AIR FILTRATION

If you have the budget, adding a HEPA (High-Efficiency Particulate Air) air filtration system is a great idea. A HEPA filter is designed to trap at least 99.7 percent of airborne particles down to 0.3 microns in size. A HEPA filter approach for a ceiling tile application includes a series of overhead HEPA filters with motorized fans (these mount in the ceiling tile areas in the ceiling grid, just as the tiles mount). The fans are located overhead of the filters. These draw air that is filtered and clean into the room. In order to balance room pressure, you also need vents to draw air out of the room.

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The COMP Cams billet aluminum belt tensioner is adjustable for belt tension and offers rock-solid serpentine belt guidance.

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After a few minor preparation steps, the engine ran on the dyno. How’s 625 horsepower sound?

by Mike Mavrigian

photos by author

Whenever I build an engine, regardless of my confidence in terms of fitting and assembly detail, I’m always a bit apprehensive when it comes time to light the fire. But when things go picture-perfect and you hit high numbers without a single glitch, it’s a feeling that’s better than sex (I’m sure you know what I mean). This LS program proved to be a total success.

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Block I.D. number generally on side of block above oil filter for blocks cast at Cleveland. Dearborn block I.D. number near distributor and above generator. Most Dearborn blocks used in trucks. No Dearborn blocks after 1957. There were no special truck blocks. Heavy-duty trucks with steel cranks used C1AE or C2AE car blocks.

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Story and Photography by John Mummert

The Ford Y-Block was introduced in 1954 to replace the well-know flathead. Displacement was unchanged at 239 cu. in., but the new engine had five main bearings, five cam bearings and overhead valves. Bore was 3.500″ and stroke was 3.100″ with 6.324″ connecting rods. Model year 1954 Mercury vehicles had a 256 cu. in. version with 3.625″ bore and 3.100″ stroke. Displacement was increased in 1955 to 272 cu. in. for most Ford car production. T-Bird and Mercury models got a 292 cu. in. version. The added displacement was achieved with a 3.625″ bore and 3.300″ stroke for the 272 and 3.750″ bore and the same 3.300″ stroke. The 3.100″ crankshaft is marked EBU, while the 3.300″ crankshaft is marked EC.

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Today’s CAD programs offer definitive X-, Y- and Z-axis depictions of specific blocks, providing you have access to these programs.

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This term is routinely misused and misunderstood.

by Mike Mavrigian

While seasoned engine builders understand what the term “blueprinting” means, chances are most of their customers don’t. Too many neophytes think that balancing and blueprinting go hand-in-hand. They blindly assume that if the crank has been ­balanced, that must mean that the engine has been blueprinted.

If you scan your local newspaper’s automotive classified section, you’re bound to see three or four ads offering “blueprinted” engines. They may be part of a restored muscle car or they may be offered alone, but, nonetheless, there they are, in black and white.
In 99 percent of the cases, the ads are probably wrong. We’re not implying that 99 percent of the folks who placed the ads are lying. Instead, we think these folks are generally misguided. A blueprinted engine represents an enormous amount of highly skilled labor, usually far beyond the average enthusiast’s understanding or budget. Just as the term “turbocharged” has been abused (turbo sunglasses, turbocharged golf balls, etc.), such is the case with engine blueprinting.

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all photos by author

An investment of a few hours during tube bending will pay off in achieving a neat and coordinated plumbing appearance.

The NOS nitrous pro fogger kit we installed features soft-plume-type fogger nozzles. In this view, the top inlet (in line with the discharge nozzle tube) is for extra fuel. The angled inlet is for the nitrous oxide feed. Each inlet port is labeled.

The foggers feature a discharge that’s positioned 90 degrees to the discharge tube. This soft-plume style requires that the outlet orifice faces inboard, toward the combustion chamber.

Because the intake manifold shown in this example did not feature bungs or adequate runner wall thickness to create sufficient threads, aluminum bungs featuring 1/16″ NPT threads were Tig-welded to the runners. Note how each nozzle is threaded into the bungs using a clock position that aims the nozzle outlet orifice directly toward the combustion chambers. In order to ensure this alignment, each nozzle was fully threaded into its bung. After an alignment matchmark was placed on each bung, the bungs were then welded in the proper clock position.

