced in at speed, but will shut when the fan spools up. They can be made from thicker (1/4") rubber and will achieve the same result.

When you live in a cooler climate you don't have to pay as much attention to cooling, hence the shrouds that don't cover the whole radiator or aren't even a real shroud that are cheaper to make. When you live in hot climates you cannot skimp on the cooling system, especially if you plan on driving the car hard.