Stabilizing the Ford FE Upper Valve Train

Shaft Rocker arm systems…

Stabilizing the Ford FE upper valve train

For over 20 years, the Ford FE-series engines were a key component in Ford’s engine family.  The FE engine family was Ford’s initial “big blocks” and a key Ford weapon to the automaker “Horsepower wars” of the 1960s and early 1970s.


Appearing in the late 1950s, the initial offering was a modest 332 cubic inch engine, which supplemented the standard Y-block engines.  It shared the Y-block design, where the block extended below the crankshaft, but had a significant number of improvements.  The 332 was used in Ford and Edsel cars, but was quickly enlarged in 1958 to 352 cubic inches for police car use, and named the “Interceptor.”  By the 1960 model year, the 352 Interceptor had become the base engine for Ford sedans, the Thunderbird and for Edsels.

By 1961, the horsepower race between the “Big 3” automakers had begun, and the 390 appeared as a high performance option with a performance grind cam, solid lifters, 10.5:1 compression and a cast “header”-style exhaust manifold – good for 375 horsepower.  Interestingly, Ford included a 3×2 aluminum intake in the trunk, which could be installed by the dealer, good for over 25 more horsepower.  This became the Ford big block option for several years in the Ford and Mercury lines – with various compression ratios and 2- or 4-barrel carburetors.

The 406 cubic inch version came in 1962 and was phased out for the iconic 427 by 1964.  The 406 introduced the cross-bolt main caps, which was retained in the 427-inch engines.  The 427 was developed as a true high performance engine – highly successful in NASCAR and drag racing, although the 406 could easily be considered as a high performance engine, since it powered a number of drag racing and circle track cars in lightweight Ford Galaxies.  The factory Ford “Thunderbolt” team showcased the powerful 427 side oiler engines in ultra-lightweight mid-size Fairlanes, and the engine “made its bones” both in Galaxies in NASCAR, as well as the Fairlanes and Galaxies on the drag strip.  They also powered Cobras and the Ford GTs in road racing – with 427 powered Ford GT Mark IIs sweeping the top three spots at LeMans in 1966.

The 428 came in 1966, with a more production-friendly design, and it found its mark both as a street performance engine, as well as a race package, with the popular Cobra Jet (CJ) and Super Cobra Jet (SCJ) offering some serious power with a variety of cam, carburetor and compression ratio options.

The FE-series powerplants, particularly the 390 cubic inch and larger versions, provided street performance enthusiasts, as well as racers, a very strong bottom end, and heads which were well known for having extremely good air flow characteristics.  These factors, along with the factory’s medium- and high-riser intakes (for the 427) has kept the Ford big block performance popular long after they were supplanted by the 429 to 460 inch engines in the 1969 model year.

That popularity has been supported by plenty of FE-specific products from the factory and performance aftermarket.  These products, which benefit from high tech, computer driven design and manufacturing techniques, continue to drive the FE engine marketplace, delivering more power and reliability.


Keeping the FE mystique alive  

Even 40 years after Ford stopped production, the FE engines continue to perform very well on the drag strips, plus the growing interest in the nostalgia race cars – particularly in drag racing – has kept the FE-powered reproduction and restored race cars popular.  Street performance cars, particularly the 428 CJ- and SCJ-powered Mustangs, and to a lesser extent, the Ford Torino, Mercury Cyclone and Cougar, have added to the FE popularity.

The upper valve train area has been particularly active for the FE-series powerplants, as improvements in technologies, materials and manufacturing processes have continued to improve performance.

One of the leading companies in the upper valve train field is PRW Industries of Perris, Calif.  The company has recently made advances in its PQX shaft rocker arm systems for the FE engine family, reflecting improvements in both designs and manufacturing.  These have delivered increases in performance, consistency and valve train stability.

Shaft-style rocker arm assemblies have grown in popularity over the years for street performance enthusiasts and racers (where class rules will allow them).  The biggest advantage of the shaft system over the OEM-style pedestal mount rocker arm is rock-solid stability.  As cam lifts and durations increase, along with higher spring pressures, the rigidity and consistency of the shaft system can deliver higher engine speed potentials, better air flow and more power.  Even in a modest street performance application, the shaft system provides not only the potential of more power (depending on the cam profile, spring rates and the air flow characteristics of the head, intake and exhaust system), but improved durability.  And, the shaft systems provide better valve train stability and durability compared to pedestal-mount rocker arms with billet aluminum girdles.

