Few things are as exciting as firing a fresh engine. With those first hot pulses of combustion, a new engine begins to warm up and come into its own. Before you can safely fire the engine, however, you need to make sure the engine and all of its support systems are ready for action. In other words, you should inspect and determine that the cooling, oiling, exhaust, electronic engine control (EEC), and ignition systems are performing up to spec. In addition, the driveline, brakes, tires, wheels, and suspension must be able to support the power from the engine. It all has to work together cohesively to be enjoyable and safe.
This Tech Tip is From the Full Book, 4.6L & 5.4L FORD ENGINES: HOW TO REBUILD. For a comprehensive guide on this entire subject you can visit this link:
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Building a powerful engine and installing it in a vehicle with really bad brakes or a mushy suspension is foolish. Installing a clogged radiator with rotted hoses in front of a new engine is courting trouble. Be sure the components of your vehicle infrastructure are reliable. You can use dyno testing to tune for power, as well as reliability.
It goes without saying that your new engine needs a good support system to live a long time. Install a brand-new radiator and a cooling system filter in the upper radiator hose to catch stray iron and aluminum particles during break-in. The coolant filter captures rust and aluminum particles that dislodge and become trapped in the new radiator tubes. During the first several thousand miles, check the coolant filter and make sure it is clear. A clogged coolant filter creates the same kind of overheating issues as does a clogged radiator.
Resist the temptation to save a few bucks by installing an old thermostat in a new engine, even though automotive thermostat function has not changed much in nearly 100 years. The thermostat is a simple spring-loaded popette valve with a sealed actuator filled with wax. As the wax becomes hot and expands, it grows against spring pressure, opening the valve and allowing coolant to pass. A thermostat’s operating temperature is determined by spring pressure. The more spring pressure you have, the higher the operating temperature.
For example, a 195-degree thermostat has more spring pressure than a 160- or 180-degree thermostat. Thermostats fail when wax leaks out of the actuator and there’s no force against spring pressure. A thermostat that doesn’t open may be “stuck,” or the wax may have leaked out and the actuator failed. This is why a failed thermostat causes the engine to overheat.
Here’s something else you need to know about thermostats: Never run your engine without one. Erroneous logic says that an engine without a thermostat runs cooler, but exactly the opposite is true. When you remove the thermostat, coolant never has a chance to stay in the radiator long enough to transfer heat to the atmosphere. As coolant rushes through the water jacket and radiator, it
doesn’t dissipate the heat and the engine simply becomes hotter and hotter, leading to overheating. If you are stuck in traffic without a thermostat, your engine overheats and boils over. The same is true for cruising down the highway.
Think of your engine’s thermostat as a cooling system traffic cop. It regulates the flow of coolant in and out of your engine. It holds coolant in the engine until it reaches a given temperature. Wax expands inside the thermostat’s actuator, forcing the thermostat’s valve open against spring pressure. Hot coolant flows into the radiator for cooling. Coolant flows from the radiator into the engine’s water jackets, where heat is transferred from hot engine parts to the coolant. While the thermostat is closed, coolant in the radiator gives up its heat to the airflow. Heat is also transferred via the vehicle’s heater core, which is also a small radiator.
The 4.6L Modular V-8 calls for a 195-degree thermostat, which is important to proper EEC function. Remember, heat retention is just as important as heat dissipation. Computer-controlled Modular engines have a minimum temperature and must function between 192 and 195 degrees F. This is the coolant’s temperature when the ECM operates properly. The correct engine temperature is important to proper fuel atomization and burning. It is also important to proper oil flow throughout the engine.
New cooling system hoses and a new water pump should accompany a new radiator. Even though a water pump may look fine and be free of leaks, that doesn’t mean it was pumping effectively when the old engine was removed. Water pump impellers become covered with rust and scale, which reduces pumping efficiency. When you are shopping for a new water pump, buy a high-flow unit for the best cooling efficiency.
Cooling fans are designed to do their job primarily when a vehicle is sitting still. They don’t serve much of a purpose when the vehicle is in motion. When you are shopping for cooling fans, you have a wide variety to choose from.
