Any self-respecting Ford enthusiast will be somewhat familiar with centrifugal superchargers. The premise is simple, even if the execution is not. Air molecules have enough mass and weight so that if you build a device to propel them from point A to point B quickly enough, they’ll tend to keep moving in that direction. If you trap these molecules inside an intake manifold, static pressure will build. Centrifugal superchargers use an impeller to do the propelling.
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If you think about the term “centrifugal” in terms of a supercharger, you might think it must take one hell of a spin to thrust air into an engine with anything more than atmospheric pressure. The impellers used on either turbochargers or centrifugal superchargers require high tip speeds to compress air. Tip speed is relative to the diameter of the impeller, requiring higher RPM for smaller diameters, or a lower RPM for a larger diameter, to attain a given tip speed.
There are two practical ways to spin an impeller at such high speeds:
- With a turbine, as used in a turbocharger and described elsewhere in this book.
- Mechanically, using power from the engine’s crankshaft and a method of compounding it from a few-thousand RPM to tens-of-thousands RPM at the impeller. This is how it’s done in a centrifugal supercharger.
An impeller should be a masterpiece, incorporating the results of many sciences. To work well, this core part of a centrifugal supercharger must be designed around a detailed understanding of airflow dynamics, material properties, and careful machining techniques. If any of those areas are overlooked, the supercharger in question will not provide the anticipated performance, or it may just fail entirely.
Impeller design is very important because of its extremely high operational speed – up to 60,000 rpm in some applications. Another factor is efficiency; the shape and contour of the blades and voids determine its ability to accelerate air within a specific range of rotating speeds. In this particular aspect, the shape of the housing that surrounds the impeller, referred to as the volute, is critically important for the impeller to achieve its intended efficiency.
The basic centrifugal supercharger design has been used to supercharge engines almost since the appearance of the four-stroke engine itself. Innovators like Indy 500 great Harry Miller took impeller design to its practical limits in automotive and marine racing engines as early as the 1930s. For Miller’s famed and fabled 750-hp Novi V-8 (originally commissioned by a Novi, Michigan, Ford dealer), the 10-inch impeller enlisted turned at a speed that caused the outer tips of the impeller blades to travel at Mach 1.6.
Impossible? Well, because the impeller was moving so much air, the density around those supersonic tips was high enough to prevent the shock waves that destroy most metal parts moving at that high a speed.
At the point where air is delivered from the impeller circumference to a diffuser, its mass has been accelerated and its volume reduced. In other words, the air has been (greatly) compressed. In a reverse of the venturi principle, a diffuser provides an increasing crosssectional area for the air, slowing it down and increasing its static pressure. The compressed air will only move back through the impeller if the tip speed drops significantly or if the static pressure on the intake tract exceeds the pressure change across the impeller.
The relationship between impeller speed and how efficiently it will accelerate an incoming air mass is governed largely by:
- The shape of the impeller blades and the cavities among them.
- The shape of the impeller housing and the diffuser cavities.
- Clearances between the impeller housing and the impeller’s blades.
- The positioning of the impeller and the housing surface behind it.
Every impeller design has a speed range where it’s highly efficient at moving air. With today’s computer-aided design (CAD) and automated profile machining, these RPM ranges tend to be fairly wide, but that wasn’t always the case. Incredible as it may seem, Harry Miller was forced to experiment with a lengthy series of one-off impellers, each one an investment casting requiring many hours of finishing and balance work, before he discovered one with the right contours to suit the available drive speed of the Novi racing engine.
Within the sweet spot of an impeller’s efficiency range, the dynamic sealing between the blades and housing improves to the point where the system begins to seriously tax the inlet airflow characteristics and whatever might follow the supercharger in the sequence of intake components. This means that when the blower starts to get in its performance curve, anything in the rest of the intake tract that can’t handle the flow will seriously compromise the net effect of the supercharger. While this is true regardless of the general type of supercharger installed on an engine, it is particularly true with the centrifugal types because of the remarkable change in airflow that can take place with a very small change in engine speed.
This effect is similar to – but not nearly as dramatic as – the radical shift in performance that occurs when the impeller of a turbocharger enters its sweet spot. During these transitional periods, the airflow through the entire intake tract changes drastically, which is why something as simple as a loose air filter element or an intermittent leak in ducting can wreak havoc with the engine’s air-fuel metering, especially with EFI or SEFI systems.
During the mid-1950s, Robert Paxton McCulloch first sold small centrifugal superchargers that could be installed on automotive engines without too much difficulty. Paxton’s reciprocatingball drive blowers were homologated for use in NASCAR by Ford Motor Company, who offered a similar application for their 312-ci engines and made them available in the two-seat, ’57 Ford Thunderbird and a limited number of full-size Ford models.
These early units differed in one specific sense, according to Craig Conley of Paradise Paxton, a division of Paradise Wheels Inc. “Although both units incorporated a ball-type drive mechanism, the NASCAR units had what amounted to a direct drive for the impeller, while the street versions used oil pressure to exert variable tension on the outer races of the drive, allowing engine speed to somewhat regulate how effectively the impeller was driven. Higher oil pressure brought about a change in drive ratio in the ball drive, and the impeller speed went up accordingly. It was the ball drive that eventually became the obstacle for those seeking higher boost pressures. The ball-drive units are perfect for anyone looking to generate 7 lbs of boost or less – they’ll do that quietly and reliably. Above that manifold pressure, the impeller should be driven by a more direct method, such as the modern gear drive units.”
Using a gear system, like the one used in Paxton Novi superchargers, to drive the impeller is one way to eliminate slippage and impeller speed loss within the supercharger itself. While both designs (reciprocating-ball and gear drive) are actually belt driven from the crankshaft (so there’s one over/underdrive ratio there), the extreme overdrive ratio required to attain the proper impeller speed happens within the supercharger housing itself.
The precise origin of the gear-driven centrifugal supercharger remains a hotly contested point. Of course, Harry Miller’s Novi supercharger was turned by a beautifully crafted gear drive that linked one of the camshafts to the impeller.
Robert Paxton McCulloch also built a gear-driven centrifugal supercharger around 1937, which pre-dates his reciprocating ball design (originally developed in 1943 as an air pump for the U.S. Navy) by almost half a decade. However, Paxton’s crankcase lubricated, gear-driven model for the Ford Flathead V8-60 was noisy and deemed impracticable from a mass-production standpoint.
Others also tried it with limited success, and it wouldn’t be until the early 1990s when Vortech Engineering LLC popularized the gear-driven centrifugal supercharger, changing the face of the street supercharger industry.
The Paxton ReciprocatingBall Drive
In the past, Paxton superchargers used a unique ball drive to overdrive the impeller relative to the size input pulley and shaft speed. The impeller turned approximately 4.4 times faster than the input shaft speed. The drive arrangement is nearly silent, which is a significant difference from the gear-drive units. It’s a relatively simple drive system, but its operation is often confusing to grasp.
Paxton’s ball drive was an important feature of the units built by the company to circulate air inside America’s submarines during World War II and later in nuclear submarines. In that application, even very small mechanical noises are telegraphed through the hull of a ship into the surrounding water, immediately revealing the boat’s position to a potential enemy.
The input shaft on a silent-drive Paxton supercharger drives a precisioncast separator with drive lugs positioned between the balls. The balls are contained in a stationary two-piece outer race. The race is split along the circumference, and the two sections are springloaded together with considerable force. The spring loading between the two sections of the outer race creates pressure between the ball surfaces and the impeller shaft to spin the impeller efficiently without using drive gears.
To accomplish this, the impeller shaft features a concave section to accommodate the balls, which exert considerable pressure against the shaft, thanks to the spring-loaded outer ball race. Because the balls capture the impeller shaft, it rotates at their surface speed – resulting in an impeller speed that is about 4.4 times the speed of the supercharger’s input pulley.
The actual overdrive ratio is calculated by comparing the circumference of the outer race (at the point where the balls contact it) with the circumference of the concave section of the impeller shaft. From a math-geek’s standpoint, however, the ratio is much more complicated, because the balls, outer race, and impeller shaft do not present a system with clearly defined contact points. The balls contact the impeller shaft (and the outer race) across an arc, or segment, of their outer surface, rather than a single point on any of the diameters.
