Oil & Cooling System

OIL & COOLING SYSTEM UPGRADES

OIL SYSTEM:

On stock 5.0L and 5.8L motors, the oil filter is located on the driver's side of the block near the front accessory drive. With an oil filter in the stock location, it will not clear the Ranger's steering box, no matter which filter you use. The solution is to install a remote oil filter and adapter that will route the oil around the steering box. I also like this setup because it allows more convenient location of the filter as well as easy installation of an oil cooler (if desired). The oil filter adapter is available from several sources, including L&L Products (part no. 040184), Kaufmann Products (part no. not available), and Total Performance (part no. 83/RB 6881). The adapter installs just like an oil filter on the block (be sure to use a light coat of clean motor oil on the rubber gasket), while the remote filter can be mounted almost anywhere.

Oil filter adapter just barely clears steering box

In my case, I mounted it to the front bumper brace in the driver's side front wheel well for easy access. When mounting the filter, make sure that you have sufficient clearance for the wheels and tires to cycle through their complete range of motion (check with a properly-sized tire mounted on the truck). It also makes changing the oil a lot easier if you mount the filter in the upright position to minimize drips and leaks.

Remote oil filter mounted on front bumper support

In my case, I also wanted to add an oil cooler to the engine, as it would be supercharged and I had anticipated some additional cooling system stress because of it. I used a high-performance stacked plate (not a cheesy tube and fin) oil cooler by Setrab of Sweden. The cooler I selected was a 10-plate design with -10 AN fittings on top. It is a very high quality unit for which I fabricated a simple aluminum bracket that located the cooler just behind the opening in the Ranger's front bumper for excellent airflow. To protect the oil cooler from road debris and rocks, I installed some stainless steel mesh in the bumper opening. It is important to mount the cooler such that the fittings are on the top of the cooler, rather than on the sides or bottom. This is to prevent air from getting trapped in the cooler and reducing its effectiveness and possibly starving the engine for oil. I used –10 AN 90 degree fittings on the cooler and ran braided hose to the filter adapter (which has two "in" and two "out" fittings). The oil in my Ranger runs out of the engine, to the filter, to the cooler, then back to the engine, in a big loop. I also installed a Ford Motorsport high-volume oil pump to handle this additional load. If your donor engine has more than 40,000 miles on it, replace the oil pump and driveshaft--it's cheap insurance and nearly impossible to do once the engine is in the truck.

Oil cooler mounted behind front bumper
(also note dual pusher fans for cooling)

You can get oil coolers with integral fans that serve the coolers alone, but since I anticipated that the cooler would not be necessary unless the vehicle was under load, I felt that the airflow generated by the truck's motion would be sufficient to cool the oil. It is important to properly size an oil cooler to your application, as too much cooler is as bad as too little, and if you frequently run your Ranger in the winter or in cold temperatures, I would urge you to consider an in-line thermostat for the cooler to regulate oil temperature. Ideally, I like to see my oil temperatures around 200 degrees, regardless of the situation, and the Setrab unit has no problem maintaining this, even under full boost with the A/C running in the desert.

Depending on the year of your donor motor, you may also need to change the oil pan. The oil pan found on most fuel injected (1986-1995) 5.0L engines is called the "dual sump" because of its front and rear reservoirs and two drain plugs. This pan is ideal for the Ranger swap because the two sumps are positioned in front of and behind the engine crossmember in the Ranger, and will not cause any clearance problems on the bottom. 5.8L and motors without the dual sump oil pan will require an oil pan change to the dual sump design. Remember to change the pickup tube and the dipstick tube when changing oil pans. New dual sump oil pans, pickup tubes and dipstick tubes for the 5.8L motors are available from Ford Motorsport (part no. M-6675-A58) and Kaufmann Products (no part no. available). 80's Crown Vic police cruisers with the 5.8L motor also used a dual sump oil pan, so you may be able to order one from your local Ford dealer as well.

COOLING:

Most factory Ranger radiators are inadequate for the cooling demands of even a mild V8, let alone one as easily modified as the 5.0L. Later Rangers equipped with the factory super-duty cooling system have large, efficient aluminum radiators that can be retained for use with the V8. According to the radiator experts at Be Cool, Inc., the Ranger's super-duty radiator is about the most efficient design available for that vehicle, and they reluctantly admit that they probably could not build a custom radiator with more cooling capacity to fit in that location. With this in mind, consider retaining the super-duty radiator (if your Ranger was originally equipped with this piece), or acquiring one for use with your V8. The only issue that the stock radiator may raise is clearance. Because the V8 is longer than the I-4 or V6 it replaces, it will eat up some of the space between the engine and the radiator in the engine bay. How much space depends on your engine's location, which is determined by your engine mounts. If you are using some of the off-the-shelf engine mounts mentioned earlier, you should have sufficient clearance at the front of the motor for a large electric fan, which will adequately cool the radiator. However, an engine-driven fan, even a flex fan, may not work because of clearance issues.

If you wish to use an engine-driven fan or would like some additional clearance at the front of the motor, the aftermarket has come to your rescue. Total Performance (part no. 83/RB 8005: about $275), James Duff Enterprises (part no. 3630), Advance Adapters (part no. 716683) and Kaufmann Products (part no. not available) offer high-capacity 4-core radiators specifically for V8 Rangers. The design of these radiators make them perfect for those needing more engine clearance in the front of the engine compartment. All of these radiators (they may all be the same radiator, I'm not sure) are designed to sit inside the radiator cradle instead of behind it, thereby adding as much as 2 inches of additional clearance, usually enough to allow the use of an engine-driven fan. All seem to be of brass and copper construction, which is efficient, but heavy (about 4 times as heavy as the aluminum OEM super-duty radiator). However, none of these radiators should have any problems cooling even a heavily modified V8 motor.