The most efficient engine-driven cooling fan is the thermostatic clutch fan, such as in Grandpa’s big, stodgy sedan. Thermostatic clutch fans are the most efficient because they work only when they’re needed. Some clutch fans aren’t thermostatic. These fans slip normally, operating at a lower speed than the water pump. This isn’t good for highperformance engines, which run hot by nature.
Originating in the late 1960s, flexfans move a lot of air at low speeds. When the engine revs, the blades flatten, which reduces air resistance and saves power, but these fans tend to be noisy. Aftermarket flex-fans such as those from Flex-A-Lite are quiet and effective coolers.
Electric fans must be chosen with common sense. Not all of them are designed to cool as effectively as their manufacturers would have you believe. Choose a fan based on cubic feet of air per minute (CFM). Choose an electric fan that’s thermostatically controlled, so it comes on when it’s needed, and turns off when it isn’t.
Ideally, an electric fan covers 100 percent of the radiator’s surface area, but the objective is to keep air flowing across the tubes and fins at all times to draw the heat out of the coolant inside. Marvin McAfee of MCE Engines says you want a minimum of 2,500 to 3,000 cfm from a radiator-cooling fan. Otherwise, your engine will likely experience overheating issues.
When you fill the cooling system for the first time, opt for the appropriate 50/50 mix of ethylene glycol and water. Use Water Wetter coolant additive to improve coolant retention and eliminate corrosion. Running straight tap water without antifreeze isn’t a good idea unless you’re using a good corrosion inhibitor. Tap water has all kinds of minerals that can clog a cooling system.
Budget permitting, the best coolant is Evans’ non-aqueous coolant, which works well all by itself. It retails for about $60 per gallon. It is a very effective coolant because it transfers heat better than ethylene glycol. And because it doesn’t contain water, corrosion is never an issue.
You need to be concerned about leaks when you assemble the engine. Double-check all hoses and connections before the coolant goes in. Use a good cooling system rust inhibitor while you’re pouring in the coolant, and realize that the coolant expands with temperature. Don’t fill the radiator to the top; fill it just to the top of the tubes. As the engine warms, the coolant expands and takes up the top tank, so have a pan ready to catch any overflow.
Never use radiator stop-leak, for any reason, no matter what anyone tells you. There are no magic pills. If you have a leaky radiator, repair or replace it. Do not have a radiator shop cut out precious cooling tubes that contribute to engine cooling. Stop-leak additives may stop the leak, but they also hinder the radiator’s ability to cool the engine because they plug marginal passages in both the radiator and the engine.
You also need to consider the condition of the heater core. You should replace the heater core if your Ford has never had a new one and it has more than 100,000 miles on the clock. I recommend a new heater core because modern ones are not of the quality they used to be. For example, 1979–2004 Mustang GTs and Cobras tend to blow heater cores. Ford solved this problem to some degree when it started installing heater hose restrictors, which reduced volume and pressure at high revs.
Before you fire a new engine, consider a few things related to the oiling system. Although many people fail to do this, you should prime the oiling system. This not only confirms oil pressure and flow, it pre-lubes bearings and other pressure-lubricated parts for initial start-up.
Modular engines have a crankdriven oil pump, so you must turn over the engine without spark plugs installed and oil in the pan and filter. Ideally, the cam covers have been removed so you can observe oil flow during a spin test. Another option is to pump engine oil into the oil galleys from the oil pressure sender location. A hand-propelled hydraulic pump, hose, and the right fittings get the job done.
Install a New Radiator
Always install a new radiator or re-core your old one for maximum cooling effectiveness. A new engine needs efficient and effective cooling during break-in. It would be an absolute shame to ruin a good rebuilt engine because the radiator didn’t perform properly and overheated the engine. Hence, never underestimate your radiator’s ability to lose cooling capacity with mileage and corrosion, even when you perform regular cooling system maintenance.
