Radiator perpendicularity to airflow, how important is it? Options

[bondo]

I'm working on radiator placement, and wondering if it's super important to mount it vertical. I know tilted radiators have bene done in 914s before, but they're usually very large radiators that wouldn't fit if standing straight up. It seems like some angle off perpendicular might improve cooling by introducing turbulence within the radiator? Too much and obviously there'd be a disadvantage. Do any manufactured watercooled cars have a tilted radiator? Seems to me I saw an RX-7 once that did. I know that the intercoooler on our WRX is pointed nearly straight up (with a scoop directing air downwards into it) and way more bugs hit the back half than the front, presumably meaning most of the air does too.

I figure that at worst I'd lose some effectiveness at cruise, because if the car is not moving, there is no airflow to be perpendicular to. Do most 914 V8s that have cooling problems have them at cruise or at idle?

[jsteele22]

Sounds like good advice. Think of it more in terms of a pressure difference than as wind. My hunch is that the uneven distribution of air flow (and bugs) doesn't have a huge effect. Just means that heat is removed more rapidly from some spots, less rapidly from others. (Of course, removing the bugs will surely help !!!)

I think that, in rough terms, making air change direction isn't too detrimental, but anything that causes turbulence (like sharp turns, abrupt changes in duct size, etc.) will cause less flow, and possibly stagnant zones (eddies).

BTW, what do people make their ducting out of ? Sheet metal ? I was thinking it might be fun (possibly even worthwhile) to try fiberglass. Make a space-filling model of the volume using some kind of packing foam, styrofoam, Great Stuff,etc., cut and shape w/ a hot wire, surform, knife, ... and then lay on the fiberglass. Prolly a lot more work, but I imagine it could be made to look really nice. And then you don't just have a duct, you've got a product....

Also, FWIW, I can't be sure, but I think I heard that on Corvettes (no grille) the radiator is close to horizontal, and the air comes in from below via a scoop, and is drawn back out by a backwards scoop. Anybody know for sure ?