One final note on these aftermarket radiators: if your Ranger has A/C, these radiators require the relocation of the condenser to the front of the radiator core support because of the radiator's new location. Moving the radiator also means new A/C hoses, lines, and brackets, not to mention extensive modifications to the grille and support pieces. Many, many people have used these radiators with great success, and are a no-brainer for those of you with deep pockets and/or a truck without A/C. On FrankenRanger, we decided to use the factory super-duty radiator because we did not want to move the condenser, but our clearance between the engine and radiator is almost zero. Because of this, we were forced to use dual electric PUSHER fans in front of the condenser and radiator. Should this setup prove inadequate, we do have the Total Performance radiator sitting on the shelf, ready to go…

Speaking of fans, this is a critical part of the cooling system that most people overlook almost from the beginning. Proper airflow is at least as important as a large radiator, since without airflow, no radiator will adequately cool the motor. Most fans are measured in the amount of air they move, expressed as cubic feet per minute, or CFM. This is more common to electric fans than to engine driven fans, primarily because engine driven fans airflow ratings are dependent on how fast the engine is spinning. The airflow measurement should be one guide that will help you decide which fan is best for your application, though you should be careful to compare apples to apples. For instance, some fan manufacturers measure their fan's output at zero air pressure, which, of course, is not a real world situation, and tends to exaggerate the fan's capabilities. Most electrical fan manufacturers will provide data on their fan's performance at various pressure levels. The bottom line? Get the fan that flows the most air under all its advertised conditions and you can't go wrong.

Dual 12" pusher fans mounted in front of A/C condenser.
Also note -10 AN oil cooler lines and fittings.

On my projects, I am partial to electric fans, since they can be adjusted to activate at different temperatures, so they are only "on" when needed. Unlike an engine-driven fan, an electric fan has very little parasitic drag on the motor, and therefore your engine can put more power to the rear wheels. Electric fans also have the advantage of providing full airflow at low engine speeds, so when you are idling in traffic, your engine will not heat up as dramatically as with an engine-driven fan. Finally, electric fans can fit into spaces too narrow for engine-driven fans, or used for special applications such as oil and transmission coolers. Most major auto manufacturers now use electric fans almost exclusively in their new cars, so there's no need to be afraid of reliability or complexity issues.

Electric fans often come in kits that include mounting hardware, but you can also make your own fan mounts from aluminum sheet. Mounting an electric fan using nylon tie wraps or through-the-radiator plastic clips is specifically not recommended for durability and safety reasons. When starting up, an electric fan, especially a larger one, will generate a considerable amount of torque that can tear wimpy plastic mounting tabs. On FrankenRanger, we fabricated an aluminum shroud to hold two SPAL 11" pusher fans on the front of the radiator core support. The fans were bolted to the shroud and the shroud bolted to the core support using threaded inserts. The shroud was also painted satin black for an OEM look and low visibility behind the Ranger's grille.

If at all possible, you should use puller fans mounted behind the radiator to draw fresh air through the radiator (and A/C condenser) from the front of the vehicle. Pusher fans, while often rated at similar airflow levels, are not as efficient at cooling the radiator because of pressure losses across the radiator core. As an example of this, put a finger over your mouth and inhale and exhale around it. Notice how much cooler the air feels and how much quicker it flows when you inhale. Fans and your radiator work the same way.

By far the best electric fan I have ever seen is off of the late-model Lincoln Continental and Mark VIII. This fan moves serious amounts of air, and can be easily adapted to work in the Ranger engine bay. SPAL also makes a line of very high quality electric cooling fans that are available with complete mounting hardware and wiring components to make installation easy. On FrankenRanger, I used both a 180/195 degree on/off coolant temperature sensor AND a manual switch to control the operation of the fans. In this way, I can insure that the radiator and A/C condenser will always have sufficient airflow, even if the engine is not running.

Dash-mounted fan control switch with red LED "ON" indicator

With electric fans, I strongly recommend using relays to trigger the fan, rather than running the full 12V current through a switch, which can generate a lot of heat and possibly cause a fire hazard. Relays act as a kind of "remote" switch, allowing you to use low voltage to trigger the relay, which then passes the current required from the battery to the fan. In this way, you eliminate the possibility of fried wires in your dashboad or under your hood. Most quality electric fan manufacturers will offer some sort of relay and wiring harness to make the job simple, but you can easily duplicate this setup yourself using standard 40 amp relays from your local auto parts store. Also, use only one fan per relay—activating more than one fan with a single relay is a recipe for a spectacular meltdown.

Coolflex hose and rubber 90 degree elbow easily adapt 4.0L radiator to 5.0L engine.
Note aluminum bracket holding hose and relocated charcoal canister (lower right corner).

You will also need hoses to connect the radiator to the engine. If you use one of the aftermarket radiators, you should be able to use Early EFI Mustang molded radiator hoses without much difficulty. If you elect to keep the Ranger super-duty radiator, you will have to do some searching at your local auto parts store for a hose that closely approximates the bends that you will need. You may find it useful to make a template with a wire so that you can measure it against the hoses you find at the auto parts store. A third option, one that we used with both the upper and lower radiator hoses on FrankenRanger, is stainless steel flex hose, such as that made by CoolFlex, bent into the desired shape. The stainless hose effectively radiates heat, doesn't wear out or burst, and really looks trick. In some cases, it may be the only choice, depending on the complexity of your installation.

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