4x4Review Off Road Magazine
Summer’s 
here and it’s a relentless one at that. Old Mother Nature’s cranking up the global oven to a cozy broil. Bottom line, it’s just plain hot! Heck, Tarzan’s probably rethinking that whole fur thong thing he’s wearing right about now. At 220 plus degrees Fahrenheit, the innards of any V8 are probably thinking the exact same thing.
Here’s our situation. We’ve had an overheating problem in our Toyota Land Cruiser for some time and it just seems to keep getting worse each year. This year we decided to do something about it (finally). We tried about 5 different things and we’ll be telling you what actually worked, what didn’t work and more. From the mild to the wild, you’ll be in the know and your engine will be thanking you.
Here’s our setting. About 4 years ago we transplanted a fuel injected, Chevy V8 and a Turbo 350 tranny into da Cruiser. Keeping the OEM radiator that had been cored twice; we hoped that it would be enough. Initially it was, but after some time, and the installation of an aftermarket tranny cooler (one that bolts to the radiator) the motor would overheat at idle or during slow off-roading adventures. It seemed the V8’s standard-duty, clutch fan just wasn’t enough, so we swapped in a super-heavy-duty one. The swap was successful at keeping the rig cool, but the sound was absolutely deafening.
After a few weeks, we just couldn’t bear it anymore, so we figured the next logical step would be to install a high-performance, electric puller fan in place of the clutch unit. Our assumption was that the electric fan would 
move more air at idle than the clutch fan would, and at speed the amount of air moving through the radiator would cool the mill sufficiently. However, the advice of some of our colleagues proved true and it just didn’t work. We did like the small boost in power that we got from removing the oh-so-loud clutch fan and the fact that we could actually carry on a conversation without screaming was definitely a bonus. So, we found ourselves back to square one again and that leads us to where we are now… writing an article on how to keep your rig running cool. In this article, we’ll tell you about 5 tricks that you can do yourself to keep your mill running right at the suggested operating temperature.
In the following paragraphs, we’ll tell you what we did, if it was a mild or a wild fix, what kind of temperature savings we netted and the approximate cost for doing so. Each of the items and tricks we tested were performed in various settings to ensure that we could adequately measure a fair temperature change. Some tests required us to reinstall the OEM radiator while others required us to simply disconnect our electric fan. Overall, we feel that the measurements we gathered are as accurate as possible, but your gains or losses may differ for various reasons.
We’d also like to bring a simple fact to your attention. You can indeed over-cool a motor and a motor that isn’t running at the suggested operating temperature can not only lose power, but can also cause damage.
Step 1: Replace the aging, failing OEM radiator with a hi-performance one.
Rating: Wild
Approx. Cost: $460
Approx. Temperature Drop: 26 degrees
As we mentioned, our OEM radiator just wasn’t cutting the mustard. Albeit at one time in history a quality 4-core radiator, the seams were starting to leak once again and it just didn’t have what it takes to keep the mill running at the right temperature.
We placed a call into 1-800 Radiator (www.radiator.com) to seek their advice. We told them of our problems and that we were seeking a hi-performance radiator that would exceed OEM standards. Their cure. – An all aluminum, drop-in, hi-performance radiator made by Be Cool. That’s right… I said “drop-in”. 1-800 Radiator was actually able to find an aftermarket, hi-performance radiator made just for our Cruiser. For those of you who own vintage 4-wheel drives that aren’t Jeeps, you can probably appreciate the last sentence.
A few of you may be thinking that copper is a better conductor of heat than aluminum, so why would we switch to an aluminum radiator? The fact is that copper is indeed a better conductor of heat, but the other components in a copper/brass/lead radiator minimize its overall effectiveness and actually make an aluminum radiator 
much more efficient. The radiator supplied by 1-800 Radiator guarantees a MINIMUM of a 20 degree drop in temperature. Our results? A WHOPPING 26-degree drop! With just one component change, we were more than half way to reaching our goal of dropping 42 degrees in our overheating motor. Here are some details about the radiator.
