I just got back my radiator being redone and this guy tells me that you need a "pusher" type fan on this?? I have twin spals that are on the inside that pull air thru. That seems more reasonable than a fan blowing back thru the radiator thru the grill?

Any way...question?


Michael

In theory you should get better heat transfer from the same fan with a pusher because it creates a high pressure zone over the fins on the radiator. High pressure air transfers heat better than normal or low pressure air. The converse should be true with a puller fan, as it creates a low pressure zone around the fins of the radiator, so heat transfer should be lower.

About the best thing you can do is put a proper shroud on the fan so that it can push air through the whole radiator, just strapping the fan to the radiator is going to cool worse than a fan with an air gap and a proper shroud.

if air flow doesn't move thru the rad. [like a car moving down the road] ... yes a pusher is the way to go, but since the car is moving and air is flowing thru the front and thru the rad the last thing you want to do is limit the fontal area of the rad with a full shroud it limits the free air flow. this is why in automotive aplications pullers are better

Michael, if you'd like some pictures of a good setup ( this one is a puller with a nice shroud ) on a 914 I've got a car here I can take some pics of.

Troy raises a good point that the overall design is more important than the smaller aspects like push vs. pull.

http://www.914world.com/bbs2/index.php?sho...=33301&st=0


early on in my build thread I have some decent pics of how I made a shroud for a dual puller setup.

good luck.

Chris, by all means, please show me the pics!!!



Michael

Hey Michael,
I am all for a puller. I gotta say with my renegade radiator my fans hardly even come on. The air flow up front is so good It doesn't get hot enough for the fans to go on. Unless I am in stop & go around town. Still fans come on around 190 & it never goes above that. I love this setup . So I think a shrouded radiator with a puller setup is the way to go. Isn't that how you had it setup before?

I'm uploading the original photos here, lemme know if you have any trouble viewing them. This setup was installed by renegade.

http://hamiltonracing.net/photos/v8radiator/

Nice set up you have there. The key is to get the hot air out of the trunk. Therefore, inlet size should be smaller than outlet, it needs to draw and that's why pullers usually work better.
If it can't draw and there is no shroud, air can re-circulate back, or forward throught the unshrouded portions and then back through. With the proper sized inlet and exit areas your set up should work just fine as there is very little area not covered by the fans.
I've used a regular camaro radiator for over 20 years with a home made shroud and two Japanese 12 fans on a 300+ HP V-8.

One of the V8s I had in the past had a puller on the backside and a pusher on the front side. They worked independent of each other.

Jamie has got THE setup, Renegade with the fans and the shrouding.
Well worth the money spent.
CCLIN2008ISTHETIMETOV8

Jaime,
Thats what I have but I worry every time the temp gauge goes over 180 degrees. So my fans come on at 180 and it bothers me...maybe I worry too much but I think my problem is the outlet hole size...everyone else has over twice the area that I do...

Michael

Unless you are going over 200 with regularity I wouldn't worry. I could probably set mine to go on lower but when it doesn't go higher than 190 I don't worry. Of course I was used to mine hitting the 220-230 range & not being able to drive it very long. So I feel spoiled now.