Both nitrous oxide and the required extra fuel supply are governed by individual solenoids. Each is color-coded-red is for fuel and blue is for nitrous.

Before cutting and bending the supplied stainless steel fuel and nitrous lines, be sure to slip the B-nuts and sleeves over the tube first. Here a red fuel line has been readied. Simply form a flare at the nozzle end of the tube and bend the line to the desired shape.

Here a blue nitrous tube is ready for nozzle connection. The tube sleeve features a slight chamfer that engages the backside of the tube flare. The flare seats onto the flare jet and the B-nut captures the assembly together for a leak-free seal.

The fuel (red setup on the left) and nitrous (blue on right) solenoids, distribution blocks and lines are seen here finished and ready for final installation.

Each inlet port of the nozzle requires a flare jet (much like jetting a carb). The NOS kit includes a selection and the manual offers jet combination suggestions based on the engine format.

For this application we fabricated an aluminum mounting bracket that fastens to the manifold and allows pass through for a -6 vacuum fitting to connect to a turbo wastegate. Both solenoids are mounted to this plate. Just for fun, we drilled a series of lightening holes in the plate and painted the plate with a metalflake base, cleared with a satin clearcoat.

This typical wiring connection illustrates the wiring for the solenoids, arming switch and microswitch.

When bending the stainless steel fuel and nitrous tubes, it only makes sense to attempt to achieve a neat and attractive appearance. We positioned the nitrous distribution block underneath the fuel block and formed our nitrous and fuel lines in parallel with each other.

The nitrous oxide bottle is plumbed to the nitrous solenoid via a supplied length of -6 AN stainless braided hose, already equipped with hose ends. An already-installed pressure gauge lets you easily monitor bottle pressure. The blowdown tube can be oriented to suit the in-car bottle mounting position.

This overhead view shows how the fuel and nitrous tubes follow the same bends. When viewed from either end (front-to-rear or rear-to-front), the horizontal runs of the tubes are aligned perfectly, giving the impression of only one set of tubes. It only takes a few more minutes to plan the tube bends and alignment, and the result provides not only function, but a pleasing form as well.

SOLENOID PLUMBING

As mentioned, two individual solenoids are involved, one for nitrous and one for the extra fuel shot. Loosely install a 1/8″ x 1/8″ NPT male nipple into the outlet port of the nitrous solenoid. Loosely install a 1/4″ NPT x 6AN nitrous filter into the inlet port of the nitrous solenoid. Trail-fit the solenoid, nitrous filter and the 1/8″ x 1/8″ NPT nipple into the nitrous distribution block. Note the orientation of the fitting and solenoid. Disassemble, coat the NPT threads with Teflon paste and reassemble, tightening the connections to achieve the desired mounting positions.

Perform the same procedure with the fuel solenoid, using the 1/8″ x 1/8″ NPT 90-degree fitting into the fuel solenoid outlet port and the 1/8″ NPT x 4AN fitting into the fuel solenoid inlet port.

When installing the nitrous bottle in a vehicle, pay attention when determining the route for the 12′ section of 6AN hose, making sure that it clears exhaust, suspension, steering, wheels, electrical lines, etc. Attach the 6AN nitrous supply hose to the nitrous bottle valve adapter.

Purge the nitrous supply line by wrapping the solenoid end of the hose with a clean rag. Point the hose away from yourself and others, and briefly open the bottle valve. Attach the nitrous supply hose to the nitrous solenoid inlet port.

NOS recommends that the primary fuel line for the nitrous system should be a dedicated supply to feed the nitrous system only. In other words, the nitrous system’s fuel line should be fed by a separate fuel tank/fuel cell. This will require a dedicated fuel pump and pressure regulator capable of handling the engine and system demands. If the nitrous system is under-fed or runs dry of fuel, and nitrous-only is injected into the engine, catastrophic engine failure is a certainty. In short, if the engine is wailing and you activate the nitrous system at WOT, and no extra fuel mixes with the nitrous, the engine will go “boom” and that’s the end of that.