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Guaranteed 20 degree drop over 4-5 row copper/brass/lead radiators
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All aluminum tank with a .080″ wall thickness provides superior strength
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Tanks are hand built, hand welded and 100% pressure tested
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Lightweight – Up to 40% lighter than copper/brass/lead (Our OEM radiator – 23 pounds / new radiator – 11 pounds)
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Compatible with all coolant types
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Average 35% lower price over OEM retail for universal Series radiators
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100% Made in the U.S.A.
Overall, the hi-performance, all aluminum radiator supplied by 1-800 Radiator gave us the greatest temperature drop of all of our components and/or tricks.
Step 2: Electric Puller Fan (replaced OE clutch fan)
Rating: Mild
Approx. Cost: $210
Approx. Temperature Drop: 5 degrees
Although we’ve labeled this as step two, we’ve actually had our Flex-A-Lite Black Magic puller fan in our Cruiser for over a year. Call it personal opinion, call it cool-factor, call it whatever you want, I personally just prefer an electric fan over a loud, horsepower robbing, belt-drive fan. That said, we contacted Flex-A-Lite ( www.flex-a-lite.com) and told them of our problems. They suggested a Black Magic electric puller fan (part # 165) that would move some 2,800 cubic feet of air per minute. That’s 2,000 more cubic feet of air than our OE clutch-fan at idle! Here are some details.
Although a clutch fan can move as much as 7,000 CFM, this is all dependant upon engine RPM. Fact is, you need most of your cooling at idle anyhow, so the 700-900 CFM that an average clutch-fan moves at idle doesn’t do a whole lot of good for a motor with overheating problems. Further, during normal driving conditions you can lose anywhere from 5 to 10 horsepower with an OE clutch fan.The advantage that electric fans have however is that they have maximum air flow at all times, so if the engine is getting warm, the electric fan turns on automatically and engine cooling begins instantly, before it gets too hot. Another benefit with electric fans is that you can manually turn the fan on if you anticipate a need for additional cooling, or off if you plan on doing some deep-water fording. Lastly, electric fans allow your motor to heat up faster during the winter months to get your tootsies warmer, quicker.
Step 3: Installing a hi-performance thermostat
Rating: Mild
Approx. Cost: $ 10.50
Approx. Temperature Drop: 2 degrees
I myself have always wondered if there was such a thing as a hi-performance thermostat. For me, putting those words together was a bit of an oxymoron and was like saying ‘hi-performance horn’, something better left to the JC Whitney’s of the world. We thought we’d figure out what all of the hubbub was about.
The truth is, there is such an animal as a hi-po thermostat and the two thermostats out there that seemed to have the best possible gains were a Stant and a Robertshaw. We replaced our el-cheapo $2.99 thermostat with both hi-po thermostats to see what gains we could get. Both thermostats offer precision temperature openings and slightly higher fluid pass-through than that of an OEM or aftermarket thermostat, which should allow for slightly better cooling.After swapping in both new Thermostats, we saw about a 1 to 2 degree temperature drop.
Note: Some unknowing people run their engines without a thermostat altogether thinking that they’ll reap the benefits of a cooler running engine. While the gains may be another 1 or 2 degrees in temperature drop, there is an inherent problem with doing this. Running without a thermostat keeps the engine from reaching its operating temperature by almost 4 times longer. This results in your engine having to work harder to move the thicker oil throughout the motor because the oil hasn’t reached its peak viscosity.
Step 4: A good old-fashion tune-up
Rating: Mild
Approx. Cost: $52.50
Approx. Temperature Drop: 3 degreesA good tune-up on a poorly running engine can net you gains of up to 7 to 8 degrees of a cooler engine. Our engine has been fairly well maintained but hasn’t seen a proper tune-up in about a year and a half. Proper engine timing will net you the greatest temperature drop, but the other components that go into a good tune-up will add up as well.
We started by replacing the spark plugs (and setting the appropriate gap), the air filter, fuel filter spark plug wires (hi-po 9 mm wires) and the PVC valve. For those of you with carburetors, setting the proper fuel mixture or richening it slightly can net you a gain of as much as two degrees or more. Since we’re running a fuel-injected motor, we don’t have that option so we spent some time making sure our timing was set accurately.
After our thorough tune-up, we saw roughly 3 degrees of temperature drop.