Adding to the confusion, this contact area is somewhat affected by the RPM of the system. At very high rotational speeds, the balls get “heavier” against the surface of the spring load between the two outer race sections. This has the effect of further altering the contact areas and reducing the overdrive ratio by a very small amount.
Paxton Products: The Early Years
The product name “McCulloch” pre-dates the “Paxton” trade name by some three years. After perfecting his reciprocating-ball design air pump, which served the U.S. Navy so well (and more sophisticated versions of the original design still do), Robert Paxton McCulloch took $700,000 in research money and set up shop in Los Angeles, California. His first product was the McCulloch VS-57 supercharger, released in 1953.
Close to 46,000 McCulloch VS-57s were produced, and the unit achieved notoriety, as well as some degree of success, on cars like the 1954 Kaiser Manhattan, the 1956 Studebaker Golden Hawk, the 1957 Packard Clipper, and the 1958 Packard Hawk.
In 1956, McCulloch set up a special automotive service parts division known as Paxton Products. That same year, the company released a new variable-rate supercharger known as the VR-57, which featured a step ratio from 3.5:1 to 5.5:1, achieved by a spring pack that would change the distance between the ball races based on engine RPM. This is the same supercharger that was briefly used in NASCAR competition, as well as being used on some 211 ’57 Ford “Blower Birds.”
In 1958, Andy Granatelli set numerous land speed records at the Bonneville Salt Flats driving a Paxton SN-60- equipped Studebaker Hawk. That same year, Andy, Vince, and Joe Granatelli purchased Paxton Products. The Granatellis wanted to service and maintain the manufacturer’s government contracts with the military, to maintain the company’s lucrative automotive replacement parts business, and perhaps sell a little new product here and there.
In 1965, Paxton was again vaulted into the automotive limelight when Carroll Shelby teamed up with them first on a blown ’65 289 Shelby Mustang and later on a twin-blown 427 Cobra, which Carroll personally sold to comedian Bill Cosby, but it was never made a production item. The Paxton supercharger option was produced in limited quantities on Shelby GT-350 Mustangs from 1966 to 1968. This setup was also available as an over-the-counter, dealerinstalled option on standard small-block V-8 Mustangs from 1965 to 1972.
In the gloomy 1970s, Paxton focused on other markets, yet continued to sell the SN-60 and related service components. Then, in 1979, Ford came out with the Fox platform Mustang. Paxton immediately responded with their compact, SN-60-based kit designed for the carbureted 5.0L.
Ford changed all that in 1986 with the newly re-engineered 5.0L Mustang LX and GT models, which featured Sequential Electronic Fuel Injection (SEFI). Paxton Products was the first aftermarket supercharger manufacturer to release a 50-state-legal street supercharger kit using an updated version of their SN-60 reciprocating-ball-drive supercharger known as the SN-89. In essence, the EFI Mustang and the Paxton SN-89 (later updated to SN-92, SN- 93, SN-95, and SN-2000 versions) basically rewrote the book on emissions-legal street supercharging.
The New Kids on the Block
At this point, let’s introduce a handful of “new players” into the fold. In 1992, Paxton engineers Jim Middlebrook and Jim Wheeler left Paxton Automotive Products and founded Vortech Engineering. Vortech Engineering became the first manufacturer in the street blower business to introduce a helical cut, gear-driven, crankcase oillubricated centrifugal supercharger to the mass market with the release of their emissions-legal Vortech V-1A. Middlebrook and Wheeler realized the shortcomings of the Paxton ball- drive design, while recognizing a VERY healthy market, and had done their homework on the significant challenges in manufacturing a saleable product.
Vortech realized that the largest of these obstacles was building a gear drive that could operate at very high speed and remain reasonably quiet. The answer came from an existing technology, as is often the case when performance enthusiasts adapt this or that looking for more horsepower.
Vortech found what it was looking for in a gear-cutting firm that made parts for helicopter gearboxes. Although fairly simple in appearance, gears are extremely sophisticated in terms of their tooth profiles, balance, and surface finishes, especially when intended for highspeed applications. In order to build the gear drivetrain Vortech had in mind, the teeth of the larger input gear and smaller impeller gear required very precise machine work to keep them from sounding like a police siren.
With the release of the V-1A, Vortech became the first to bring a geardriven centrifugal supercharger to the mass market. Vortech simultaneously released their 5.0L late-model Mustang and their 7.5L (460-ci) Ford F-150/F- 250 truck street blower kits. They have never looked back.
The structure of the new company changed approximately one year later after a falling-out between Wheeler and Middlebrook. In his departure, Jim Wheeler started up his own company, Wheeler Racing-Powerdyne Automotive Products, Inc., producers of the Powerdyne BD-10 (and later BD-11) silent-drive centrifugal street superchargers. These Powerdyne blowers sort of resemble a Paxton or Vortech in appearance, but are internally totally different in design.
Internally, the Powerdyne BD-10 differs from the Vortech V-1A in that it uses an internal cog drive belt (much quieter) rather than high-pitch helical-cut drive gears. It also uses ceramic ball bearings and is 100 percent self-lubricating.
In order to keep critical start-up money and cash flow on the positive side, Powerdyne private labeled its new silent running BD-10 to B&M Performance Products with the release of its BD-10-based street blower model.
Powerdyne also attracted the attention of Ford Special Vehicle Engineering (SVO) a.k.a. Ford Motorsport, largely due to the fact that the BD-10 was 100 percent self-contained. This appealed to Ford because a customer could install one of these 50-state-exempt street blowers on any 1986 to 1995 5.0Lequipped Mustang or any 1996 to 2001 5.0L Ford Explorer or Mercury Mountaineer SUV without negating any manufacturer’s warranties.
Another new arrival was Accessible Technologies, Inc. (ATI) with their 50- state-legal ATI ProCharger self-contained, gear-driven supercharger for the 1986 to 1993 5.0L Mustangs. In essence, the ATI ProCharger featured the best of both worlds. The unit was self-lubricating like the Powerdyne BD-10, but it also possessed the reliability and strength of precision-ground steel-drive gears like the Vortech V-1A trim.
Is it Paxton, or is it Paxtons?
Initially that query may be pretty confusing, but like everything else in life, there is a point. In 1998, investor David Adams Jr. purchased all the corporate assets and production rights to the Paxton Supercharger from the Granatelli family. Adams was a businessman first and a car enthusiast second, and his primary intent was to regain the company’s rightful market share, which it had been steadily losing to the likes of Vortech, Powerdyne, and other new manufacturers.
In order to do that, Adams realized that Paxton had to create an all-new product that could go head-to-head with the top-selling Vortech V-Series product line. The Novi gear-driven supercharger, so named after the Granatelli-owned Novi Indianapolis 500 racecars, was already on the drawing boards. Adams was also keenly aware that it was going to take a sizeable amount of capital to finance such a project, and took stock of the company’s assets. Since the original Paxton ball-drive SN-60 design had seen its day, he brokered the sale of the product line to well-known Shelby restorer and vintage Paxton and McCulloch supercharger tuner/rebuilder Craig Conley of Paradise Wheels Inc. Conley received the remaining inventory, all engineering rights, and the entire original tooling from those earlier units.
“Actually, there really wasn’t anybody taking over the rebuilding of the McCulloch and Paxton superchargers,” said Conley. “Since I had a passion for the vintage Shelby Mustangs, I started rebuilding these units on my own back in the early 1980s without actually being an authorized Paxton dealer.
“Once Paxton got wind of the fact that I was rebuilding these units on my own, and had a real good success rate with these blowers, a gentleman who worked for Paxton named Brian Berry contacted me and asked me if I would be interested in coming up and doing sort of a ‘cross training’ program with their engineers. Paxton had been having some reliability problems recently with their SN-Series blowers, and thought that perhaps I might be able to help out.”
That initial introduction opened the door for Conley. Before too long, Craig began working on some joint engineering projects with the manufacturer, and in fact, the factory was actually sending some of their warranty repairs directly to him.
“Paxton was kind of winding down their SN-Series reciprocating-ball-drive blower program and getting into their Novi gear-drive blower program because that’s what everybody wanted. I was asked if I would be interested in taking over the McCulloch and SN-Series parts, sales, and repair business from the years 1953 to 2000. In a nutshell, I was just at the right place at the right time!”
