Taking the time to evaluate your oiling system and make improvements where necessary not only protects your engine by preventing problems but it can also be a source of even more performance gains. The cooling system of a vehicle is critical in removing the additional heat created as you increase engine output to improve vehicle performance. In this chapter I briefly take a look at where some opportunities may lie within these systems to protect against problems and also make some gains.
This Tech Tip is From the Full Book, FORD MUSTANG 1964 1/2 – 1973: HOW TO BUILD & MODIFY. For a comprehensive guide on this entire subject you can visit this link:
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The oil pan holds the oil and makes sure oil is available to the oil pump pickup under all conditions. Forces are placed on the oil and the oil pan’s design and baffling must ensure that the oil pickup remains submerged.
The pan design can be relatively simple because a common street car isn’t subjected to high-g loads. The pump pickup generally is not uncovered for very long (or at all) because these vehicles can’t accelerate very hard. As performance increases, however, as it does with a higher-horsepower Mustang, the oil pan needs enhanced baffling to compensate.
High-Performance Oil Pan
A high-performance oil pan has greater capacity and the incorporation of baffling to help keep the oil near the pickup under all conditions. The increased capacity surrounds the pickup with more oil so there is enough left around the pickup to feed the engine until the dynamics change and the rest of the oil returns.
For a drag racing application, the pan is deeper to further submerge the pickup and add baffling to the rear of the sump to help keep it filled under hard acceleration. Additional baffling is also usually put at the front edge of the sump to help retain the oil under hard braking.
Little attention needs to be paid to what happens to the oil while turning because, hopefully, that only occurs at slower speeds at either end of the strip. A drag race pan doesn’t usually make a very good street oil pan because the extra depth can be problematic in terms of ground clearance.
Road Racing Oil Pan
A better alternative for a street performance car/track-day car is an oil pan designed for road racing. Such pans are normally not much deeper than a stock pan yet they achieve their added capacity by having a sump that’s wider and in some cases a bit longer than stock. This gets you the added oil capacity without much, if any, loss in ground clearance.
A special oil pickup tube is required for use with this pan design, and it can be further optimized to be less restrictive than the stock pickup. You can use a metal standoff over the pickup screen to ensure a minimum amount of clearance between the pickup screen and the oil pan floor. Once you correctly relocate the oil pickup for the new pan design you can determine the placement of the baffling.
For a small-block road race pan, Milodon, for example, effectively uses a series of chambers and trap doors to allow the oil to flow only in certain directions under specific conditions. This tends to keep more oil around the pickup while also allowing quicker replacement of the oil when the vehicle direction changes. Baffles are strategically placed to control the oil in all directions. The combination of this baffling with the extra oil capacity is extremely effective in preventing the oil pickup from being uncovered and sucking in air.
The Accusump by Canton Racing Products provides a reliable supply of oil in high-performance applications, especially those with very rapid and extreme direction changes. This device stores a specific amount of oil under pressure while the engine is running. It is connected directly to the engine oiling system, preferably as close to the oil pump output as possible. Should there be a drop in oil pressure it causes the oil in the Accusump to immediately begin flowing back into the engine to provide pressurized oil until normal pressure returns. Once that occurs oil is pumped back into the Accusump so it is ready for the next drop in oil pressure.
By installing a driver-controlled valve between the Accusump and the engine the driver can close the valve before the engine is shut off, thus capturing the volume of pressurized oil in the Accusump. Before the engine is again started the valve can be opened to provide oil to the engine during startup. This can greatly increase engine life and reduce the potential for scuffing, etc., until the oil pressure rises to its normal level.
The Accusump is available with various capacities to be used in different ways. A smaller one, for example, can be used as a pre-oiler for turbochargers to greatly prolong the life of their bearings at start-up and in the event of a temporary drop in oil pressure.
The Accusump can be mounted virtually anywhere there is space for it. Other than a couple of mounting brackets and the need to run some relatively large braided line or hose to the engine there’s not much involved in installing and using one.