While it may be OK to have manual control of the nitrous switch while the engine is on the dyno, when the system is in the vehicle, a microswitch must be used at the throttle body linkage, so that the switch makes contact and opens the system only at WOT.
The NOS kit includes this microswitch and an adaptable mounting bracket. A driver-activated NOS arming switch is to be mounted in the cockpit, allowing the driver to arm and ready the system.

WIRING THE SYSTEM: NOT A BIG DEAL

The NOS instruction manual provides a detailed step-by-step regarding wiring the system. Here’s an overall view of the wiring hookups: From battery positive, an orange wire with an in line fuse is connected to the system’s power relay via the system’s wiring harness connector. From the relay harness, a green wire goes to chassis ground. The harness blue wire runs to a two-wire connector that runs to both one of the fuel solenoid’s red wires and one of the nitrous solenoid’s black wires. The extra black wire from the nitrous solenoid and the extra red wire from the fuel solenoid both go to ground.

The relay harness red wire runs to the microswitch. From the microswitch, a wire is connected to the No. 2 terminal of the arming switch. The No. 1 terminal of the arming switch goes to ignition-switched 12 volts and the No. 3 arming switch terminal goes to ground.

TROUBLESHOOTING

Problem: No change in engine speed when the fuel solenoid is activated.
Cause: System is wired incorrectly; the fuel line is restricted; or the fuel solenoid has malfunctioned.

Problem: Change in engine speed when the nitrous bottle valve is opened.

Cause: Malfunctioning nitrous solenoid.

Problem: Engine runs rich when the system is activated.

Cause: The bottle valve is not fully opened; low bottle pressure; the bottle is mounted improperly; the nitrous filter is plugged; mismatched nitrous/fuel jetting; excessive fuel pressure; loose nitrous solenoid wiring; or malfunctioning nitrous solenoid.

Problem: No change in performance when the system is activated.

Cause: The system is wired incorrectly; loose ground wire(s); malfunctioning push button; no power to the arming switch or malfunctioning arming switch; malfunctioning microswitch; or overly rich fuel condition.

Problem: Engine detonates mildly when the system is activated.

Cause: Excessive ignition timing; inadequate octane fuel; spark plug hat range too high; too much nitrous flow; inadequate fuel delivery due to plugged fuel filter; crimped fuel line; or weak fuel pump.

Problem: High-rpm misfire when system is activated.

Cause: Excessive spark plug gap; or weak ignition (check all ignition system components).

Problem: Surges under acceleration when system is activated.

Cause: Inadequate nitrous supply (check bottle weight); or bottle mounted incorrectly.

NITROUS SYSTEM SAFETY TIPS

1. Never attempt to start the engine if the nitrous has been injected while the engine was not running, as this can result in an explosion. Disconnect the coil wire and turn the motor with wide-open throttle for several revolutions before attempting to start.
2. Never permit oil, grease or any other combustible substances to come into contact with cylinders, valves, solenoids, hoses or fittings. Oil and certain gases (such as oxygen and nitrous oxide) may combine to produce a flammable condition.
3. Never interchange solenoids or other components that are used for one gas with those used for another gas. Doing so may result in an explosion.
4. Never change the pressure settings of nitrous bottle safety valves. Increasing the safety valve pressure settings may create an explosive bottle condition.
5. Be sure to identify the gas content on the NOS label on the bottle before using. If the bottle is not identified regarding the gas contents, return the bottle to the supplier.
6. Do not deface or remove any markings that are used for bottle content identification.
7. Nitrous bottle valves should be closed when the system is not in use.
8. Keep valves closed on empty bottles to prevent accidental contamination.
9. After storage, open the nitrous bottle valve for an instant to clear the opening of any possible dirt or dust.
10. Never force threaded connections. It’s important that all threads on valves and solenoids are properly mated.
11. Only use nitrous oxide at wide-open throttle and at engine speeds above 3,000 rpm.
12. DON’T use Teflon tape to seal NPT threads when installing nozzles, distribution blocks or solenoids! Instead, use Teflon-based paste. Small bits of excess tape may enter the system, causing a restriction that can result in catastrophic engine damage.
13. Don’t inhale nitrous oxide! Death due to suffocation can occur. Also, don’t let nitrous oxide contact your skin since this can result in severe frostbite.
14. Don’t use octane boosters that contain methanol. This can result in damage to the fuel solenoid, which can lead to catastrophic engine failure.
15. Don’t allow nitrous pressure to exceed 1,100 psi. Excessive pressure can cause swelling or failure of the nitrous solenoid plunger.

