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Author Topic:   Radiator fan spacing
Rusty93
Dirt Full Roller

Total posts: 44
posted September 02, 2003 09:28 PM  
How far should the fan be from the radiator? I have a shroud and a 4 blade 300 ford 6 cyl fan. My car is running fairly hot. It's getting to about 240. I tried a six blade fan, but it was worse. I also have a 3/4" restrictor in the thermostat housing. Thanks in advance.

nate 11
Dirt Freak

Total posts: 316
posted September 02, 2003 09:34 PM  
is the fan sticken about 1/2 way into the shroud?

Rusty93
Dirt Full Roller

Total posts: 44
posted September 02, 2003 10:04 PM  
quote:
Originally posted by nate 11:
is the fan sticken about 1/2 way into the shroud?

Yes, thats about right, but it's a homemade shroud. About 3 " deep

ruggs66
Dirt Maniac

Total posts: 193
posted September 03, 2003 01:00 AM  
try distilled water & check your timimg at total advance.

[This message has been edited by ruggs66 (edited September 03, 2003).]

powerglides
Dirt Freak

Total posts: 374
posted September 03, 2003 06:35 AM  
Take out the restrictor, and drive your water pump 1 to 1 ratio do not underdrive it. These two things lowered my water temp 40-50 degrees.

Speedway65
Dirt Freak

Total posts: 344
posted September 03, 2003 09:30 AM  
What do you put in place of restrictor?

sideways
Dirt Forum Champ
Total posts: 715
posted September 03, 2003 09:11 PM  
Nothing run open t stat housing.It will run more flow through.I dont agree with the whole restrictor bit.But I have seen people use it.I dont but some do and to each there own. just my two cents

Rusty93
Dirt Full Roller

Total posts: 44
posted September 08, 2003 10:00 PM  
Thanks guys. I will try that in a couple of weeks. I had to take a break, got married last Sat. Going on the honeymoon this weekend.

FastEddy
Dirt Full Roller

Total posts: 53
posted September 08, 2003 11:20 PM  
Congrats!!!!

waltonjr1
Dirt Forum Champ
Total posts: 516
posted September 10, 2003 08:15 PM  
If you dont use a restrictor,the water will not have time to cool.I have never heard of anyone running no type of restriction.

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DEANJR#22

ryan
Dirt Forum Champ
Total posts: 776
posted September 10, 2003 08:56 PM  
No restrictor for me with a stewart pump runs 190 in 90-100 degree weather.

ratracer10
Dirt Maniac

Total posts: 141
posted September 12, 2003 01:58 PM  
Now you've heard of two. No restictor, no problem cooling.

AC156
Dirt Freak

Total posts: 377
posted September 12, 2003 02:10 PM  
we tried a restrictor one time and ran hotter with it. took it out and ran 190-200 deg.

BIGDADDYBOZ
Dirt Freak

Total posts: 466
posted September 12, 2003 06:14 PM  
I tried runnin with out a restictor and ran hot! Knocked the center out of a thermostat and 190 after the feature!

waltonjr1
Dirt Forum Champ
Total posts: 516
posted September 12, 2003 11:14 PM  
I guess whatever works best for you run it!

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DEANJR#22

SLEEPY GOMEZ
Dirt Freak

Total posts: 295
posted September 14, 2003 01:32 PM  
The purpose of running a restrictor at the water neck is not to slow the flow. It is to raise water pressure in the heads so as to prevent steam pockets. Steam is a vapor and doesn't transfer heat like water. The restrictor is often necessary when using a stock or generic racing water pump. The Stewart pump has such a high flow rate it raises the pressure in the head without a restrictor. Howard (Stewart) told me you can't move water through the radiator too fast. SLEEPY

waltonjr1
Dirt Forum Champ
Total posts: 516
posted September 15, 2003 04:10 PM  
If you cant move the water to fast why use reduction pulleys on a racing high flow pump that should handle the rpm.I understand a stock pump will cavitate but wouldent you be defeating the purpose slowing down a stewart pump if this were true?What if you were to run no reduction pulleys on a stewart pump with no restrictor?Would this be the way to go?Help me out here,not being sarcastic.

