Fan shroud

[shadowj38]

What’s everyone’s preference for a fan shroud with a 4 blade GM fan?

[MasterSbilt_Racer]

Home made...

[Jking24]

Theirs a ton of stuff out their but with so many different radiators and engine position differences. The best way is just to make something like masters said. Your gonna wind up cutting up whatever you buy anyway so...

[shadowj38]

What about the outerwear radiator protector? Any chance it can restrict air flow just enough to raise the temp a bit? I ran 225ish Friday night when it was about 75 degrees out. Just trying to get it to cool a little better before the air temp gets hotter in a few weeks.

[MasterSbilt_Racer]

What about the outerwear radiator protector? Any chance it can restrict air flow just enough to raise the temp a bit? I ran 225ish Friday night when it was about 75 degrees out. Just trying to get it to cool a little better before the air temp gets hotter in a few weeks.

I haven't noticed a temp rise.

[Mopar DLM]

Keyser carbon 4 blade fan 3/4" from radiator with no shroud. Up to about 80 degree days we run 1 row of tape to get it to stay around 200. All aluminium on dry sump with wire shaker screen and honeycomb on the front of radiator for protection.

[shadowj38]

I’m currently running a homemade shroud. Running without it was going to be the next this I try. I’m wondering if I don’t have it built to where it could potentially be causing turbulence and hurting me more than it’s helping.

[billetbirdcage]

Grab the fan and see how easy you can turn the fan without the motor turning, if so inspect pulleys if V groove the pulley is probably worn out and belt is running on bottom of groove and not the sides.

it should be extremely hard to get the fan to slip, I mean if you're pulling super hard and you get a little slippage your probably fine but if it moves with anything but a super hard pull with your hand you need to inspect to find issue.

Running that hot in mild temps shows a problem and it's not likely the shroud (unless this was some wide open throttle track and had a ton of dust to plug radiator)

[billetbirdcage]

I should note that most un-anodized V pulleys will wear out in about half a season as they are too soft, I could get maybe half a season out of a lower pulley before it was worn enough the belt no longer runs on the sides of the V. Anodized pulleys are typically hard anodized and have much better wear resistance and will last a long time.

If it's a serpentine system, the small diameter pulleys stink, there isn't enough belt contact for it to not slip on the water pump. Those ones that are under 3" or so diameter are worthless (IMO) and need to rap around the pulley at least 180 degrees worth to get any actual belt contact (IE need an idler if going to PS pump)

[shadowj38]

Belts pulleys and fan were all new at the beginning of the year. Less than 100 laps for far. Radiator was spotless and beginning of year. And even after inspecting after this last race, it was still pretty clean. I did clean it out and didn’t get much out of it.

[TheJet-09]

Are you cleaning it by running water through the fins, backwards? Just curious...about every four weeks or so, I remove mine from the car, hold it about a foot above the ground (face down) and drop it (onto concrete). I read that somewhere (Griffin maybe) as how to actually clean the debris out. I'm continually amazed at how much comes out (it usually takes about 5-6 drops total).

I also switched to the Gorsuch fan this year, and am quite impressed (although I haven't run in real hot temps yet). But many swear by them old GM fans...

[shadowj38]

On a weekly bases I run water through it from front to back with a garden hose when I wash the car. Then every 4 or 5 races I will pull it and mist hot water through it from a steam Jenny until it’s clean. I was also curious about the new 6 blade gorsuch fan but am a little afraid of plastic fans.

[shadowj38]

I run water from back to front i meant.

[riddle28]

id go up a couple jet sizes, it sounds like you have a good cooling setup as it is and with mild temps id be surprised to see it much above 200

[over4T]

Don't be afraid of the Gorsuch fan for being "plastic." It's a really nice piece made of a composite material and not anywhere near the old skinny cheapo fans. In a piece I wrote in the tech section a year or so back the Gorsuch was by far the best of any of several fans we tested.

Billetbirdcage also has a good point about worn out pullies that is usually overlooked. I think belt slippage is something many guys never consider.

Jet's mention of the old drop-the-radiator-on-concrete does get a lot of crap out but I still cringe when thinking about a light thin aluminum piece hitting the concrete and can't bring myself to do it. Used to do it regularly 30-40 years ago when they were brass/copper and a lot stouter.

The old half in-half out and as reasonably close to the radiator as you can get the fan still is best location in the shroud.

The hot part of the season is just beginning and I'm sure a lot of guys will be fighting the temps very soon. Hottest night we've had so far was high 90s and we ran 180 all night. Hope our luck holds.