For more information on NOS Nitrous Oxide Systems, call (800) 652-0406, ext. 16414.

INSTALLING NITROUS

Here we detail a nitrous setup on a specific application, using a Honda performance engine as our example.

by Mike Mavrigian

What is nitrous oxide? Nitrous oxide is a cryogenic gas composed of nitrogen and oxygen molecules, and is comprised of 36 percent oxygen by weight. Nitrous oxide alone is non-flammable and is stored as a compressed liquid. Two distinct grades of nitrous oxide exist-U.S.P. and Nitrous Plus. U.S.P. is medical-grade nitrous oxide commonly used in dental and veterinary anesthesia, and is not available to the general public. Nitrous Plus is intended for automotive applications and contains trace amounts of sulfur dioxide to prevent substance abuse (this stuff will make you happy when you whap the throttle, as opposed to inhaling it).

In automotive applications, a combination of Nitrous Plus and fuel is injected into the engine’s intake manifold, which lowers the intake air temperature, producing a dense inlet charge. Nitrous Plus/fuel also increases the inlet charge oxygen content (air alone is only 22 percent oxygen by weight). This nitrous/fuel induction increases the rate at which combustion occurs. Basically, it’s a steroid to boost combustion, elevating cylinder pressure and cylinder temperature while increasing the combustion rate.

Direct-port style injection kits are intended to provide maximum performance and tenability. Horsepower increases from these kits will vary with engine displacement and configuration. Approximate power increases can be estimated based upon the massflow of nitrous into the engine. The preceding table provides the power increases that can be expected on a typical engine.

The system shown here is the NOS Pro Fogger kit (P/N 04430), a single-stage system intended for maximum-effort competition engines only. NOS (the maker of this system) suggests several engine upgrades if you intend to increase engine output by more than 40-50 percent. These include the use of forged pistons, forged or steel billet or aluminum connecting rods, main support (girdles, sleeves) and cylinder head studs to resist cylinder head lifting. A high-output ignition system is also strongly recommended.

FUEL PRESSURE CAUTION

Adequate fuel delivery and pressure is an absolute must. Fuel pumps and lines should be able to flow at least 0.1 gallon per hour, per horsepower at 6 psi (for carbureted applications) or at system pressure in a fuel injected engine. For example, at 42 psi flowing, a motor that produces 450 horsepower while the nitrous system is activated will require at least 45 gph at 42 psi flowing at WOT (wide open throttle).

Note that aftermarket pumps may be rated under free-flowing conditions and at system pressure their flow rates may be reduced. Check the fuel pump maker’s specs carefully or have the pump checked before using it. EFI jetting is applicable to vehicles that operate at 40-40 psig at WOT.

MANIFOLD PREP

While many intake manifolds feature already-tapped holes to accept nitrous nozzles, or feature blank bosses that can readily be drilled and tapped, some intakes require welding bungs onto the runners. The specific intake manifold shown here is a “sheet metal” welded aluminum manifold with no provision for tapping (the manifold runners were not thick enough to accommodate tapped 1/16″ NPT holes), so a set of aluminum bungs were welded onto the runners. The bungs feature 1/16″ NPT female threads to accommodate our nozzles.

BASIC CONNECTIONS/PLUMBING

The 12′ -6 AN hose (supplied) connects to the bottle, using the bottle valve adapter and sealing washer. The -6 hose then connects to the nitrous solenoid side inlet. The nitrous solenoid connects to and feeds a distribution block.

Stainless steel hard lines route nitrous to each fogger nozzle (in our Honda’s case, we have one nozzle per cylinder), which is threaded into each intake runner.

In addition to the nitrous charge, the system also requires an additional fuel feed since a combined nitrous and fuel charge is delivered when the system activates. The “Cheater” fuel solenoid is fed by a fuel source (preferably a separate and dedicated fuel tank), and connects to and feeds another distribution block. Stainless steel lines route from this fuel block to each nozzle.

