Technical Shroud or no shroud?

I had been running a 16 inch electric puller fan on my 58 Ford truck mounted directly to the fins (no shroud).

Then I decided to adapt that fan to a shroud that I had, but I'll be darned if I don't seem to get as good of cooling as I did when that electric fan was just attached to the cooling fins of the radiator.

Maybe because the air (at speed) would flow through all parts of the radiator before but the shroud could be restricting flow at speed?

What are your thoughts?

 

Why did you add the shroud? There must have already been a cooling issue?

 

I just had it laying around and thought I might see if there was an improvement.

 

Shroud helps but don’t get the blades to deep in the shroud. Fan just in side shroud gives best air flow, I’m thinking 1/2 inch but somebody will give us correct depth

 

I’ve found the best shroud to mount a puller electric fan is a 1” deep cookie baking pan. Some are sectioned others are widened by using 2. I use a split fuel hose for a seal on the edge to the radiator core. The fan then sucks thru the entire core. I buy them at a kitchen/restaurant supplier near my home.

 

I have never ran a shroud on any of my builds, one of them being a 548" BBC that ran 9.63 at 141 on pump gas no power adders. Spal 16" fan.

Always ran a spal 16" puller fan or on one car twin 11" spal fans. No over heating. The airflow thru the radiator is so fast if you turn the fan on and place a piece of cardboard in front of the radiator it will slap the cardboard HARD, so much easier to work on a car without a fan shroud. I mount the fan within 1/2" of the radiator.

 

Blade should be 1/3 in the shroud 2/3 out.

 

Don't fix what aint broken.

 

I added a shroud to my '63 Falcon gasser with 468 BBC in an attempt to make it run cooler idling at stop lights. It made the engine run hotter at all speeds, even though I used the same electric puller fan.
I determined two things. The shroud was first too close to the radiator, and second blocking off the corners that used to be open. I had to stop on my first test drive and remove the shroud so I could get home without overheating!
I put the fan back on the core and it ran as before. But still had issues overheating in traffic jams. I decided to borrow and air/fuel ratio gauge and tested my exhaust. My tunnel ram with twin Holley 600's was running much too lean, so I began removing jets and drilling them out about 6 sizes larger. Reassembled the carbs and checked the air/fuel ratio and it was 14.5 so I stopped there.
After enrichening the jet sizes the car never overheated again! I could idle in 100 degree temps for 30 minutes and never went over 190 degrees.

 

Pictures of the installation? Hard to spot mistakes if they aren't shown or described.

 

Look at OEM electric fans. I can't remember seeing one without a shroud and they don't spend a dime without it having a benefit.

jack vines

 

Depends on the shroud design. I have seen shrouds that actually seem to block airflow through the area of the rad surrounding the fan.

 

Maybe he was trying to protect his radiator from damage.?

 

Look at 88-96 grand Prix, Cutlass and regal, 95-01 lumina, and 95-99 monte Carlo. No shrouds on those.

 

Could also be a sign your fan isn't quite high enough cfm