However, as good as the Paxton Novi 1000 and 2000 gear-drive blowers were, and are, the monumental expense of bringing these products to market proved a bit too much for the company. In late 2001, Paxton Automotive Products and Vortech Engineering LLC entered into what was officially called a “strategic partnership,” where the two product lines were consolidated under the Vortech Engineering LLC corporate umbrella.
THE STATE OF THE CENTRIFUGAL SUPERCHARGER INDUSTRY
Accessible Technologies, Inc. (ATI)
ATI’s ProCharger took the 5.0L pushrod V-8 ranks by storm in 1994 with the release of the P600 gear charger, which produced up to 17 psi! The company next released the P600B, making it the first gear charger over 5- to 8-psi to be awarded a 50-state-legal exemption.
ATI next came out with the D-1 race blower in 1998, which holds the distinction of powering the first “Pro 5.0L” Mustang into the 7s (7.60 at 185 mph).5.0L and 4.6L supercharger kits. ATI ProCharger also offers two kits for the popular 3.8-liter Mustangs. ATI ProCharger has introduced a new street supercharger kit for the 3-valve 4.6L 2005 Mustang GTs. Carbureted Ford small-block owners will be happy to learn that ATI ProCharger also manufactures a kit for the 289/302 and 351W small-block engines.
1999-2001 V-6 Mustang, p/n 1F1212-SCI, 9-psi w/P-1SC
1994-1998 V-6 Mustang, p/n 1DJ212-121, 9-psi w/P-1SC
1986-1993 V-8 Mustang, p/n 1FAO11-SC, 6-20- psi, w/P-1SC
1986-1993 V-8 Mustang, p/n 1FA212-141, 9-14- psi w/600B or P-1SC
1986-1993 V-8 Mustang, p/n 1FA214-SCI, 14- 20-psi w/P-1SC
1986-1993 V-8 Mustang, p/n 1FA324-D1, 17-25- psi, w/D-1 or D-1SC
1994-1995 V-8 Mustang, p/n 1FBo11-SC, 6-15- psi w/P-1SC
1994-1995 V-8 Mustang, p/n 1FB324-D1, 15- 22-psi w/D-1 or D-1SC
1982-1985 V-8 Mustang, Same as ’86-’93 5.0L
1999-2001 Mustang GT, p/n 1FE212-081, 8-psi w/P-1SC
1999-2001 Mustang GT, p/n 1FE212-121, 10- 12-psi w/P-1SC
1996-1998 Mustang GT, p/n 1FD212-101, 8-10- psi w/P600B or P-1SC
1996-1998 Mustang GT, p/n 1FD212-121, 10- 12-psi w/P-1SC
1996-2001 Mustang 2v/4v, p/n 1FX204-D1, Race Kit w/D-1SC
1996-1998 Mustang Cobra, p/n 1FC212-061, 6- psi w/P600B or P-1SC
1996-1998 Mustang Cobra, p/n 1FC212-101, 10-psi w/P600B or P-1SC
1999 Mustang Cobra, p/n 1FF212-061, 6-psi w/P-1SC
1999 Mustang Cobra, p/n 1FF212-101, 8-10-psi, w/P-1SC
Accessible Technologies, Inc.
14801 West 114th Terrace
Lenexa, KS 66215
Phone: (913) 338-2886
Fax: (913) 338-2879
Ford Racing Technologies
FRT offers a total of seven street blower applications based on the Powerdyne BD-11 self-lubricating, self-contained centrifugal supercharger, available for both the 1986-1995 5.0L Mustang (except Cobra) as well as the 1996-2001 5.0L Ford Explorer and Mercury Mountaineer, and 1993-1995 5.8L SVT Lightning pickup. Some are 50-state-legal, while others are not. They are:
1986-1993 5.0L Mustang except SVT Cobra (6- psi), p/n M-6066-A50
1986-1993 5.0L Mustang except SVT Cobra (9- psi), p/n M6066-A51*
1994-1995 5.0L Mustang except SVT Cobra (6- psi), p/n M-6066-B50
1996-1997 5.0L Explorer & Mountaineer (6-psi), p/n M-6066-E50*
1998 5.0L Explorer & Mountaineer (6-psi), p/n M- 6066-E51
1999-2001 5.0L Explorer & Mountaineer (6-psi), p/n M-6066-E52
1993-1995 5.8L SVT Lightning (6-psi), p/n M- 6066-T51
*Not legal for sale or use on pollution-controlled motor vehicles.
Paxton Automotive Products
Although Paxton Automotive Products, Inc. is now owned by Vortech Engineering, LLC, it operates as a separate entity. In 1998, Paxton entered a new chapter in its storied history when it replaced the aging SN-60-based, reciprocating-ball drive supercharger with the Novi 1000 and Novi 2000 standard rotation and reverse-rotation gear-driven superchargers.
The Novi 1000 was designed to appeal to the sport-compact enthusiasts as well as V-8 enthusiasts. It’s capable of producing a wide range of boost using various-sized pulleys, with a maximum boost rating of about 12 to 15 psi.
On the other hand, the Novi 2000 centrifugal supercharger was designed for up to 27 psi, while delivering up to 700 horsepower. The Novi 2000 RR was specifically designed for use on the 4.6- liter Mustang GTs and SVT Cobras, and is the largest, most powerful reverserotation centrifugal supercharger available. Both of these blowers are available in either satin or polished finish.
Paxton has also just released their Novi 1200 model to cover the mediumoutput street applications (71 ⁄2 psi), such as vintage street machines like the Shelby GT-350.
Also available is the race-only Novi 3000, which is reported to feature a 40 percent larger volute than the Novi 2000 model, with a whopping 5-inch inlet diameter and a 31 ⁄2-inch discharge tube. This blower also featured a 3.54:1 step-up ratio, cryogenically treated internal moving parts for extra strength, a 201-alloy cast-aluminum impeller, and billet-steel helical-cut gears. Like the Novi 1000 and 2000 models, the 3000 is available in either standard drive or reverse rotation in either satin or polished finish.
1986-1993 Novi 2000 5.0L H.O. Mustang V-8, p/n 1001810
1994-1995 Novi 2000 5.0L H.O.
Mustang/Cobra, p/n 1001812
1996-1997 Novi 2000-RR 4.6L SOHC Mustang GT, p/n 1001813
1999 4.6L Novi 2000-RR 4.6L SOHC Mustang GT, p/n 1001815
2000-2004 Novi 2000-RR 4.6L SOHC Mustang GT, p/n 1001822
1996-1998 Novi 2000-RR 4.6L DOHC SVT Cobra, p/n 1001814
1999-2004 Novi 2000-RR 4.6L DOHC SVT Cobra, p/n 1001816
2005 Novi 2000-RR 4.6L SOHC 3-valve Mustang GT, p/n 1001851 (satin), p/n 1001851-P (polished)
1964-1968 Novi 1200 carbureted Mustang/Cougar/Comet/Falcon/Fairlane 260-302, passenger-side mount, p/n 1001839 (satin), p/n 1001839-P (polished)
1964-68 Novi 1200 carbureted Mustang/Cougar/Comet/Falcon/Fairlane 260-302 driver-side mount, p/n 1001840 (satin), p/n 1001840-P (polished)
1969 Novi 1200 carbureted Mustang/Comet/Falcon/Fairlane 351W passenger-side mount, p/n 1001843 (satin), p/n 1001843-P (polished)
1969 Novi 1200 carbureted Mustang/Cougar/Comet/Falcon/Fairlane 351W driver-side mount, p/n 1001844 (satin), p/n 1001844-P (polished)
Paxton Automotive Products, Inc.
1300 Beacon Place
Channel Islands, CA 93033-9901
Phone: (805) 487-3796
Fax: (805) 247-0669
Earlier in this chapter, we discussed Craig Conley from Paradise Paxton, a division of Paradise Wheels, Inc., who acquired the production rights and ownership of the Paxton SN-60 family. Conley and his staff are experts at rebuilding both the McCulloch VS Series and Paxton SN Series centrifugal blowers. They not only rebuild customer cores, but they also offer brand new, Paxton SN- 60-Series kits for 289/302 engine Shelbys and Mustangs, as well as their SN-2000- based 1986-1993 5.0L kits.
