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Author Topic:   cooling my motor with reduction pulleys.....
stockcar5
Dirt Full Roller

Total posts: 63
posted December 21, 2002 11:14 AM
what is the best ratio to use as far as reduction pulleys go. i have 25% reduction right now but i was thinking about going to the krc 15% reduction serpentine setup. i run about 200-210 but it will get up to 230 on a warm night. i'd like to keep it around 200 at all times. this setup will be in a stockcar on big 1/2 tracks with 355-383 motors 13.1 compression racing gas, 31" radiator and a team g aluminum water pump.

thanks

luke

KPLugnut
Dirt Freak

Total posts: 408
posted December 21, 2002 12:54 PM
1:1 ratio or as close to it as you can get, and no restrictor or thermostat. Straight water is fine and no antifreeze, but "water wetter" sometimes doesn't hurt.
For more info on the "why" questions I'm sure you'll have there are some good tech articles on the Stewart water pumps website.
I'm not sure of the URL of that site off the top of my head, but perhaps someone else can offer a link.
Running 230 is not uncommon due to your 25% reduction pulleys on a motor that has that much compression on gas.

Hope that helps.

KPLugnut

Scoot
Dirt Freak

Total posts: 330
posted December 21, 2002 01:18 PM
www.stewartcomponents.com go to Tech Support and it has 5 tech tips, very good info.

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Scoot
Smith Racing Team
870-365-5989

fastrack1
Dirt Full Roller

Total posts: 73
posted December 21, 2002 08:46 PM
I THOUGHT I WOULD ASK DO U RUN A SHROUD IF NOT U NEED TO THIS WILL PROBABLY DO THE TRICK IF U DONT U CAN GO TO THE SALVAGE YARD AND GET ONE OFF OF A 79-83 MODEL FORD LTD WITH A LITTLE JIGSAW WORK IT CAN MAKE A REAL DURABLE CUSTOM LOOKIN JOB IF THIS IS ON A CAMARO TYPE CLIP IT IS NOT A LOT OF WORK TO MAKE FIT ALSO WHAT FAN BLADE ARE U RUNNING

stockcar5
Dirt Full Roller

Total posts: 63
posted December 21, 2002 09:16 PM
i run a 17" fan (non flex type 6 blade) and i do have a full shroud. i run a plastic nose piece and do not punch holes in it for air flow to the radiator(dont like all the mud in the radiator). i do have a air dam below the radiator to funnel air up under the nose piece.

thanks for all the replies

luke

dirtbuster
Dirt Freak

Total posts: 353
posted December 23, 2002 09:41 AM
First off make sure your carb jetting is correct and you are not running lean. A lean motor will run hotter. I have seen lots of overheating problems cured by correcting carb jetting.

Without a shroud try to keep the fan as close to the radiator as possible leave maybe a 1/2" clearance. This will keep the fan pulling air through the radiator not around the sides of it.

With a shroud do you have your fan positioned correctly in the shroud. looking at the edge of the fan you should have half of the blades pitch inside the shroud opening and the other half outside the shroud.

Also If you can find one go to a 4 blade non flex fan. One with a fairly steep pitch as this will pull more air through the radiator.

I dont know what kind of belt system you run but make sure your belts are tight and that the fan wont slip. It may steal a few more HP but it will also make sure your fan pulls as much air as it can.

The air dam is a good idea and i have also seen guys that basically built a shroud in front of the radiator to help guide air into. The dam pulls air up from under the nose and then it gets funneled to the radiator by these shields on the sides of the radiator.


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