A pressure gauge and air valve mounted on the unit are used to adjust and monitor the internal pressure (directly proportional to the engine oil pressure).
For its price an Accusump is very cheap insurance against a big repair bill and/or bodily harm should an engine fail.
Dry Sump Oiling System
For the most extreme streetable track-day car the ultimate oiling system is a dry sump type. This system gets its name from the fact that external pumps are used to scavenge the oil from a very shallow oil pan so it can be directed to a large reservoir for de-aeration. A separate pressure pump stage supplies the minimally aerated and (optionally) cooled oil through a filtration system and then back to the engine under pressure.
The main advantage of a dry sump system is that the shallow oil pan allows the engine to be mounted much lower, thus lowering the center of gravity. This works well in a race vehicle with a tubular frame but it may not be feasible in a production vehicle unless significant changes are made to the front structure.
In cases where there are few limitations with regard to cost a dry sump system can be especially appealing not only for the better engine location but for the increased performance, which comes from the vastly better evacuation of oil from around the spinning crankshaft. This greatly reduces “windage” losses inside the engine and can free up a significant amount of power otherwise lost as parasitic drag. Dry sump systems aren’t cheap, but they are extremely effective.
Wet Sump Oiling System
A wet sump system is suitable for most mild- to high-performance street engines. You can gain significant performance by keeping the oil away from the rotating assembly that creates drag. To some extent a deeper oil pan accomplishes this but the real gains come from the installation of a windage tray and/or oil scraper.
These devices attach to the main cap fasteners and/or along the oil pan rail. Their purpose is twofold: They provide a barrier between the spinning crankshaft and rods, etc., and the oil (mist and/or liquid). They also try to remove as much oil as possible from those spinning components so it can be directed back to the oil pump pickup as soon as possible. Pretty significant gains in power (sometimes 20 hp or more) can be realized if this is done well. The use of a bearing-cap girdle can sometimes preclude the use of a windage tray and/or oil scrapers but if there’s any way to accommodate it, you should.
A high-volume oil pump is generally a good idea simply because it helps ensure the engine has enough oil at any given time. A high-volume pump is especially needed when larger bearing clearances are being used, though this is likely only in a competition engine. Street-driven vehicles need engines with relatively tight bearing clearances. Still, the extra volume can help with cooling the bearings as well as offering better protection overall.
A high-pressure oil pump is generally only needed when very high RPM are experienced and/or when you have things such as oil cooling jets for the pistons, which require higher pressure to work properly. Having more pressure than you need is just a waste of energy.
A high-volume standard-pressure pump is usually the best option for street-driven performance/track-day cars. If you use such a pump it is also a good idea to upgrade to a hardened pump driveshaft because the extra force needed to drive the high-output pump can cause premature wear or even failure of a standard shaft, especially under higher-RPM conditions.
A one-piece pan gasket is simply much more convenient and seals are much better than older, multi-piece cork gaskets. Make sure you get the type that have the hard inserts to prevent overtightening, which can damage the soft gasket and/or create leaks.
A flexible dipstick provides more mounting options, it looks better than a metal tube, and the positive seal keeps proper crankcase pressure with everything looking neat.
The importance of using an appropriate engine oil cannot be understated, nor can the need to change it as necessary. For highperformance applications a synthetic blend of the proper weight generally suffices. However, when you have a power adder and/or very high power levels it’s best to use a full synthetic. Companies such as Red Line and Royal Purple specialize in high-performance lubricants and generally offer a superior product.
Such oils are formulated for higher film strength to compensate for higher loads and RPM. They are more resistant to foaming or degradation from high heat (especially important when turbochargers are used). They also provide superior corrosion and sludge resistance (thus providing the potential for longer change intervals).
Other specialty oils include those with unique formulations. Some include extra amounts of ingredients such as the zinc and phosphorus required for older vehicles with stock, non-hardened valveseats.