Like all PRW products, the PQX shaft rocker system design begins with a CAD (computer aided design) program, which is matched with premium quality materials to assure repeatable, precision manufacturing.  In PRW’s manufacturing facilities, the CAD design is applied in the computer-aided manufacturing (CAM) centers to assure design tolerances are held to high standards, with repeated quality checks for all components throughout the manufacturing and assembly process.  Immediately upon arrival in the PRW shipping department, the parts are again quality checked against the design tolerances.

The Ford FE-series shaft style rocker arm assembly

PRW’s PQX Ford FE-series shaft style rocker arm assemblies cover from the 352 cu. in. engine introduced in 1958 through 428 CJ and SCJ engines last made in 1978.

The assemblies are available two rocker arm styles — extruded aluminum made from SAE 2024 alloy (p/n 3339032) or the newest style –cast stainless steel alloy rockers (p/n 3239022), made from premium grade SAE 17-4ph alloy. Both have a 1.75 ratios, and are very strong and highly durable.

Materials aside, there are many similarities between the PQX aluminum and cast stainless rocker assemblies.

Both assemblies are compatible with low-, medium-rise intakes or high-port factory heads, as well as many performance aftermarket heads, which makes these rocker arm assemblies excellent for high performance street applications, and for racing (again, where sanctioning body rules allow shaft rocker arm assemblies).  Both feature silicone-bronze bushing inserts for smooth, low friction operation, and use ball-style valve lash adjusters.

The roller tips are made from long-lasting Cr40 steel, which can withstand high rpms, high open spring pressures and the stress of high lift, long duration cam grinds.  Both rocker arm are profiled on the underside to provide additional clearance for high performance valve springs.

Both kits use the same centerless-ground chromoly steel shafts that are bored for internal oiling of the rockers.  Both systems feature CNC-machined double pedestal anodized billet aluminum end supports, billet aluminum intermediate support mounts and spacers, which ensures the entire structure is well-supported and rigid – critical to keep the valve timing geometry correct.  The shaft supports are attached to the heads with PRW’s AXS® aerospace-grade rolled thread studs and 12-point nuts.

Both kits also include shims to fine-tune the installation to the head and pushrods and two pushrod length checking tools.  Pushrods are not included in the kits, but PRW offers a wide range of its PowerPlus™ pushrods to assure the correct length for the application.  Additionally, PRW has partnered with Manton® Pushrods to market their highly regarded pushrods, which offer an extremely wide selection of pushrod types and tips for mild to ultra-high performance applications.

In addition to the shaft rockers and pushrods for the FE-series engines, PRW markets CMD Assembly Lubricant, as well as PRW’s Vibra-Titethreadlockers to ensure the proper assembly and longevity of the entire system.


PRW is focused upon providing the racer or street enthusiast best quality valve train product – including the needed support products – for a long-lasting, high performance end result, all at an affordable price.

Mike Purugganan Aug 10, 2018 Blog 15 Comments Read More

Finding a Solution to GM LS-1 and LS-3 Rocker Arm Problems

The arrival of the all-new General Motors LS-series engine in the late-1990s brought with it a new learning curve for the automotive enthusiast, as well as to the automotive engine service industry.

Identical only in a few areas, including the cylinder bore spacing, to the iconic small block Chevrolet that had dominated the North American automotive landscape for nearly a half century, the LS-series platform brought new directions to the company’s power plant offerings.

The engines were built to tighter tolerances and utilized many new features designed to generate greater efficiencies – delivering greater power from less displacement.  A portion of this came from the all new head design that discarded the original valve layout of the small block Chevy (middle exhaust valves next to each other) and the continuation of the reverse cooling pattern introduced on the small block LT-1 in 1992 (where cool coolant is introduced at the top of the engine); both of which improved performance efficiency.