Use a High-Flow Water Pump
Did you replace the water pump with a high-volume piece? Overcapacity beats undercapacity any day. Blueprint your water pump by smoothing rough edges and passages to reduce fluid turbulence. Always use a new belt. The 1999–up high-flow Cobra water pump works best because it is designed not to cavitate at high RPM.
Once the engine fires, let it run at 2,500 rpm for 30 minutes for good oil splash and pressure lubrication. In addition, running a Modular engine at 2,500 rpm allows bearings and rings a good shot at seating. Keep the radiator cap in place, but under detent to allow air to escape without spraying you with hot coolant.
As mentioned earlier, fill the radiator only to 1 inch below the top, but no farther until the engine is hot and the coolant fully expands. It is also important to remember coolant has a higher boiling point under pressure. This means it has a lower boiling point at ambient atmospheric pressure. Keep the radiator cap secured once all the air has escaped from the water jackets. If you forget to burp all of the air out of the water jackets, a hot pocket forms, causing localized overheating and a boilover.
Once the engine has had a chance to become hot, it’s a good idea to examine coolant for discoloring, check the oil (which should be dark or black to some degree from assembly lube), and check for leaks. The rear main seal area should be free of leakage. Closely inspect freeze plugs, intake manifold gaskets, valve cover gaskets, and the front timing cover for leaks.
During the start-up and break-in period, you should run Castrol 5W-20 or 5W-30 conventional engine oil. When you have 500 to 1,000 miles on the engine, change to Mobil 1 5W-20 or 5W- 30 synthetic engine oil with a Wix or Motorcraft oil filter. Always use a highquality Wix or Motorcraft oil filter.
After you have 1,000 miles on the engine, perform another inspection: Pull the dipstick and examine the oil. It should be free of debris and relatively clear. If it looks milky, you have coolant in the oil. The source of the coolant leak must be determined and corrected immediately. If oil consistency is like mud, the engine must be torn down and inspected. Too much coolant in the oil damages bearings and rings, turning a new engine into junk in short order. When you remember how important that layer of oil between moving parts is to engine survival, having pure oil in the pan becomes paramount.
Walking through an auto parts store shopping for engine oil can be confusing because so many brands, types, and viscosities are available. We’ve become accustomed to high-viscosity oils such as 10W-30, 10W-40, and 20W-50, so it’s hard to adjust to low-viscosity oils such as 0W-20, 5W-20, and 5W-30. Why are such low-viscosity oils used for newer high-tech engines? The answer is simple: tighter tolerances and higher operating temperatures.
Use the Best Oil Filter
You want maximum filtration, which means that you must never underestimate the importance of a good oil filter and a filter magnet. I suggest you opt for the highest filtration available from a major manufacturer such as Fram. Ideally, you will use a Wix, K&N, or Motorcraft filter, which are made to very high standards. Look for key elements such as filtration type, antidrainback valving, and bypass capability. The anti-drainback valve, visible through the holes, should be urethane for excellent sealing. Filtration material is normally a combination of paper and synthetics.
Ensure all wiring, hoses, and belts have been properly installed. Be prepared to shut down the engine if it loses oil pressure or coolant, or experiences some other problem. Once you’ve fired up the engine, allow it to run for at least 30 minutes at 2,500 rpm for proper piston ring and bearing seating. Idle speed alone doesn’t do it. Closely monitor the oil pressure, charging system, and of course, cooling system. If a gauge indicates a vital engine function is not in the normal operating range, shut down the engine.
To reduce emissions and improve efficiency, automakers have had to tighten tolerances. Tight tolerances need thinner lubrication. High-viscosity engine oils, such as 20W-50, work quite well in older engines, which are well worn and sloppy inside. High-viscosity engine oil takes up those loose tolerances and quiets things down.
Regardless of whether you need high- or low-viscosity engine oil, you need oil that flows. You’ve got to keep oil moving to maintain heat transfer and to keep the pump fed.
Ford doesn’t want your engine to fail any more than you do. So when choosing oil, be sure to use Ford’s recommendation: 5W-20 and even 0W-20 in some cases such as the newer three-valve and 32-valve engines. A few years ago, Ford recommended 5W-30, but that has since changed to even lower viscosities.