As you increase engine output to improve vehicle performance you also create, usually in direct proportion, additional heat that the cooling system must remove from the engine. In most cases, especially the early 19641 ⁄2–1966 cars with smaller radiators, you soon exceed the capacity of the stock cooling system and experience overheating problems. Fortunately, there’s no shortage of steps that can be taken to improve your car’s cooling performance.
A lower-temperature thermostat is the easiest and least costly move to make. This reduces the temperature of the engine coolant, which can provide a little extra performance by reducing the temperature of the intake charge so it is denser. Dropping one step in temperature (from 205 to 185 degrees or from 185 to 160 degrees) is usually enough to make a noticeable difference. Dropping more than one step is usually not advisable because it may require adjustment of the fuel mixture (carburetor jetting, choke, etc.). It also significantly degrades the performance of the heater and/or defroster, which can be an issue in cold and humid climates.
For a carbureted engine you can often use a thermostat rated as low as 160 degrees F. For EFI-equipped engines, however, there can be problems with the function of the ECU when using thermostats rated below 180 degrees F or so.
Replacing the thermostat is a standard repair/maintenance operation, requiring only the new thermostat, a new gasket, and perhaps some RTV or other sealant to provide extra insurance against leaks.
Be sure to verify that the radiator cap has the correct pressure rating for your application and that it seals properly with the radiator neck. You might also want to increase the pressure rating slightly for highperformance situations because this can help reduce the formation of bubbles in the coolant when it encounters the hotter spots inside the engine (such as near the exhaust valves).
Making more power likely raises the temperature at these areas, thus increasing the potential formation of bubbles. A higher-pressure radiator cap somewhat offsets this to help maintain maximum cooling by promoting the presence of more liquid coolant in these areas, which has a greater ability to remove the extra heat generated than does the presence of bubbles. This can be further ensured by using a coolant additive such as Red Line’s Water Wetter or Royal Purple’s Purple Ice to alter the characteristics of the coolant so that it is better able to remove and transfer heat from the engine.
These additives can lower coolant temperatures by 20 degrees F or more. They can allow the use of water only versus a water-coolant mix because they also include corrosion inhibitors and other additives needed in a street-driven vehicle. Using 100-percent water with one of these additives has a higher heat transfer capability than a watercoolant mix and thus can provide the greatest cooling capacity as long as potential freezing is not a concern.
Whatever coolant you decide to use it’s a good idea to install a filter to clean and monitor it.
Factory fans were almost always fixed-blade steel fans, which worked reasonably well, especially when they had many blades. These fans had two issues, however: They were dependent on engine speed and they created a lot of drag on the engine.
The first issue becomes a problem when you’re stuck in traffic on a hot day, possibly with the A/C on. The low engine RPM means low fan RPM, which means there is not much airflow right when you need it most. This is because of the high ambient temperature plus the added heat load the A/C system puts on the engine and the cooling system.
The drag of the A/C compressor means more fuel is burned and thus more heat is created by the engine to be removed. The A/C condenser is almost always located in front of the radiator so the heat it throws off goes right into the radiator. This reduces its effectiveness due to it getting some already heated air along with the cooler ambient air.
The only way to resolve these issues (other than relocating the condenser away from the radiator, which is rarely feasible) is to flow more air through the condenser and the radiator. Because the stock fan is tied to engine speed this is not possible unless you want to be constantly revving the engine, which is only marginally helpful.
A good solution is to have a better fan and/or more fans that are not as dependent on engine speed for airflow. The simplest approach is to change the stock mechanical fan for one that moves more air at a given engine speed. Unfortunately, a flex fan does not do this; it actually flows less as the blades flatten out at higher RPM and should therefore never be considered for a street-driven vehicle.
You can use an OEM fan with more blades, say from a larger engine and/or one that came equipped with factory A/C. This flows more air at any given speed but is still directly dependent on engine speed to create flow. This option should only be considered if you have a very minimal cooling issue and you want to spend as little as possible.
A better option is to use a clutchtype fan from a later-model vehicle such as a 5.0L engine from a FoxBody (1979–1993) Mustang. The fan is oversized in terms of airflow potential so there’s plenty of reserve capacity to keep the engine cool. The installation of a later-model thermostatic clutch fan can often prove to be beneficial in terms of freeing up some power and also providing better cooling, even if a fan shroud doesn’t fit.