Additionally, General Motors made changes to the valve train, including the rocker arm design.  The OEM rockers went from the familiar stamped steel design to a cast steel material, which was smaller and lighter.  This allowed for higher engine speeds, while reducing the moving mass in the valve train.

While these were improvements in efficiency, there are a shortcomings.   The trunion assembly, around which the rocker arms pivot, became subject to failure – even in everyday usage.  The trunions were made from powdered metal, and the needle bearings were “uncaptured” – meaning there was no cage to keep the bearings in place.   Additionally, the rocker arms pivot across a limited arc and the uncaptured bearings which were under the greatest stress were unable to rotate to distribute the wear like a caged needle bearing assembly.  Eventually, the strain would begin to push the bearing pack out of position.  This would lead the bearings falling out of the rocker arm assembly, and fall into the oil on the top of the head, which would lead to bearings getting into the engine’s oiling system – sometimes with catastrophic results.

The OEM rockers on the LS-1 and LS-3 heads, while lightweight, are not exceptionally stiff, and aren’t designed for sustained high RPMs, or higher performance cams and stronger valve springs.

Overcoming shortfalls in OEM design

As the LS-series engines have aged, the OEM rockers’ weak trunion design has become a problem, as the uncaptured needle bearings escaped from the rocker arms, and got into the oil galleys.  Additionally, the OEM design’s inability to allow the needle bearings to rotate around the pivot of the trunion will cause the needle bearings to wear unevenly – potentially leading to failure.

PRW Industries has developed a solution to this problem with the development of replacement trunion assemblies (p/n 1213462).  They feature a new design trunion made from a high quality alloy steel, which delivers high strength and long life.  The new design also features fully caged (secured) needle bearings, which are held in place by C-clips, preventing the needle bearings from pushing out of the trunion assembly.  The caged bearings in the trunion allow the rocker to have a full 360° rotation, allowing the bearings to rotate around the trunion’s pivot shaft, spreading the wear more evenly.


However, the replacement trunions take time to install – a problem for a service shop which desires to reduce the time to complete needed repairs.

Again, PRW has responded with a solution.  Recognizing the need for timely service turn arounds, and enthusiast convenience, the solution has been to marry its trunion repair kits with new, improved replacement rocker arms which are much stronger than the stock arms.

The new PRW PQX LS Alloy Rocker Arms feature a tough, cast steel alloy material which makes them ideal as an OEM replacement, as well as ideal for a mild street performance application.  The combination of the new stronger trunions, coupled with the light weight, but stronger, stock 1.7 ratio rocker arms deliver a much longer service life.  They answer the needs of automotive service centers for rocker arms which install in normal time, are affordable and have longevity for the customer.

For the performance enthusiast who wants a reasonably priced, durable rocker arm which can accept valve springs with slightly higher pressures, plus a mild street performance cam, these rockers are an ideal solution.

The PRW PQX rocker arms are available for LS1/LS2/LS6, 5.7L-6.0L engines (1997 – up) with Cathedral ports (p/n 0634617), and LS3/L92 6.0L-6.2L engines (2007 – up) with offset intake, Square Port heads (p/n 0636417).  Both part numbers include 8mm, Grade 12.9 Hex Socket Fasteners in the kit.

Affordable, durable and easy to install, the PRW PQX LS Alloy Steel Drop-In Rocker Arms provide a trouble-free solution to a problem for automotive service centers and the LS enthusiast community.

Mike Purugganan May 17, 2018 Blog 1 Comment Read More

Taming High Performance Diesel Torque

The diesel engine has become a solid fixture of the light truck market for several decades, and have become a target of a slice of the high performance aftermarket.  For a variety of reasons, the desire to extract more horsepower and torque from these basically utilitarian powerplants have captured a sizeable segment of light truck enthusiasts that helped me on moving with the help also of .

A leader in the light truck diesel market has been the Dodge, now RAM, brand of Fiat-Chrysler America (FCA).

Beginning in 1989, Dodge began to install the B-series Cummins 5.9-liter inline, turbocharged 6-cylinder engine with a modest (by today’s standards) 160 horsepower in the brand’s 2500- and 3500-series pickups.  The target audience were buyers in the agricultural, construction and other industries where the diesel’s low end torque (400 ft-lb) matched well with the heavy loads encountered. The trucks were equipped with manual transmissions or the rugged A-727 Chrysler automatic transmission.