“Our vintage street supercharger kits for the 1965-1968 Shelbys and Mustangs feature the classic Paxton SN-60 outer case with up-to-date SN-2000 internal components, so you basically get the best of both worlds,” says Conley.
Also big news is Paradise Paxton’s new Twin Paxton supercharger kit for 1965 to 1970 289/302 V-8s available in either two-stage, single 4-barrel applications, or straight blow-through dual-quad applications. Listed below are the kits Paradise Paxton offers. Since the product line is limited to a total of five (5) kits, there are no officially assigned part numbers.
1966-1967 SN-2000 carbureted kit for 289 Shelby GT350 and Mustang
1967-1970 SN-2000 carbureted kit for 289/302- engine Shelby GT350 and Mustang
1986-1993 5.0L EFI Mustang LX and GT and 1993 SVT Mustang Cobra
1965-1970 two-stage, single-quad twin-supercharger kit for Shelby/Mustang/Falcon/ Fairlane V-8s
1965-1970 straight blow-through dual-quad twinsupercharger kit for Shelby/Mustang/ Falcon/Fairlane V-8s
A division of Paradise Wheels, Inc.
920 Rancheros Drive, Unit “E”
San Marcos, CA 92069
Phone: (760) 740-0954
Fax: (760) 740-0956
Powerdyne Automotive Products, Inc
Powerdyne Automotive Products, Inc. features their 50-state-legal BD-11A supercharger, which operates at a safe 6 to 9 psi. The silent-drive cog-belt-driven BD-11A is self-contained, self-lubricating, and is available for all 5.0L 1986- 1993 Mustangs and all 1988-2005 V-8 light-duty trucks.
Also available is the company’s Silent Drive BD-600 model, which is designed for smaller-displacement V-6 and V-8 engines, as well as for use in applications where space is at a premium. Mod-motor Mustang and F-Series enthusiasts will be happy to learn that Powerdyne’s BD-11A and reverserotation BD-11AR are available in a number of applications for 1996-2005 cars and trucks.
Powerdyne also manufactures their gear-driven XB-1A and XB-1A-R models for high-boost, high-horsepower applications. These blowers feature helical-cut gears, are externally lubricated, and can safely operate at boost levels up to 18 psi. Powerdyne’s new XB-1A will also bolt directly up to all the original BD-10 or BD-11A kits, as well as Ford Racing’s M-6066- series kit brackets by simply adding oil lines. Listed below are Powerdyne’s Mustang applications.
1986-1993 Mustang 5.0L, 8 psi, BD-11A silent drive, p/n K10170-101 (satin), p/n K10170- 201 (polished), includes FMU
1986-1993 Mustang 5.0L, 9 psi, BD-11A silent drive, p/n K10171-101 (satin), p/n K-10171- 201 (polished), includes 190-lph in-tank electric fuel pump and computer chip
1986-1993 Mustang 5.0L, 9 psi, BD-11A silent drive, p/n K-10179-101 (satin), p/n K-10179- 201 (polished), requires fuel pump and computer upgrades
1993 5.0L SVT Mustang Cobra, 8 psi, BD-11A silent drive, p/n K-10193-101 (satin), p/n K- 10193-201 (polished), includes FMU
1993 5.0L SVT Mustang Cobra, 9 psi, BD-11A silent drive, p/n K-10172-101 (satin), p/n K- 10173-201 (polished), includes 190-lph electric in-tank pump, computer chip, and FMU
1986-1993 Mustang 5.0L, 9 psi, XB-1A gear drive, K-10173-102 (satin), p/n K-10173-201 (polished), 190-lph electric in-tank pump and computer chip
1986-1993 Mustang 5.0L, 12 psi, XB-1A gear drive, p/n K-10174-201 (satin), p/n K-10174- 202 (polished), includes 255-lph electric intank fuel pump, aftermarket ignition upgrade, and 8-rib pulley setup
1986-1993 Mustang 5.0L, 12 psi, XB-1A gear drive, p/n K-10175-102 (satin), p/n K- 10175-202 (polished), requires fuel pump and aftermarket ignition upgrades
1994-1995 Mustang 5.0L, 6 psi, BD-11A silent drive, p/n K-10177-101 (satin), p/n K-10177- 201 (polished), includes FMU
1994-1995 Mustang 5.0L, 9 psi, BD-11A silent drive, p/n K-10178-101 (satin), p/n K-10178- 201 (polished), includes 190-lph electric intank fuel pump and computer chip
1994-1995 Mustang 5.0L, 9 psi, BD-11A silent drive, p/n K-10176-101 (satin), p/n K-10176- 201 (polished), requires fuel pump and computer upgrades
1994-1995 Mustang 5.0L, 12 psi, XB-1A gear drive, p/n K-10180-102 (satin), p/n K- 10180-202 (polished), includes 255-lph electric in-tank fuel pump, aftermarket ignition, 8-rib supercharger pulley, and bypass valve
1994-1995 Mustang Cobra 5.0L, 6 psi, BD-11A silent drive, p/n K-10195-101 (satin), p/n K- 10195-201 (polished), includes FMU
1994-1995 Mustang Cobra 5.0L, 9 psi, BD-11A silent drive, p/n K-10186-101 (satin), p/n 10186-201 (polished), includes 190-lph electric in-tank fuel pump, computer chip, and FMU
1994-1995 Mustang 5.0L, 9 psi, XB-1A gear drive, p/n K-10178-102 (satin), p/n K-10178- 202 (polished), includes 190-lph electric intank fuel pump and computer chip
1996-1997 Mustang 4.6L, 8 psi, BD-600 silent drive, p/n K-10190-101 (satin), p/n K- 10190-201 (polished), includes 190-lph electric in-tank fuel pump
1998 Mustang 4.6L, 8 psi, BD-600 silent drive, p/n K10194-101 (satin), p/n K-10194-201 (polished), includes 200-lph in-line fuel pump
2000-2001 Mustang 4.6L, 8 psi, BD-11R silent drive, p/n K-10196-101 (satin), p/n K- 10196-201 (polished), includes 36-lb/hr fuel injectors, 255-lph in-tank electric fuel pump, and custom-tuned computer chip
2001 Mustang Cobra 4.6L, 7 psi, XB-1A gear drive, p/n K-10197-101 (satin), p/n K-10197- 202 (polished), includes 255-lph electric intank pump, FMU, computer chip, 38-lb/hr fuel injectors
2001 Mustang Cobra 4.6L, 7 psi, XB-1R gear drive, p/n K-10197-101 (satin), p/n K-10197- 201 (polished), includes 36-lb/hr fuel injectors, 255-lph electric in-tank fuel pump, and custom-tuned computer chip
2005 Mustang 4.6L 3-valve, 6 psi, BD-11A silent drive, part numbers pending 4.6L/5.4L 3-valve trucks, part numbers pending
Powerdyne Automotive Products, Inc
A division of Wheeler Racing
104-C East Avenue K-4
Lancaster, CA 93535
Phone: (661) 723-2800
Fax: (661) 723-2802
Vortech Engineering’s famed V-1A trim gear-driven centrifugal supercharger has won more Best Engineered and Best Product awards at the SEMA (Specialty Equipment Market Association) Show than any other street blower manufacturer in attendance.
Vortech’s OE-type approach to system development is centered on the philosophy of safe boost design. This ensures the best blend of overall performance and reliability. Vortech superchargers produce more horsepower at a lower boost level than you might expect because of superior compressor efficiency and system configuration.
The original V-1A design has evolved into a total of 15 different trim types, or models, featuring different boost ranges:
V-1A-Trim, STD clockwise rotation.
V-1 S-Trim, STD/HD available clockwise or counter-clockwise rotation
V-1 SC-Trim, STD/HD clockwise rotation.
V-1 T-Trim, HD available clockwise or counterclockwise rotation.
V-2 SQ E-Trim, STD, available clockwise or counter-clockwise rotation.
V-2 SQ S-Trim, STD, available clockwise or counter-clockwise rotation
V-2 SQ SC-Trim, TD, available clockwise or counter-clockwise rotation.