The fogger nozzles feature two inlet ports (one for nitrous and one for fuel, each of which are labeled) and a single outlet nozzle that outputs the combined nitrous/fuel charge into the intake runner.

The nozzles may be of the annular or soft-plume type. Annular nozzles output at the tip of the nozzle. Because of this directional output, the nozzle must be installed at an angle to aim the charge toward the intake port. The soft-plume nozzle features a directional (90-degree) output, allowing the nozzle to be installed 90 degrees to the intake port.

The nozzles feature male 1/16″ NPT threads. If the intake manifold runner walls are thick enough (for example on a cast aluminum unit), simply drill a 1/4″ hole and use the kit-supplied 1/16″ NPT tap to create threads. If the runner walls are not thick enough, custom bungs can be welded to the runners. In either case, be sure to tap the 1/16″ NPT holes just deep enough to allow the discharge orifice to protrude into the runner. If the hole is tapped too deep, the NPT nozzle threads may not seal.

When soft-plume nozzles are used, pay attention to nozzle orientation (clock position) when installing, making sure that the discharge orifice aims toward the intake port.
Once the nozzles are installed into the manifold (and you’ve decided where the solenoids and distribution blocks will be located), you’ll need to make the nitrous and fuel feed tube assemblies. The kit includes a batch of 12″ long stainless tubes, connection features flares, tubing sleeves and barrel nuts where the lines connect to the nozzles, and straight-end (no flare) and brass compression fittings where the lines connect to the distribution blocks. The nozzle-end tube sleeves and barrel nuts are color-coded-red is for fuel and blue is for nitrous.

The tube lines must be cut to length, flared at the nozzle end and bent according to the individual application, both for fit and for aesthetics. For this task, you’ll simply need a tubing cutter, a flaring tool and a tubing bender. No surprises here.

Since appearance is an important consideration, it may be best to first mock fake lines using scrap tubes or coat hanger wire to finalize your lengths and shapes. Just remember to slip the tube sleeves and tube nuts onto the tubing and butt them up against the flared ends before any sharp bends are made, otherwise you won’t be able to slide the tube sleeves and nuts over the bends. Note: The brass compression fittings are supplied with the distribution blocks. They’re held captive inside the distribution block’s tube nuts, so be careful when you remove the nuts to avoid dropping the compression fittings.

As you’re fitting the lines, be sure to select and install the supplied flare jets into the feed ports of the nozzles for both fuel and nitrous. All jets are marked for size, but the markings can be very difficult to see. I suggest having a magnifying glass handy to identify each. With the jets installed into the nozzles, you can design and install the tubing assemblies.

While many installers rely on the stainless nitrous and fuel lines to support the distribution blocks and solenoids, we opted to fabricate a mounting bracket that provides support from the intake manifold plenum.

The bracket (a wing-shaped piece cut from 1/8″ high-temper aluminum) is mounted directly to the intake manifold at the extra-thick welded-on base plate that the Venom intake features for vacuum connections. This plate thickness is about 0.185″. We drilled two 0.1360″ blind holes and tapped these at a depth of 0.170″ using an 8 x 32 bottoming tap. The plate is then attached using a pair of 8 x 32 stainless socket head bolts with a shank length of 0.340″. The individual nitrous and fuel blocks and solenoids are attached to this bracket.

Just for giggles, we also drilled a series of “lightening” holes in the bracket for added visual appeal. Whenever given a choice, we tend to always choose the more time-consuming approach, mostly because we’re just plain goofy.

Note: When you assemble the solenoids to the distribution blocks and the tubing to both the blocks and nozzles, pay attention to thread sealing. Apply Teflon-based thread paste to all of the fuel and nitrous fittings that screw into the solenoids, to the feed fittings that connect the solenoids to the distribution blocks and to the nozzle threads where they screw into the manifold. Do not use Teflon tape, since there’s a chance that small pieces of tape can accidentally enter the system. Always use Teflon paste instead.

Don’t use any additional sealer at either end of the tubes. The compression fittings and nuts will seal the distribution block-to-tube connections and the flared AN connection at the tubing-to-nozzles will take care of that seal. Only apply thread sealant to pipe threads.