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DEANJR#22

AC156
Dirt Freak

Total posts: 377
posted September 24, 2003 12:54 PM  
quote:
Originally posted by waltonjr1:
If you cant move the water to fast why use reduction pulleys on a racing high flow pump that should handle the rpm.I understand a stock pump will cavitate but wouldent you be defeating the purpose slowing down a stewart pump if this were true?What if you were to run no reduction pulleys on a stewart pump with no restrictor?Would this be the way to go?Help me out here,not being sarcastic.


go to www.stewartcomponents.com and read the tech tips. he does not recommend running underdrive pulleys.

RC Racing
Dirt Freak

Total posts: 236
posted September 24, 2003 02:35 PM  
just from my experience...

Had a Stewart StageII on my Limited Late Model (12:1 compression, 550+ hp) car.

Per Stewart tech support, do NOT run a restrictor.

Currently using that same pump on my 9.5:1 pump gas, "maybe" 375 hp motor Limited modified (supposedely these cars are notorious for running hot). Usually runs 180 to 190 during the races (20 lap feature).

You'll make the final decision, but it wouldn't hurt to do a simple test but obvious test(regarding the restrictor): take it out, run the heat and see how it reacts.

As far as fan placement, have the 4-bladed fan as close as you can to the rad, but maintian a placement where at least 1/2 of the fan is not shrouded (and I advise against using a 6 blade)

One last question: when's the last time you cleaned the raditor? I don't mean flushed it, but actually removed it from the car and made sure the cooling fins aren't clogged with mud (easiest way for me is to turn it horizontal, hold it about 6" over a piece of plywood, and then drop it a few times. The dried up dirt will fall out)

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nate 11
Dirt Freak

Total posts: 316
posted September 24, 2003 06:22 PM  
why not a 6 blade fan?

Flanndad
Dirt Freak

Total posts: 255
posted September 25, 2003 06:40 AM  
I just switched from a 6 blade to a 4 blade off of a 67 suburban.

Someone told me when it is spinning fast it turn's into a wall, and won't push enough air past. I wasn't sure if I believed that, but when I first started it up I wish I would of had my safety glasses on.
There was more air being pulling through.
Also the 6 blade was 15" and the 4 blade is 17 or 18"'s.

Hey Rusty93 go to the engine section, down about 10 post, see GETTING HOT - NEED HELP, and you can read my post.

Check Items to follow:
1. Check Spark Plugs, not running lean
2. Check Timing with the car Revved up.
3. Shroud good and tight. With plastic between nose and radiator, no place for air to go except thru radiator.
4. Plenty of air holes in grill
5. Air**** under radiator
6. 1" restrictor, or gutted thermostat
7. Make sure there are no intake leaks.
8. Are the belts tight.
9. I put some light vertical grooves on the pulleys to prevent slipping, with die grinder
10. If using head studs make sure they are not leaking. No little bubbles in radiator.
11. Flush system good, Refill with Distilled water and water wetter.
12. When filling system back up start vehicle, jack the front end up, get radiator high let run for a while and then top of system. This should get out all trapped air pockets.

This is the stuff I learned on this site, and last week my car went from 235* to 155* after my race.

[This message has been edited by Flanndad (edited September 25, 2003).]

bigcitycowboy
Dirt Forum Racer

Total posts: 89
posted September 29, 2003 01:17 AM  
even with the distilled water, still add water wetter??? i heard not to add anything to the distilled water, cause it would contaminate the water, defeating the purpose of distilled water??? ????? just wondering

Flanndad
Dirt Freak

Total posts: 255
posted September 29, 2003 06:20 AM  
I'm not sure either.
But one of the above items or the combo, helped take down my temperature 80*.

I'll be the first to tell you I understand motors, but don't know much about them either.

bigcitycowboy
Dirt Forum Racer

Total posts: 89
posted September 29, 2003 04:49 PM  
i also got a question.....with a high flow water pump, do u want to rum it 1 to 1, or underdrive pulleys???

Rvarc
Dirt Roller

Total posts: 7
posted October 02, 2003 11:24 PM  
You use distilled water because it doesn't have all the crap in it that gums up the rad and block with mineral deposits.The water wetter is to lube the water pump seals to keep it from wearing out.

powerglides
Dirt Freak

Total posts: 374
posted October 03, 2003 09:12 AM  
Just use a can of water pump lube from auto parts store, and water. NO additive has ever been proven to lower water temp.

Speedway65
Dirt Freak

Total posts: 344
posted October 03, 2003 12:37 PM  
acoording to Stewart you run the pump 1 to 1

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