V-4 J-Trim, HD, clockwise rotation.
V-4 XX-Trim, HD, available clockwise rotation.
V-4 Z-Trim, HD, available clockwise rotation.
V-5 G-Trim, STD/HD, available clockwise or counter-clockwise rotation.
V-7 YS-Trim, HD, clockwise rotation. This supercharger is also known as the Renegade, as it is used to compete on the NMRA and Fun Ford Weekend Series events
V-9 F-Trim, STD, available clockwise or counterclockwise rotation.
V-9 G-Trim, STD, available clockwise or counterclockwise rotation.
The key to Vortech Engineering’s overwhelming success is probably the fact that the company conducts a rigorous R&D program that includes street, trackside, and chassis and engine dyno testing. Heck, Vortech even has its own blower dyno!
Vortech also manufactures a complete line of After Coolers and Charge Coolers, which unlike intercoolers, are mounted in-between the supercharger and the throttle body. These units are reputed to drop the intake charge temperature by 40 to 60 percent!
Not surprisingly, the company offers kits for both street and strip. They are:
1999-2004 4.6L 2V GT H.O. with after-cooler, CARB E.O.# D-213-17
1996-1998 4.6L 2V GT H.O. with after-cooler, CARB E.O.# D-213-17
1986-1993 5.0L V-8 H.O. with after-cooler, CARB E.O.# D-213-17
1994-1998 3.8L V-6 Mustang, CARB E.O.# D213-17
1986-1993 5.0L Renegade Racing, non-certified
1994-1995 5.0L SVT Mustang Cobra, CARB E.O.# D-213-17
1993 5.0L Cobra with after-cooler, CARB E.O.# D-213-17
1999-2003 4.6L 4V SVT Mustang Cobra, CARB E.O.# D-213-17
2005 4.6L 3-valve Mustang GT, Reverse Rotation, CARB E.O. Pending.
Vortech Engineering, LLC
1650 Pacific Avenue
Channel Islands, CA 93022-9901
Phone: (805) 247-0226
Fax: (805) 247-0669
.010-inch overbore Ross forged-aluminum flat-top pistons (approximate compression ratio of 9.1:1), along with a set of wide bearing Chevy-journal Eagle H-beam forged-steel connecting rods featuring 7 ⁄16- inch ARP rod bolts. The engine features a Competition Cams mechanical roller cam (grind #31-000-9) that’s tolerable for the street, yet features a wide enough lobe center (112-degrees, 243-degrees intake duration at 0.050, 247 degrees exhaust duration at 0.050) to be able to breathe and work in conjunction with the Paxton supercharger. The valvetrain also includes Comp Cams flat-tappet roller lifters, 7.025- inch Comp Cams pushrods, Comp Cams valvesprings, Ferrea stainless-steel 1.94/1.60-inch intake and exhaust valves, and a set of Comp Cams 1.6:1-ratio roller rocker arms for 0.556 inches of valve lift.
The buildup also included a 650-cfm Holley 4-barrel carburetor and a set of Doug’s Headers Tri-Y headers. Since the Shelby was being converted over to a 4- speed, it needed a McLeod bell housing, a Centerforce lightweight billet-aluminum flywheel, and a Dual Friction clutch.
BUILDING A PAXTON-SUPERCHARGED 289 FORD “HI-PO” SMALL-BLOCK VINTAGE RACE ENGINE
The rumble is unmistakably Shelby – that whine is unmistakably Paxton! There’s nothing sweeter than the melodious whine and throaty rumble of a Paxton-supercharged 289 Ford small-block engine. That’s exactly how nightclub owner Fred Piluso felt after researching the history on his latest purchase, a black- and -gold 1966 Shelby GT- 350-H, serial number SFM 1653.
“The car was originally an automatic transmission car, and (according to the Shelby World Registry) it was updated sometime in the early 1970s with a Paxton supercharger. The registry also reveals the fact that the car was extensively drag raced in the central Ohio area!”
However, by the time Piluso purchased SFM 1653, the blower was long gone, and so were the original 289 Hi-Po heads. The correct serial number Shelby aluminum factory intake manifold was still there, but the old “rent-a-racer” had the wrong Holley carburetor. To add insult to injury, just about everything else inside the engine compartment that was indicative of a genuine Shelby GT-350-H was also missing.
“The car was a real mess. Instead of the Hi-Po heads, it had a set of 2-barrel 302 heads. We ran a leak-down test on the old engine and discovered that the compression numbers were all over the chart,” said Craig Conley of Paradise Paxton. “The installation of a supercharger on an engine like this would have been a disaster!”
Prior to installing a new Paxton SN-60 outer case equipped with up-to-date SN- 2000 internal workings, Piluso wisely elected to have Craig Conley and the Paradise Paxton crew completely rebuild and blueprint the Shelby’s 289 Hi-Po engine.
Conley continued, “Our objective was to build basically a good running blueprinted Paxton-supercharged 289 street engine capable of safely producing approximately around 375 horsepower on Supreme Unleaded pump gasoline. We wanted this engine to be able to compete in either open track events or at the drags. And, we also wanted to keep things as original as possible (at least externally) so that the car could be shown at any Mustang or Shelbyrelated concourse.
“What we wanted to do here was maximize the Paxton’s true performance potential. We did that through the cam and by performing a little bit of headwork while basically blueprinting the motor. Fortunately for us, the original 306-hp K-Code 289 HiPo block had never been rebuilt, and it was in excellent condition. All we had to do was come up with a set of 289 Hi-Po heads!”
When it came to the internal components for the engine, Conley selected the very best. That included ordering a set of 010-inch overbore Ross forged-aluminum flat-top pistons (approximate compression ratio of 9.1:1), along with a set of wide bearing Chevy-journal Eagle H-beam forged-steel connecting rods featuring 7 ⁄16- inch ARP rod bolts. The engine features a Competition Cams mechanical roller cam (grind #31-000-9) that’s tolerable for the street, yet features a wide enough lobe center (112-degrees, 243-degrees intake duration at 0.050, 247 degrees exhaust duration at 0.050) to be able to breathe and work in conjunction with the Paxton supercharger. The valvetrain also includes Comp Cams flat-tappet roller lifters, 7.025- inch Comp Cams pushrods, Comp Cams valvesprings, Ferrea stainless-steel 1.94/1.60-inch intake and exhaust valves, and a set of Comp Cams 1.6:1-ratio roller rocker arms for 0.556 inches of valve lift.
The buildup also included a 650-cfm Holley 4-barrel carburetor and a set of Doug’s Headers Tri-Y headers. Since the Shelby was being converted over to a 4- speed, it needed a McLeod bell housing, a Centerforce lightweight billet-aluminum flywheel, and a Dual Friction clutch.
Engine Block and Rotating Assembly
“When building a supercharged engine such as this, you want to maximize the thickness of the cylinder walls to maintain the overall integrity of the block and get maximum durability out of the engine. So, less cubic inches are better.”
Since Piluso’s K-Code 289 Hi-Po engine block had never been rebuilt, a 0.010-inch cleanup bore with a deck plate was all that was necessary. In the process, the crew at Paradise Paxton also stress-relieved and de-burred the block, and had it hot tanked and sonic cleaned. Then the block was line honed and decked to square it up to the center of the crank.
Next, the 289 Hi-Po crank was ground to 0.010 inch on the mains and 0.020 inch on the rod journals. In the process, the crank was Magnafluxed and de-burred, and the oil holes were chamfered. With all of the machine work done, the re-awakened 289 Hi-Po was externally balanced with a 28-ounce balancer.
Upon assembly, the torque specs on the mains will be set at 85 ft-lbs, working from the center main out.
“We basically set the main bearing clearance to racing specifications (0.0025- 0.0030 inch), since this engine is going to be run pretty hard. Rod journal clearances were set at around 0.0025 to 0.0026 inch, with a side-to-side clearance of 0.016 to 0.019 inch.
“Because this is a supercharged engine, the piston ring gap on the Childs and Albert chrome-moly piston rings was left a little loose, at 0.020 and 0.025 inch. Piston-to-wall clearance was also loosely set following Ross recommended clearance of 0.005 to 0.007 inch. Upon assembly, the connecting rod bolts were final-torqued to 70 ft-lbs.