Step 5: Hi-performance, heat-dissipating headers
Rating: Wild
Approx. Cost: $300
Approx. Temperature Drop: 5 degrees
While most people think of headers as being a nemesis when it comes to heat problems, newer technologies are turning things around a bit. Typically, headers allow the hot exhaust gases to exit the engine more efficiently than a stock exhaust manifold. However, compartmental over heating problems typically occur with your average, off the shelf header. The thickness of the tube wall more often than not, isn’t thick enough to provide any thermal barrier so the tube gets incredibly hot, thereby completely baking anything touching or near it. Further, the metal most headers are made of are sub-par and will start to warp, crack and rust through very quickly. With a coated header however, you gain the benefits of the hot exhaust gases being able to exit more efficiently, and you get the thermalitic qualities of a stock exhaust manifold as well. With that said, you should expect to see a slight engine temperature drop with a set of hi-quality, coated headers.We talked to the folks at High Performance Coatings, Inc. (www.hpcoatings.com) and told them of our problems. While they didn’t have any firm data on temperature drops “inside” the engine, they make claims of as much
as a 30% reduction in under hood ambient temperatures and 50% (“HiPerCoat Extreme” coatings only) reduction in component skin temperature. Their no-leak, limited life-time warranty, block-hugger headers are coated with their patented, secret HiPerCoat coating process and provide superior corrosion protection, faster cool-down times and far superior compartment temperatures than others we’ve heard of or researched.Our High Performance Coatings, No-Leak Headers™ offer true 16-gauge steel tubes with 1-5/8″ tube diameters. The single plane hydra-formed merge collector is constructed of .090″ wall thickness, which allows for a maximum clearance in confined areas. The collector connection is a tapered, modular flange like OEM’s have utilized for years, which ensures a “No-Leak” connection to the 2-1/4″ down pipe (included). A SUPER Thick 3/8″, laser cut flange on each header attach the header to the head and prevent the flange from warping like most other off the shelf headers. Lastly, the High Performance
Coatings headers come coated inside and out with the HiPerCoat™ polished aluminum finish. (Eight other colors are also available.)Here are some other notable components to the HiPerCoat finish that you can expect.
- Superior corrosion protection; self-sacrificial quality will not allow corrosion to develop even when damaged.
- Lifetime guarantee against subsurface rust and corrosion.
- Performance gains from increase exhaust gas velocity, improved airflow, and reduced ambient under hood temperature.
- Rapid cool-down.
- Weldability.
- Color availability.
- Will not blue or stain.
- Eliminates thermal fatigue and oxidation.
- Excellent abrasion resistance.
- Protection at temperatures of -375°F to + 1,300°F.
- Can be applied to both new and used components
While our tests showed a 4-degree engine temperature drop over our OEM exhaust manifolds, we also noted an engine compartment temperature drop of nearly 45 degrees!
Step # What We Did Rating App. Cost Net Temperature Drop 1 Radiator – Replace stock unit with hi Performance, all-aluminum unit from 1-800 Radiator Wild $460 -26° 2 Electric Puller Fan – Replace OEM clutch style fan with electric puller fan (built in shroud) from Flex-A-Lite Mild $210 -5° 3 Hi-Po Thermostat – Install a hi-performane thermostat (test both Robertshaw and Stant) Mild $10.50 -2° 4 A good engine tune-up Mild $52.50 -3° 5 Replace OEM exhaust manifolds with hi-performance, heat-dissapating headers from High Performance Coatings, Inc. Wild $300 -5° Total Net Gains From Steps Performed: Total Approximate Cost: $1,033.00 -41° 1 800 RADIATOR 2990 Bay Vista Court
Benicia, CA 94510
Phone: 1-888-723-4286
Email: questions@radiator.com
Web Site: http://www.radiator.com/Flex-a-lite Consolidated P.O. Box 580
Milton, WA 98354
Phone: 1-800-851-1510
Fax: (253) 922-0226
Email: flex@flex-a-lite.com
Web Site: http://www.flex-a-lite.com/High Performance Coatings, Inc. 14788 S. Heritagecrest Way
Bluffdale, UT 84065
Phone: 801-501-8303
Fax: 801-501-8315
Email: hpcsales@hpcoatings.com
Web Site: http://www.hpcoatings.com/