Be sure to look at the API service logo on the container of engine oil. In reference to viscosity, the logo tells you how the oil performs when cold or hot. The higher the viscosity number, the denser (thicker) the oil.
During break-in, you should use non-detergent oil. Once the rings have seated and your engine is broken in, use a detergent oil, which keeps dirt particles in suspension. Detergents are designed to trap impurities in the oil.
Sulfur was once used in engine oil to reduce friction in high-wear locations in the engine. Today, oil companies use molybdenum, which tends to turn the oil black with time and use. Black oil isn’t always a bad thing.
There’s no magic in the latest wave of “high-mileage” engine oils, by the way. These oils have seal conditioners that reduce or eliminate leaks. They don’t improve ring seating or quiet noisy pistons and bearings. For the most part, they don’t live up to the hype. If you have a high-mileage engine that leaks, you have a leaky gasket or bad seal that isn’t going to stop leaking. If your engine is blowing blue smoke at the tailpipe, it continues blowing blue smoke at the tailpipe because the rings are excessively worn and the valve seals are shot.
Engine Oil Filters
Although most engine oil filters look the same externally, they have large differences on the inside. Buy cheap and you get cheap. Unfortunately, you could also pay a lot for an oil filter and get less than you paid for.
Here’s what you want in a good oil filter: plenty of filter material, high-burst pressure, and good drain-back qualities. The Society of Automotive Engineers (SAE) conducts specific tests to determine engine oil filter quality and function. These tests are known as J806 and J1858 (see the website sae.org for more information). These tests look for the following:
- Drain-back and anti-drain-back issues
- Point where the filter becomes so blocked that the bypass unseats and the oil becomes unfiltered
- True filtering capacity
- Burst pressure
The SAE tests ensure that engine oil filters meet the manufacturer’s specifications. Although all engine oil filters must pass the J806 test, the J1858 test is tougher and reveals more. The J806 test is little more than running the filter and seeing how much it traps, plus bypass and drain-back qualities. The J1858 test gets into the nitty-gritty of what a filter actually traps and for how long.
The oil filter drain-back valve is a simple check valve or flapper valve made of rubber or urethane. It allows the flow of oil in one direction, but not the other. Some drain-back valves are metal-onmetal affairs that don’t always keep oil where it belongs. They leak down, in other words. According to Russ W. Knize, who conducted an extensive independent study of dozens of oil filters, drainback valves don’t always function as designed.
Oil filter choice tends to be a shell game conducted by just a handful of manufacturers. For example, a Motorcraft oil filter is Motorcraft in name only because this same filter is manufactured for many other brands. However, this isn’t necessarily a bad thing because the Motorcraft FL1A performed quite well in the Knize test comparison. It possessed the qualities you want in a good oil filter.
For the study Knize cut each filter open and shared his findings. He looked at all the same things the SAE looks for: amount of filter material, density of filtering material, drain-back issues, and more. Knize recommends choosing an oil filter based on filtering material and the thoughtful combination of good drain-back and bypass qualities.
His first order of business was assessing filtering material. He looked at how much filtering material there was to capture dirt particles. “Cellulose media [basically paper], can trap fewer particles and can flow less oil per square inch because there are fewer passages through it,” Knize stated. “Some filters have a combination of cellulose and synthetics, which does a better job of filtration.”
He added, “More pleats in the elements does not necessarily mean more surface area. In fact, too many pleats can end up restricting flow because there’s not enough area in between to allow oil to flow.” Aside from filtering material and good drain-back and bypass qualities, you want a filter with high burst pressure. You don’t find that in a cheap oil filter.
Check Charging System
You need to determine the charging system health before you fire up. Alternators need love too. Any qualified auto electric shop should be able to rebuild your alternator for less than the price of a new one. Brushes, bearings, and voltage regulator should be replaced. This is a Nippondenso 3G; your Modular engine may have the 4G, which is smaller and more powerful.