The thermostatic nature of such fans allows them to basically freewheel or slip somewhat when maximum cooling isn’t needed, thus taking less energy from the engine to drive them. However, when more cooling is needed the amount of slippage is reduced to where the fan is essentially connected almost solidly to the engine, thus providing much greater airflow.
A greater number of fan blades along with their greater surface area and steeper pitch provide much greater maximum flow yet deliver it only when it is needed.
A fixed-fan’s flow rises with RPM even if it’s not needed. They are a bit heavy, they may require some adaptation to fit on older cars, and they usually require a custom fan shroud because they are much larger than stock-type fans. However, once they’ve been installed the only maintenance is to clean any dirt or dust off of the thermostatic coil so it can function properly. These fans can be relatively inexpensive if bought used.
A slightly more costly and complicated solution to cooling challenges is to replace your mechanical fan with an electric fan. This has several advantages. First of all, its operation is completely independent of engine speed. It comes on via a manual switch or, more commonly, a sensor mounted on the radiator turns it on when a certain preset temperature is reached. Many fans also provide a means to switch the fan(s) on whenever a certain event occurs, such as the A/C compressor turns on or a nitrous system is activated. It can be completely automatic.
Electric fans come in many shapes, sizes, and airflow ratings. Most have built-in shrouds. The more powerful fans usually require that they be connected directly to the battery (often via a relay) because they draw a lot of current. Most can be attached directly to the radiator core after the mechanical fan has been removed.
Fans mounted between the radiator and the engine that draw air through the radiator are known as “puller” fans. Fans mounted in front of the radiator (and also the condenser on A/C-equipped cars) force the air through the radiator and are thus known as “pushers.”
Pushers are generally less efficient than pullers but they can be effective at increasing the performance of a puller when the radiator core is especially thick. They can also improve the performance of the A/C system by forcing more air through the condenser.
The cooling system upgrades discussed thus far are applicable to any of the vehicle types being discussed in this book though they are aimed mainly at daily-driver and streetperformance vehicles. When power levels rise significantly beyond stock levels, A/C is retrofitted, indoor extra coolers are added, etc., virtually all of these upgrades and even more are needed to remove the additional heat. The OEM radiator is probably no longer up to the challenge.
Fortunately, there is no shortage of high-capacity radiator upgrades for early Mustangs. Most are direct fit and can easily replace the OEM radiator while providing more cooling power. Special configurations are available for popular engine swaps such as the installation of a later 5.0L engine, which requires a change in the location of the hose fitting on the radiator. Its use of a serpentinebelt drive causes the water pump to rotate in reverse, thus requiring that the hose outlet be located on the opposite side of the car. Having a radiator that already accommodates this difference is convenient and less expensive than adapting it yourself.
In most cases an aluminum-core radiator is preferable to a copper/ brass type due to its reduced weight and reduced cost. The aluminum radiator doesn’t look stock so if that’s a consideration you may want to stick with a thicker (three- or fourrow versus the usual stock two-row) copper/brass radiator. An aluminum radiator is a bit thicker and requires a higher-flowing fan (and/or multiple fans) but the reduced weight and lower cost are worth it. They may also increase the radiator thickness and its frontal area.
Aluminum radiators have more-efficient tube and fin designs so that those with 2-inch-wider tubes, more frontal area, and/or better fin design (internal and external) are usually able to dissipate more heat than a heavier three- or fourrow copper/brass radiator using older technology. They also can still have internal transmission oil coolers and other features that allow them to be direct bolt-ins.
When buying an aluminum radiator avoid any that use epoxied joints because they can crack and leak. They also reduce the heat transfer potential of the core. Brazed joints are superior in heat transfer, strength, and durability. You must also ensure the filler neck clears the hood.