“Again, being that this was a supercharged engine, deck height was set a little low as well (0.007 inch), giving us an acceptable piston-to-head clearance using the Fel-Pro ‘blue’ head gasket.
“One of the things that we did was install a Boss 302 windage tray and a Melling Performance standard volume oil pump. The engine runs 20W-40W Royal Purple Racing oil through a K&N High Performance Gold oil filter and original Shelby GT-350 T-oil pan.”
Cylinder Head Preparation
“We also did quite a bit of work to the Hi-Po 289 heads. After completely disassembling them, they were Magnafluxed and completely de-burred. Then we sent them over to Greg Grosset at Total Performance where he performed a 3-angle valve job and installed a new set of bronze liners.
“When we got the heads back, we performed what you would call a ‘supercharged porting job,’ which favors the exhaust side of the head. That included opening up the bowl on the exhaust valve. We also achieved a nice, short turn radius on the exhaust port, and opened the exhaust port up to its maximum limit, using the Fel-Pro gasket as a guide.
“We also cleaned up the bowl in the intake port, and once again matched the size of the intake port to the Fel-Pro gasket. Combustion chamber volume wound up being a total of 57 cc.
“We didn’t want to kill too much of the bottom-end torque and performance with the supercharged engine by going to too low of a compression. A factory Hi-Po 289 is 10:1 compression stock. With the supercharger, 9:1 compression is ideal. But since Hawaii has such great (dense) air and the car will be running high octane fuel, the final compression ratio turned out to be a calculated 9.932:1!”
Induction System and Supercharger
Since this is a resto-rod application, installation of the Paradise Paxton SN-60- SN 2000 6-psi supercharger was basically textbook. However, some things were doneto the 650-cfm Holley carburetor and Shelby factory 4V intake that bear mentioning.
“First we port-matched the intake ports on the manifold to match those on the 289 Hi-Po cylinder heads,” said Conley. “Then we installed a 6.5-lb power valve inside the Holley, along with installing a number-73 Jet in the primary fuel block and a number-88 jet in the secondary fuel block. We also installed a set of solid nitrophyl fuel floats to prevent the floats from collapsing under full boost conditions.”
When it came to the Shelby’s ignition system, Conley and company upgraded the factory Ford dual-point distributor with a Pertronix Igniter electronic setup set at 16-degrees initial timing, and a total of 34- to 36-degrees total advance.
INSTALLING PAXTON NOVI 1000 ON A 4.6L MUSTANG GT
The Novi 1000 is Paxton’s entrylevel gear-driven street supercharger package. However, that’s not to imply that the 50-state-legal Paxton Novi 1000 lacks the same “umph” of its bigger brothers, the Novi 2000 and the racebred Novi 3000. What that means is that the Novi 1000 was designed to appeal to performance enthusiasts who want the power of a centrifugal supercharger in a compact package – and that’s the Novi 1000 in spades!
The Novi 1000 features a wide boost range that enables it to be used on either 4 or 6-cylinder inline engines, as well as small-displacement V-6 and V-8 engines. That means at approximately 281 ci, a bone-stock version of Ford’s 4.6L twovalve engine isthe perfect candidate.
The 4.6-liter Mustang requires a reverse-rotation bower. Due to the close proximity of the related engine systems components on the 4.6L SOHC Ford modular V-8 engine and its relatively large dimensions, it became necessary for Paxton engineers to invert the supercharger. The 500-hp Novi 1000 is mounted to a sturdy two-piece, billet-aluminum cradle mounting bracket. Of course, that doesn’t affect the performance any, it just makes everything fit like factory.
Aside from the trick cradle-style supercharger mounting bracket, this particular kit also includes a set of castaluminum air discharge tubes, a set of 30 lb/hr fuel injectors, a programmed computer chip, a K&N lifetime conical air filter, a Paxton air bypass, and a Paxton anti-surge valve. The kit comes with an assortment of flex-hose elbows and air ducting, an eight-rib replacement serpentine accessory drive belt, all the necessary nuts and bolts, and above all, a fully detailed 30-page installation book.
What kind of performance numbers can your average Mustang enthusiast expect (that is, if there is such a person) with a Novi 1000 kit? On the Paxton dyno, this Rio Red 2001 Mustang GT convertible produced a best of 220.4 hp at 5,250 rpm and 252.5 ft-lbs of torque at 4,250 rpm in naturally aspirated trim.
After the installation of the reverse rotation Paxton Novi 1000, the horsepower increased to a best of 389.7 hp at 5,750 rpm and 375.4 ft-lbs at 4,750 rpm. That’s roughly a 77 to 78 percent increase in maximum horsepower, with a corresponding 49 percent increase in peak torque!
Paxton also offers this kit with an after-cooler, which is capable of raising the horsepower quotient from the stock 260 hp to 436 hp, with a gain of 120 ftlbs of torque. The after-cooler kit is CARB certified, too.
However, there is one fly in the ointment that may scare away certain would-be Novi 1000 installers whose late-model Mustang is their only source of transportation. You either have to get a custom computer chip burned, or send your computer to Paxton for upgrades, depending on your model of Mustang. This will probably mean at least a little bit of downtime.
Other than that, Paxton Automotive’s Novi 1000 supercharger kit is fairly straightforward. Of course, you’ll need an assortment of SAE and metric hand tools (mostly metric), along with a 3 ⁄8-inch x 18 NPT pipe tap, a floor jack (or better yet, a lift), a set of jack stands, and, of course, a supply of buckets or catch cans to collect and reuse that expensive coolant. Paxton Automotive Products also recommends obtaining a Helms Publications 2001 Mustang Shop Manual for those in doubt.
Now follow along with us as a Paxton technician performs his magic on this 2001 Mustang GT convertible.
BUILDING AN AF-FORD-ABLE 408-CI RENEGADE WINDSOR V-8
The proof is in the dyno numbers. Many dream about building an affordable supercharged small-block Ford V-8, but more than likely, very few actually go out and do it for fear that it will: A) Be prohibitively expensive and require a ton of exotic and costly high-performance aftermarket parts or B) once the job’s done, the darn thing won’t even be close to being streetable.
Yeah, well, dig this. What would you say if we told you that you could build a storming 408-ci Ford “smallblock” (ah, hem!) that’ll produce gobs of horsepower, can be driven on the street, and will cost in the neighborhood of 10 to 12K? Have we got your attention?
“An engine like this should be capable of producing between 450 and 475 streetable horsepower naturally aspirated,” said Dennis Hilliard, from Tehachapi, California’s Central Coast Motorsports (CCM). “And, once coupled up to a Vortech V-7YSi-Trim Renegade supercharger, this same combination will produce approximately 700to 750 safe horsepower with around 650 to 700 ft lbs of torque!”
And what kind of a car would you put something like that in? Any car you want, really. Seriously though, one of the hottest classes at the Fun Ford Weekend Series of drag racing events is their True Street category.
“In order to successfully compete in this class, you can run any combination of engine just as long as it’s in a fully licensed, street-legal car, competing on any size DOT drag radial tire you can fit underneath the fender well,” says Fun Ford Weekend Technical Inspector George Klass.
Dennis Hilliard was quick to agree, “When installed in the right car (preferably a lightweight Mustang LX), an engine like that should put you solidly in the high 9s at over 140 mph!
“What I would recommend is that you use across-the-counter parts to keep the cost at a respectable minimum. Once you get that combination dialed in, you can start pushing the envelope with custom cylinder head porting, larger-size fuel injectors, an exotic intake, and things like that. But for the time being, I would suggest that you maintain a conservative approach!” Hilliard definitely had our attention, but we still needed a little more convincing.
“With this kind of engine, I would suggest a later model Ford 351W engine block, a set of Ford Racing’s new Canfield-produced M-6049-Z304 aluminum cylinder heads, a Crane Cams roller cam and valvetrain, and a Probe Industries 4340 forged-steel stroker crank and engine kit.”
By now, we’re quite certain that you’re thinking, yeah, but what would one of these thumpers cost to build? “There’s nothing trick about this engine. Any experienced mechanic can duplicate what we’re about to do here. And all of the parts are available through CCM. To duplicate this engine in long-block form, complete with fully outfitted FRT Z-304 heads and Probe Industries 408-ci stroker kit, you’re looking at a cost of over $5,000. Of course, that’s without the Vortech V-7YSi-Trim Renegade supercharger package, which would probably run you another $4,500!”