An oil filter magnet catches stray ferrous metal particles that can do engine damage, so I suggest using an oil filter magnet for the life of your engine. Several brands of filter magnets are available: Magna-Guard (magna-guard.com), Magneclean (amazon.com), MagnaFilter (bossproducts.com), Filter Plus (filterplus.com), Filter Mag (filtermag.com), and others.
Oil filter magnets are not a cure-all for oil system issues. However, the more ferrous metals you can keep out of circulation, the better. Filter magnet companies that promise improved fuel economy or significantly longer engine life are not telling you the truth. Certainly filter magnets can’t help but improve engine life, but not significantly. Much depends on how often you change your oil and what kind of oil you use.
Filter magnets do not improve fuel economy and do not keep non-magnetic particles from doing engine damage. For example, a filter magnet does not trap dirt or aluminum particles.
You can improve performance by installing the correct exhaust system on your Ford, Mercury, or Lincoln. Two basic types of exhaust upgrades are available: engine-back and cat-back. Engine-back systems include the catalytic converter and associated exhaust plumbing, and a cat-back system is from the catalytic converter back. Before you toss out your catalytic converter, remember that they not only clean up emissions, they also reduce noise levels significantly.
For a daily commuter, you want mufflers that deliver a soft, throaty tone at the tailpipe. If you’re building a 4.6L engine for a Mustang, factory mufflers tend to be the best choice. For example, the 2001 Bullitt Mustang GT muffler gives you a throaty exhaust note without being obnoxious.
Install New PCV Valve
The positive crankcase ventilation valve (PCV) does more than just ventilate the crankcase. If you shake a PCV valve, you will notice it rattles (or it should). That’s because the PCV valve is a check valve, allowing the flow of gases in one direction, but not the other. It is also a restrictor valve, allowing just so much vacuum leakage where crankcase fumes and pressure vent to the induction system for reburning. The PCV valve is a check valve because you don’t want an induction backfire to ignite crankcase fumes, causing an ugly explosion. PCV valves never go bad; they just get gummed up and stick. To replace one, disconnect the vacuum hose to the valve, lift the PCV valve from the valve cover, press the new PCV valve into place, and reinstall the hose.
If you’re going aftermarket, you want a low-restriction muffler that breathes, but you must be aware of sound levels. If you want an aggressivesounding exhaust, one of my favorites is the venerable Flowmaster three-chamber Delta Flow, which offers excellent scavenging and that legendary Flowmaster sound without being too loud in the cabin. One of the best mufflers for good all-around performance and sound is the DynoMax, which offers excellent scavenging without excessive noise levels.
Most enthusiasts want to know whether an X-pipe or H-pipe performs better. It has been proven through dyno testing that X-pipes produce more power. Sean Hyland says the H-pipe delivers better low-end torque, but nothing beats the X-pipe for producing high-RPM horsepower. Likely the best X-pipe comes from the granddaddy of X-pipes himself, Boyd “Dr. Gas” Butler.
H- and X-pipes without catalytic converters are known as “off-road” components because all street-driven vehicles must have catalytic converters. This is a federal law. When you’re shopping for catalytic converters, shop wisely for lowrestriction, all-metal models that improve exhaust scavenging.
Stock exhaust manifolds give everything they were designed to give. They’re high-tech, just like the engine. Although these manifolds are cast iron, they breathe better than anything that was available 40 years ago. But, if you’re like most of us, you want good-looking tubular exhaust headers.
The nice thing about shorty headers is that they bolt right on without modification. Aftermarket shorty headers are better than factory manifolds because they have improved flow from the larger tubes. If you want to keep underhood heat down, make sure you choose a set that’s ceramic coated.
Long-tube headers don’t make much sense for basically stock applications driven every day. For one thing, it’s hard to operate catalytic converters when you have long-tube headers. You want to remain legal, don’t you?
Electronic Engine Control
Ford has offered EEC-IV and EEC-V as the two basic operating systems for 4.6L and 5.4L engines. “EEC” stands for electronic engine control; “IV” or “V” stands for fourth or fifth generation, respectively. EEC operates with fluid precision, responding to your commands, and the engine’s commands, in nanoseconds.