Ford and General Motors quickly responded by offering their V-8 diesel engines, designed for their medium-duty commercial trucks into the Chevrolet/GMC and Ford pickup lineups following the Dodge/Cummins introduction.  The awareness of the advantages of the diesel powerplants soon attracted the recreational vehicle market – particularly the owners of large, bumper hitch and fifth-wheel travel trailers.  It also began to create interest in the truck enthusiast marketplace.

However, it was Dodge’s Cummins power plant which seemed to attract the most interest.  The excellent torque of the inline-6 seemed to fill the needs of the various markets which were attracted to the diesels, and a solid marketplace was born.

As years passed, the 5.9-liter Cummins engine became intercooled, and an inline injector pump replaced the initial rotary pump, and 4-valve heads replaced the original 2-valve heads as the marketplace was asking for more power and torque.  These changes pushed the power to 350 horsepower, and the torque to 650 ft-lb.

In model year 2008, the engine was expanded to the current 6.7-liters, but the power and torque remained the same as the 5.9 of the previous year – 350 horsepower and 650 ft-lb of torque.  For several years, the horsepower remained constant at 350 HP, but the torque began to climb in 2011 when it reached the 800 ft-lb mark. For model year 2018, the RAM 2500 Cummins diesel package is rated at 370 HP and 800 ft-lb of torque, while the RAM 3500 offers a class-leading 930 ft-lb of torque, and 370 HP.

All of the improvements from the Cummins factory engine package over the years saw the Dodge and RAM models set the standard in diesel performance, and the diesel light truck market has responded – with 2 million-plus Cummins-powered Dodge and RAM trucks sold since 1989.

Power and torque enhancing products from the performance aftermarket have blossomed over the years, and the diesels have taken to the track.  Diesel drag racing has seen significant growth, as well as classes for diesel-powered 4-wheel drive truck pulling.  This also includes street performance enthusiasts, plus those wanting added towing and hauling capabilities for commercial or recreational use.

A problem…

However, there is a weak spot in the chain.  It is between the crankshaft and the transmission, particularly true with automatic transmission-equipped trucks.  As with gasoline engines, diesel engines which get the performance boosted significantly above the stock factory ratings, the strain placed on the drivetrain can potentially cause significant damage.  This is particularly true in competition environments, but can also be a problem in heavy duty use.

As power and torque of the Cummins engine increased, FCA recently turned to heavy-duty Aisin 6-speed automatic transmission to handle the ultra-high torque loads north of 900 ft-lb found in the 2017 and 2018 3500-series, but the factory flexplates are approaching their limits.

When racers and enthusiasts “turn up the wick” on the Cummins B-series engines, they are exposing themselves to the risk of flexplate failures, and the possibility of vehicle damage, and personal injury to themselves and/or bystanders.

The guilty party is high levels of torque, which can lead to the stock flexplate beginning to show hairline cracks, which can lead to serious cracking or distortion.  Cracks and/or distortion seriously weakens the structure, which can shear at the flexplate’s mount to the crankshaft output flange, causing loss of power to the transmission, and the engine to freewheel to high RPM levels.  It may also cause shearing at the flexplate mounts to the torque converter.  Additionally, excessive twisting may cause failure of the welds on starter ring gear.  The failure of the flexplate has caused failed parts to break through the transmission’s converter housing, and send parts into the truck body or out of the truck itself.

Racing sanctioning bodies, recognizing the dangers, are specifying the flexplates used in diesel competition be certified to meet the tough, competition diesel-specific SFI 29.3 specification.  For lower horsepower/torque engines used in competition (street stock or mildly modified) or heavy hauling or towing, the standard SFI 29.1 is recommended.

A solution

One of the leading suppliers of diesel performance flexplates is PRW Industries (Perris, Calif.).   Recognizing the need for a performance flexplate solution, the company has engineered a Cummins flexplate from the ground up, using computer-aided design (CAD) to assure the highest design tolerances.  The PQX® Signature Series flexplates are made from a single piece of high-strength billet steel.  The design include the starter gear machined into the billet flywheel, which eliminates the potential for a starter gear weld failure.