Probe Industries 408-ci Stroker Kit
As previously mentioned, the Probe Industries 408 stroker kit features a 4340 forged-steel, cross-drilled crank with a 4-inch stroke and a 4.30- inch bore. Since this engine will be supercharged, our builder recommended a set of standard-size 3-inch chamfered main bearings manufactured by a quality manufacturer like Childs & Albert over an OE-type main bearing.
Quality bearings will have superior lubricating properties, and their softer bearing surfaces are more capable of withstanding the brutal pounding delivered by a supercharged engine. A set of 4340 forged-steel 6.2-inch Eagle H-beam connecting rods and a set of 28-oz SRP forged-aluminum pistons ride on the stroker crank. This entire engine assembly comes fully balanced by West Valley Engine Balancing.
Selecting a Suitable 351W Engine Block
We selected a new old stock (NOS) ’85 Ford 351W engine block that CCM had in stock.
“Any 351W engine block will do,” said Dennis. “However, since this engine will feature a Crane roller cam, you will also need to order a set of Crane’s 302/351W roller lifters. On the other hand, you may want to use the factory 351W roller cam block and roller lifter assembly, manufactured from 1994 to 1996, although the likelihood of finding one of those these days is kind of rare.”
As far as machining the actual block, the block was sent out to be decked by CCM, and its cylinders were bored and honed (0.025-inch over bore with a 0.005-inch finish hone) to achieve an overall bore increase of 0.030 inches. Due to the superior clamping force of the ARP main studs, the main webs of the block were also line honed to maintain concentricity.
Other modifications included short filling our 351W with Moroso Block Filler to strengthen and stabilize the bottom portion of the cylinder wall, without incurring any unnecessary heating problems. The front oil passage galleys were also drilled and tapped using NPT oil galley plugs.
With some stroker kits, providing sufficient thrust-side crank clearance on the bottom end is a must. Initial mockup of the Probe Industries stroker crank did, however, reveal a few minor problem areas. CCM engine builder Paul Williams noted that, “We discovered that the rear flange on the crankshaft rubbed against the recess area on the block. This necessitated setting the block up in a line boring machine, taking a cutting tool, and clearancing the recess about 0.0060 inch.
“After mocking up the number-one rod and piston assembly, we also discovered that the oil pump mounting boss needed to be ground slightly to clear the number-one counterweight on the crankshaft.”
With 700 to 750 hp on tap, does this engine need a girdle?
“Although many people prefer to use some type of engine girdle in applications like this, there’s really no need since the 351W has plenty of ‘beef’ in the bottom end of the block,” said Hilliard.
When it comes to providing adequate lubrication, you’re definitely going to want to run a windage tray of some type.
“We’re probably going to use one of FRT’s M-6687-A351 units, along with an FRT M-6675-F3511 5-quart oil pan and Engine Tech Oil Pump, and a Ford Power Parts 351W steel billet oil pump driveshaft.”
Selecting the Ideal Roller Camshaft
As previously mentioned, CCM selected a Crane Power Max hydraulic roller cam for this buildup. Cam characteristics feature 222 degrees duration and 0.552 inch max valve lift on the intake side, and 230 degrees duration and 0.574 inch max valve lift on the exhaust. “This cam should make excellent power all the way up to 6,500 rpm,” said Hilliard. “It looks like we have a lobe separation of approximately 112 degrees (meaning more exhaust overlap, which is necessary for a healthy breathing supercharged engine), which makes the Crane Power Max an ideal blower camshaft.”
At this juncture, it should also be noted that Crane provides two dowel pins with this camshaft. The longer dowel pin is to be used on 1973 to 1979 351W engines, while the shorter dowel pin is to be used in 1980 and newer 351W engine blocks because of a different timing cover and face of the latermodel Windsor blocks.
Ford Racing’s Z-304 Cylinder Heads & Valvetrain Components
Ford Racing Technologies M-6049- Z304 heads are manufactured from A356 T-6-aluminum alloy and represent the very latest street/competition cylinder head technology. Weighing in at just 27 lbs apiece, these heads feature high-flow 204-cc intake ports, 85-cc exhaust ports, and 64-cc combustion chambers. Sold bare and ready for final assembly, the suggested valve size is 2.02 inches on the intake side and 1.60 inches on the exhaust. You should also use manganese-bronze valve guides and stainless-steel hardened seats.
The Z head also uses 3 ⁄8-inch screw-in rocker-arm studs with laser-cut pushrod guide plates. They can accept either tapered-seal or gasket-style 14-mm (we chose Denso Iridium) spark plugs, and feature not one, but two pair of exhaust manifold mounting holes drilled into the exhaust side of the head, allowing you to run numerous header combinations.
Airflow numbers are quite impressive. The intake flows a full 277.3 cfm at 0.550 inch of valve lift, and the exhaust checks in at 218.12 at 0.550 inch, making these heads heavy breathers to say the least.
When it came to selecting the proper valvetrain hardware, CCM lined up some fairly impressive equipment including a set of Manley 2.02-inch and 1.60-inch stainless-steel intake and exhaust valves, along with a set of Crane Cams 1.6:1 roller-rocker arms and dual valvesprings. Finally, a set of lightweight Ground Pounder sheetmetal aluminum valve covers was selected to protect all the goodies!
Extrude Honing our 408 Stroker’s GT40/Cobra Intake System
Since we wanted to maximize airflow and keep cost down, we selected Ford Racing 351W GT40 cast-aluminum EFI lower intake manifolds and Cobra upper intake plenums. Recently, an aerospace industry-derived process known as “abrasive flow machining” has been applied to automotive induction and exhaust systems with tremendous success. Extrude Hone AFM is the industry leader in this field, and we’ve witnessed dramatic improvements in 5.0L and 5.8L induction systems after a trip to Extrude Hone.
We trucked our GT40/Cobra intake system over to Extrude Hone where technician Eddie Melendez bolted the system onto the company’s Super Flow 600 computerized airflow bench to establish a baseline. While the GT40 inherently flowed better than a stock 351W EFI intake system, we needed as much airflow improvement as we could get.
“Ideally, we’re going to need to get at least 30 percent more cfm out of this system in order to realize this engine’s true performance potential,” replied Dennis Hilliard. As it turned out, we wouldn’t be disappointed!
“Basically the amount of material we removed through the Extrude Hone abrasive flow machining process was approximately 1 to 1.5 mm per port,” exclaimed Extrude Hone president Ed Melendez.
“Obviously, more material was removed in areas where there was greater restriction and resistance. Special emphasis was placed on intake ports one and five, and they were equalized to match the remaining ports.”
After a couple of hot laps on the Extrude Hone abrasive flow machine, technician Eddie Melendez strapped our intake back on to his flow bench, and documented an average of 39 percent overall flow gain.
Last, but certainly not least, we selected one of Ground Pounder Performance Products’ adjustable venturi, 65- to 75-mm billet-aluminum throttle bodies anodized in black.
The Vortech V-7YSi-Trim Supercharger
The oil-fed Vortech V-7YSi-Trim gear-driven centrifugal supercharger is capable of producing up to 20 psi using an 8-rib, 3-inch Renegade pulley (2.85- inch and 3.15-inch under-drive and over-drive pulleys are also available).
This blower kit features twin-aluminum supercharger mounting plates for increased rigidity and a 4-inch idler pulley with beefy mounting flanges. This new bracket assembly will also accept an optional second idler pulley on the belt tensioner side, should the customer choose to run a dual idler pulley system.
This unit features a 4-inch-diameter air inlet, with a 3.64-inch inducer on the supercharger. Maximum efficient impeller speed on this unit is 60,000 rpm with a 65,000-rpm redline. Max boost for the Vortech V-7YSi-Trim is 29 psi, and its adiabatic efficiency is 74 percent. For this buildup, we also selected a set of Vortech Engineering anodized fuel rails.