Ford’s venerable EEC-IV has been in operation since the early 1980s. In the beginning, EEC-IV ECMs had a 60-pin connector. Later versions had a 104-pin connector, which is what you can expect to see on a 1991–1995 Modular engine.
The diference between the EEC-IV system and the EEC-V system, used from 1996–on, is diagnostics. The EEC-V features OBDII (on-board diagnostics, second generation) mandated by the federal government for tougher emissions standards and a no-tamper design.
If you install aftermarket headers, the oxygen sensors must be properly positioned. If you move the upstream oxygen sensors (before the catalytic converter) too far from the exhaust port, you will likely get a check engine light and struggle with performance issues. If you want to improve power without adversely affecting performance, consider the installation of an aftermarket performance chip. Just make sure you buy from a reputable chip burner who understands your needs.
Replace Cooling System Hoses
It’s a good idea to replace all cooling system hoses and the thermostat. Start fresh with new parts that will go the distance and use the factory clamps. Don’t let a 10-year-old hose burst and overheat your freshly rebuilt engine.
All performance modifications need to be compatible, so choose parts that work well together. The MAF (mass airflow sensor) needs to be calibrated to the correct injector size. Ford spends millions of dollars in research to determine what components work best together to meet both emissions and drivability standards. You need to be very diligent when selecting the parts for a performance package.
SOHC engines use 19-lb/hr injectors. The Lincoln Mark VIII has 24-lb/hr injectors. Supercharged 2003–2004 Cobras have 39-lb/hr injectors. The F150 Lightning has 42-lb/hr injectors. This should give you some idea of what size injector you need if you’re making more power than stock. Remember that stepping up to a 24-lb/hr injector on a base 4.6L SOHC engine does not give you more power, and if your ECM is not retuned for the new injectors, your performance and drivability are worse.
Most fuel injectors for the 4.6L and 5.4L engines have a single-spray pattern. However, other injectors, such as the 39-lb/hr injector for the DOHC engine, have dual-spray patterns to both reduce emissions and improve fuel economy.
When selecting an injector for a specific application, pick a fuel pump capable of properly supplying the injectors. Remember, too, that 1991–1998 fuel systems are return systems, which means undelivered fuel returns to the fuel tank via a return line and fuel pressure regulator. From 1999–up, Ford uses a nonreturn system.
Since its introduction in 1991, the 4.6L SOHC has had a distributorless, dual coil-pack ignition system. This is known as a waste-spark system because both coils fire at the same time, even though only one cylinder is on the power stroke. When cylinder number-1 fires on the power stroke, cylinder number-6, on the exhaust stroke, fires as well.
EEC-IV and EEC-V feature four-channel ignition controls, which work with the waste-spark ignition. In 1999, all Modular engines became coil-on-plug ignition systems, doing away with twin coil packs and adopting an eight-channel EEC, yet the ECMs are still EEC-V. If your engine has a waste-spark system, it might be a good idea to check the little condenser attached to each coil; they cause misfires then fail.
Spark plug wires are another potential weak spot. Because you’re running tremendous voltages through these wires, they should be replaced any time you do a rebuild. The lifespan for ignition wires is three to four years or 50,000 miles. As insulation breaks down, you may have crossfire and short-to-ground problems. Because the number-5 and the number-6 cylinders fire consecutively, you have a higher risk of crossfire between these bores. Watch spark plug wire routing carefully and use wire separators. A good aftermarket ignition wire set prevents crossfire thanks to heavier insulation. But there are still no guarantees.
Replace Idle Air Solenoid
The idle air solenoid (far left) controls idle speed with a controlled vacuum leak. The big black plastic thing (left) is the idle air solenoid silencer, which suppresses vacuum noise. And yes, you should use one.
Replace All Sensors
I cannot stress enough the importance of proper engine electronic function. By this time, you should have replaced all sensors to achieve satisfactory operation.