For the highest power levels such as are seen in a highly modified street performance car and a streetable track-day car even more extreme measures must be taken to ensure proper cooling. This is especially true for the latter vehicle type because it will likely be operated at very high speeds and outputs for an extended period of time.
At the Silver State Classic open road race near Ely, Nevada, for example, it is quite common for many vehicles in this event to run at full throttle for almost the entire 90-mile course. This can be as little as 1/2 hour for the fastest unlimited class cars to about an hour for the slowest cars. Even at the slower speeds many stock vehicles have trouble with overheating. The faster you run, the more important it is to upgrade the cooling system if you want to have any hope of finishing without overheating. This requires not only upgraded individual components but also considerable effort to match the components to achieve optimum performance.
One way to ensure this is to use a cooling “module” instead of acquiring your parts independently. An excellent example is the Be Cool direct-fit Classic radiator/fan module. It’s rated for 700 hp (they also have 1,000-hp modules with bigger fans as well as 400- and 300-hp versions). It includes everything you need: from radiator, fan module, mounting brackets, etc., to a matching hardware kit, billet radiator cap, and overflow tank. You also get all of the necessary wiring and other items you need for a “hassle-free installation” (their claim).
Be Cool guarantees this module drops your coolant temperature by at least 20 degrees F. They even double the warranty period to two years if you use only their Be Coolant Super Duty Antifreeze. It is a special biodegradable propylene glycol formulation that lasts for 7 years/300,000 miles and protects aluminum and other cooling system components down to -26 degrees F. It has a boiling point of 267 degrees F at 15 psi and it’s made in America.
The final thing to consider relative to engine cooling is the water pump.
Daily Driver Applications
For a daily driver there’s usually no need to use anything more than a good-quality direct-replacement OEM-type pump if yours needs to be replaced. Just make sure it is made by a reputable company and has improvements in the impeller, bearing, and seal designs. Stay away from plastic and stamped steel impellers if possible. A cast impeller is almost always more efficient and more durable.
As to high-performance street and streetable track-day vehicles, pump performance needs to increase. First of all, there must be sufficient coolant flow. This requires the impeller and pump housing to be designed for optimal flow. They’re also manufactured to closer tolerances to achieve it and keep it over time.
Next, the higher-RPM use of these applications places more stress on the components so the highestquality bearings and seals are required for durability.
Finally, achieving the best cooling and engine performance requires the coolant flow to be sufficient in terms of volume and pressure as well as balanced from bank to bank. OEM replacement water pumps place little, if any, emphasis on this but companies such as Edelbrock make it a priority.
Victor Series high-performance water pumps incorporate all of those design properties plus a precision-cast powdered-metal impeller with oversized vanes for maximum flow and pressure. The design also ensures no more than a 1-percent flow difference from bank to bank.
For competition-oriented applications such as the streetable trackday car an even further upgrade is possible in the form of Edelbrock’s Victor Pro Series competition water pumps. These add features such as a revised impeller entry for even greater flow, still morerobust components (thicker shaft and backing plate, billet hub, heavy-duty ball/roller bearing, etc.), and multiple hose connection options (standard hose, AN or NPT fittings, etc.). These pumps can also be used in highperformance street applications although the extra flow, strength, and expense are rarely justified in all but the most powerful and extreme instances.
Drag Race Applications
Electric water pumps make perfect sense in a drag race scenario where they can eliminate parasitic drag during the brief run down the strip yet they can run with the engine off to cool the car during the trip down the return road and in the pits. They also eliminate the need for a drive belt/pulley, which simplifies the front of the engine, saves some weight, and frees up space for extra belts, etc., to drive superchargers and so forth.
Although some electric water pumps have been used on production vehicles they are built for longterm durability. They are usually also computer controlled to vary flow based on engine coolant temperature and other factors. The electric water pumps offered by the aftermarket and for racing purposes are generally not as sophisticated and, if they were, they would be quite pricey compared to a mechanical pump. They also are not really designed for long-term durability nor are they well suited to frequent street use, especially in areas with extreme weather.
Written by Frank Bohanan and Posted with Permission of CarTechBooks