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Will adding 1 inch to fan spacer make a difference?

8900 Views 8 Replies 7 Participants Last post by  001mustang
I've read the suggested distance from a fan to the radiator should be about 2 inches. Right now, with a shroud and a 2 inch spacer, I've still got close to 5 inches from the blade to the radiator. Looks like the max spacer I can find is 3.5 inches, but will adding only an inch or so really make a difference?

Another suggestion is also a long water pump, but then I have to change brackets as well. Any other inexpensive suggestions?
58 chev, 383 stroker.

Engine is running around 202-212 during idle, radiator is cooler at bottom than at top according to spot laser temp gauge. Car has not overheated. Tstat seems to open annd close properly. Have not looked but could be 195 deg tstat.
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As a rule of thumb if you look at your fan and shroud the fan blades should be about half way into the shroud (half the blades showing outside the shroud and the other half inside the shroud) . It dosn't matter how far the fan is away from the radiator When Your Using a Shroud.
Anyother thoughts on this guys ???
That sounds perfect to position fan 1/2 way into shroud. The fan should be pretty effective so long as it is any where in the shroud. I removed my shrouds because they are a pain to work around and to look at. I position unshrouded fans as close to radiator as feasible.

Before repositioning fan I would first see if fan adequately cools radiator in hot stop and go traffic; if it cools adequately then I would not reposition fan.

Of course electric fans are an option if you can't position fan correctly. Remember that it is common for an electric fan to produce lower SCFM than its mechanical counter part. Sometimes you have to run two electric fans.
Yes, it is a flex fan! Should it be a fixed?
lazydawg said:
Yes, it is a flex fan! Should it be a fixed?
You should run a clutch (thermal) fan. They are more efficient than a flex fan.
Does the temp go down when you hit the freeway or start moving?
What size fan is in there now? I run the biggest mechanical fan that I can get in the shroud and still leave about 3/4" clearance from the fan blade ends.
You might need a better waterpump, or some water wetter like 40 below or that redline additive.

Like the others said, if the fan is 1/2 way in the shroud ,that is plenty.
Later, mikey
The mechanical fan/shroud set-up if done right should work for you. What type and size radiator now? What size fan? How much room from fan to shroud? Is the shroud a full shroud, set up to draw from the entire radiator? Once up to operating temp, when cruising, what temperature? How big is the radiator (capacity, 2 3 or 4 core)? Is the front of the radiator obstructed at all? One some cars, it is just easier to mount an electric, or dual electric. I tend to agree with the biggest possible, and am aware that some don't want a big old fan. Some of the flex fans, or molded fans work okay, but not like a good steel fan. There are primitive looking four blade fans that will oftentimes work better than a 6 blade flex or molded type. Sometimes you have to switch or modify to keep it cool, as you seem to be finding out. Are youo running a trans cooler if using an automatic, and if so, is it routed throuht the radiator? You might want to consider the addition of a trans cooler if not using one now. What type of water pump are you using... stamped or cast impeller, hi-flow vs reg, where is the t-stat housing - higher or lower than the radiator top? This ought to keep you occupied for a minute.
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Infrared Temp measurement

To maximize consistent results while using an IR temp gun you can place a piece of black electrical tape at each spot you wish to collect temp data. This will help normalize emissivity for the IR gun.

Just in case you want to double check your temps; which are within spec on some cars.
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