Retain All Smog Control Devices
Smog devices still suffer from a stigma of the 1970s. However, for your Modular engine to run well, they all must work. The EGR valve relies on manifold vacuum to function properly and cannot be gummed up or stuck. When in doubt, toss it out and install a new one. If it sticks open, your engine does not idle properly
Ford did a pretty good job with factory ignition coils. They work quite well until you get into high cylinder pressures, such as with supercharging or nitrous. A good rule is to replace factory ignition coils with 100,000 miles and five years of operation. It’s a good practice to replace coils whenever you replace spark plug wires. In fact, change spark plugs, wires, and coils all at the same time for best results.
Confusion abounds about Modular engine spark plugs. Original equipment on the 4.6L included two types of spark plugs on engines with twin coil-pack ignition. One cylinder bank had Motorcraft spark plugs with a platinum tip on the ground electrode while the opposite bank had the platinum tip on the center electrode. Ford equipped these engines in this manner to meet strict emissions standards for at least 50,000 miles.
Twin coil-pack ignition systems fire in opposite directions. Therefore, a spark plug’s spark leaps from the center electrode to the ground electrode on one side and from the ground electrode to the center electrode on the other, hence the platinum tip location. This provides a cleaner fuel burn for improved emissions. Replacement Motorcraft spark plugs have a platinum tip on the center electrode only.
Sean Hyland suggests the NGK-TR6 copper core spark plug for Modular engines because copper conducts electricity very well. He also suggests .035- inch gap on naturally aspirated engines and .030 inch on those that are supercharged. I suggest staying with what Ford recommends in your owner’s manual or factory service manual.
Although dyno tuning tends to be thought of as a speed and performance thing, it is also about proper tuning for power and reliability. If you’re building a Modular engine for street use only, your EEC should be in proper tune. Today’s electronically controlled engines have to be thought of in a different way. Instead of swapping jets and adjusting idle/air mixture screws in a carburetor, you have to sit down with a laptop computer and hone your ECM programming skills.
Check Fuel System
It’s a good idea to replace the fuel pressure regulator. If you’ve stepped up to hotter cams and deep-breathing heads, consider the installation of an adjustable fuel-pressure regulator. Ford specifies self-cleaning fuel injectors for Modular engines. This means you don’t need a fuel injector cleaner in the fuel tank, nor do you have to remove injectors periodically to clean them. It is always good to have a professional periodically inspect fuel injectors for proper spray pattern. Replace the in-tank fuel pump before starting the engine, especially if your vehicle has more than 100,000 miles.
Tuning an ECM is strictly for the professional, not something you should try to do yourself. The dyno tuning professional puts your Ford vehicle on a chassis dynamometer and runs it under wide-open-throttle conditions to dial-in the fuel and ignition curves. If you haven’t made any major changes to your Modular engine, dyno tuning isn’t required, but it is helpful to be absolutely certain of fuel and ignition curves.
Use the Best Ignition Wires
When you buy ignition wires for your Modular engine project, go for the best quality. These are Live Wires from Performance Distributors. Ford Racing and Motorcraft high-performance ignition wires produce outstanding quality that will go the distance.
Inspect All New Parts
This is a conventional non-resistor Autolite spark plug but it illustrates what I want to convey about spark plugs. Never simply install them right out of the box. Always check their gaps. This plug suffers from a cross-electrode smashing, which confirms why you must first inspect and check the gap. Always use platinum-tip spark plugs in a Modular engine. High-energy ignition systems demand it.
Use New Ignition Parts
Most Modular engines prior to 1999 have twin-coil pack ignition systems with spark plug wires. When you rebuild your engine, replace both coils and the ignition wires. Make sure you have done so before firing the engine. Coil-onplug ignitions should also receive new coils.
Dyno tuning is a must whenever changing camshafts, cylinder heads, fuel injectors, or anything else that changes the engine’s basic personality. When you upgrade to hotter cams or high-performance heads, it becomes necessary to upgrade fuel injectors, throttle body, and intake manifold. This means you have to change the fuel curve and the spark timing. Consider it money well spent and a good investment in your new engine.
Written by George Reid and Posted with Permission of CarTechBooks