For this build the folks at CCM chose a set of MSD 65-lb/hr fuel injectors, an MSD Flying Magnet Crank Trigger ignition setup (which gets its name because of the four magnets that are imbedded into the surface of the aluminum crank trigger wheel attached to the harmonic balancer), an MSD Pro Billet 351W distributor, along with optional bronze distributor drive gear (an absolute must-have with a roller cam), and a Fuel Air Spark Technologies (F.A.S.T.) Electronic Engine Management System equipped with the company’s C-Comp software. Other components include an Edelbrock highflow aluminum reverse-rotation 5.0L/5.8L water pump, a Ford Racing heavy-duty clutch and pressure plate, and a 24-oz billet flywheel.
That pretty much covers our 351Wbased, supercharged 408-ci stroker’s equipment inventory. Noted engine builder Paul Williams conducted actual engine assembly in two phases. The 351W was mocked-up to trial fit all the components and check critical engine clearances. The engine was then final assembled and delivered to the dyno shop.
It’s Time to Make Some Thunder!
On the dyno at Westech Performance Group, dyno tech Tom Habrzyk immediately began preparing our 408 for a trip to the “polygraph room,” a humorous term the staff at Westech use to describe their Super Flow 901- equipped dyno cell. First, Habrzyk filled the crankcase of our 351 with 5 quarts of Royal Purple 10W-30 racing oil, and used a drill motor to run up the oil pressure, which pegged in at 68 lbs.
The next order of business was checking out the 408’s fuel and ignition systems, followed by actually installing the engine on the dyno. In the process, Habrzyk fashioned all the necessary supercharger air ducting using various lengths of 3-1 ⁄2-inch aluminum tubing joined together with hose clamps and neoprene rubber hoses. Prior to firing the engine for the first time, the final step included installing a fresh set of Denso Iridium spark plugs.
Engine break-in was done for approximately 45 minutes on Union 76 92-octane pump gas at 20 degrees advance. Then Habrzyk and fellow dynamometer technician Steve Brule winged the big-inch Windsor engine for the first time in naturally aspirated trim. After a few fuel/air curve adjustments, here’s what they achieved:
Max Engine Torque: 559.9 ft-lbs at 3,500 rpm
Max Horsepower: 455 hp at 4,900 rpm
Naturally aspirated, the 408 would make a very nice street engine, but our dyno technicians wondered out loud just how stout this combination might be with a more aggressive cam profile.
Unfortunately, we did experience one minor problem early on in the testing. With as much oil pressure as this engine has, a single oil breather was insufficient, and we were experiencing blow by. Oil baffling and adding an additional breather is the most obvious cure to the problem. However, since dyno time is golden time, the addition of an Accu-Sump oil reservoir evacuation system immediately took care of the problem.
After giving the engine a thorough check out, Brule and Habrzyk slapped on a new 8-rib serpentine belt, reinstalled all the maze of ducting to the blower, poured in some 100-octane Rocker brand unleaded race gas, reset the timing at 20 degrees advance, and we were ready to rumble. In supercharged configuration, this is what we achieved on the first pull:
Max Engine Torque: 755.1 ft-lbs at 4,300 rpm
Max Horsepower: 707 hp at 5,300 rpm
Now we were getting somewhere! These numbers were produced at 12.3 lbs of boost. Obviously, the torque and horsepower increases over the naturally aspirated figures are quite significant. But we knew that there was still a little more room to play, so after about a halfhour cool down, Brule and Habrzyk conducted a third and final pull. Changes included increasing the timing to 22 degrees of advance and replacing the 100 octane with some 114-octane leaded fuel.
Max Engine Torque: 775.6 ft-lbs at 4,300 rpm
Max Horsepower: 753 hp at 5,400 rpm
We all realized that since the last pull was conducted using leaded racing fuel at 15.5 psi, you technically couldn’t use this combination on the street. But on the racetrack, it’s an entirely different story.
“This is a really good street engine,” says Habrzyk. “Intake runner length obviously dictates low-end torque, and low-end torque on this engine is fabulous for the simple reason that with the GT40/Cobra intake, we have a lot of runner length. However, the problem with that is that the engine will not rev up to 7,000 rpm. Obviously, some of that has to do with the camshaft. And some of it has to do with the intake manifold. If you were to change out the upper intake plenum with something like a composite air box, or switch to a short runner EFI intake like the Edelbrock Victor Jr. throttle body intake manifold, it would kill some of the bottom-end torque, which with this engine you can sacrifice. After all, too much torque will simply blow off the tires. More importantly, by going to the air box, you would actually increase engine RPM and peak horsepower considerably, perhaps up to 40 to 50 hp, and that’s what you’re going to need.”
How about the amount of boost produced by the Vortech V-7YSi-Trim Renegade supercharger?
“We were well above 12-lbs boost at higher RPM,” says Tom. “One problem that we ran into at higher RPM is that with the single idler pulley setup, we experienced some blower belt slippage. Installing a second idler tensioner pulley would obviously cure that!”
So there you have it – a 753-hp Vortech-supercharged 408 Windsor stroker for a price of around $10,000 to $12,000, minus engine builders and machine shop charges. This is a really great engine for any serious street racer, entrylevel bracket racer, or Fun Ford Weekend Series True Street competitor to drop into a late-model Mustang, Thunderbird, or Cougar. Of course, with that much torque on tap, you’re going to have to do a little chassis work to keep the darned thing from twisting up like a pretzel!
PARADISE PAXTON TWIN SN-60 SUPERCHARGER INSTALLATION
When we looked at this setup, all we could think of was the old racer’s adage, “If one is good, then two is better!” Of course, Craig Conley, the owner of Paradise Paxton, offered a more plausible explanation. He insisted that the TwoStage and Straight Blow-Through twin supercharger kits were designed to deliver between 10 and 14 lbs of safe boost using the readily available pulley system on the engine.
This is nothing but good news for Ford enthusiasts who already have a Paxton supercharger setup on their car, as well as for those who are planning to install one in the very near future.
“Obviously, since you’re going to be running a lot of boost, you need a healthy stock (8.5:1) compression engine to begin with. We highly recommend that you run a set of forged-aluminum pistons, and a blower cam with a lobe separation of between 110 and 112 degrees in order to maximize the blower’s potential. We also recommend that you either O-ring the heads or run a high-grade material competition-style head gasket, along with a set of head studs.”
Installing the two-stage Paxton twin supercharger setup is as simple as installing one of Paradise Paxton’s beefy 5 ⁄8-inch thick, 6061 T-6-aluminum mounting plates, and SN-60-cased blowers. If you already have a Paxton SN-60 blower, you can use it with the twin kit, which also works with the factory 4-barrel carburetor and intake.
“We’ve made it possible to order either our two-stage or straight blowthrough kits with either a pair of internally updated Paxton SN-60 blowers or with the polished SN-2000-type cases, and we also offer an optional polished or anodized billet-aluminum blower plate with either kit!”
Installing one of Paradise Paxton’s straight blow-through twin supercharger systems on your vintage Shelby or Mustang isn’t any more complicated than installing the two-stage kit. However, if you don’t already have one, you will need to pick up a factory Ford inline dual-quad intake, or a top-quality reproduction like a Blue Thunder, an Edelbrock, or Holley/Weiand, along with a pair of 600-cfm Holley carbs.
“We recommend a set of 600-cfm, vacuum-secondary Holley carburetors for street applications, or a set of 600- to 660-cfm Holley center squirters for race setups. That’s one blower per carburetor! With the single-stage setup, we roughly estimate that you can double the amount of horsepower. And with the dual quad setup, we estimate an additional 10 to 15 percent gain.”
“We designed both of these setups so that they would be minimal hassle to install onto a stock 260-302 engine, although you will have to make a couple of minor modifications.”
You’ll have to relocate the battery to the trunk since you’ll need that area to mount the air cleaner. With certain aftermarket water pumps, you may have to trim approximately 1 inch off the heater hose neck (don’t worry, there’s still plenty of material left) to accommodate one of the mounting studs. Other than that, everything else is strictly bolt-on!
Of course, seeing is believing, so follow along with us as Craig Conley and his crew at Paradise Paxton install one of their twin SN-60 straight blow through setups on this dual quad-equipped 1966 Mustang coupe.
Written by Bob McClurg and Posted with Permission of CarTechBooks