Each raw steel billet plate is placed into a computer-controlled machining center, and using the CAD created program, is manufactured to precise tolerances.  Each flexplate is then precision balanced, and given a black oxide coating.  These flexplates are available for the 1994-2007 5.9 liter engine, and the 2008-current 6.7 liter engine.  (See specifications below)

Following the initial SFI certification, to assure the racing community of a manufacturer’s continuing compliance, the SFI periodically purchases a flexplate at random, and retest to the tough certification process to assure the flexplate meets or exceeds the minimum standards.

PRW also offers diesel flexplates in the company’s PQX® Platinum Series line that meet the SFI 29.1 specification, which are a significant improvement over the OEM flexplates.  They are available for both Cummins engines.  Additionally, they are available for Ford Powerstroke engines – the 1989 – 2006 7.3 liter engine with the E4OD or 4R100 transmissions, and the 2003 – 2007 6.0 and 6.4 liter engines equipped with the 5R110 transmission, On other advertisements, if you’re looking for reputable online casino gaming, check this out!

The PRW PQX® Platium Series flexplates have a very durable 4 mm steel centerplate which provides a solid foundation for these new designs. The starter ring gears are precision welded to meet SFI specifications, using a robotic, cold-welding process.  (See specifications below)


PQX® SFI-Rated Signature Series Steel Diesel Flexplates (Competition) for Cummins B-series engines

Application Balance Teeth Weight Part Number
DODGE 5.9L Cummins 1994-07, One Piece Billet Steel, Meets SFI Diesel Spec 29.3, Black Oxide Internal 152 11.50 lb 1835921
DODGE/RAM 6.7L Cummins 2007-Up, One Piece Billet Steel, Meets SFI Diesel Spec 29.3, Black Oxide Internal 152 12.25 lb 1840821

PQX® SFI-Rated Platinum Series Diesel Steel Flexplates for B-series Cummins, Ford Powerstroke


Application Balance Teeth Weight Part Number
DODGE 5.9L Cummins 1994-07 (Prior years may require aftermarket transmission spacer) Meets SFI Spec 29.1 Internal 152 9.75 lb 1835910
DODGE/RAM 6.7L Cummins 2007-Up, Meets SFI Spec 29.1 Internal 152 9.70 lb 1840810
FORD 6.0L/6.4L Powerstroke Diesel, 2003-2007 363ci for 5R110 Transmission, Meets SFI Spec 29.1 External 141 9.39 lb 1836311
FORD 7.3L Powerstroke Diesel, 1989-2006 445ci for E4OD or 4R100 Transmissions, Meets SFI Spec 29.1 External 155 9.53 lb 1844511


PRW feels the line of SFI 29.1 and 29.3 spec flexplates for high performance/competition diesels fills a very much needed safety niche in the high performance diesel market.  These flexplates, properly used and installed, will protect personal safety and property.

Mike Purugganan May 03, 2018 Blog 0 Comment Read More

Didn’t go to the SEMA show this year? Here’s a shortcut!

Whether you’re a weekend wrenchturner or a Daytona 500 racecar driver, you know you can always pick up valuable information about everything from rpms to racing at the SEMA show this year. But for those that can’t make it or need more information, the internet becomes our digest of information.

That’s even more evident in today’s world, where social media platforms like Facebook, YouTube and Twitter brings people with a common interest even closer together. From the racetrack to the garage, we’re constantly sharing our results and working hand-in-hand with others to achieve a common goal or purpose.

In fact, it’s social media that enables companies like PRW Industries to publish its own news, information, tips, tricks, strategies — and even warnings — for anyone interested in high performance auto racing parts and accessories. And it does this almost instantaneously!

And just like you can count on us to stay ahead of the competition when it comes to the latest and greatest products for performance parts, you can bet we’re working our way toward the forefront when it comes to imparting knowledge to our fans. That’s why we’d like to take this opportunity to invite you to Like PRW on Facebook, follow us on Twitter, and subscribe to our YouTube channel.

In addition to the blog post that you’re reading right now, we offer three other excellent ways to stay abreast of new developments in racing and what PRW is doing to make our offerings safer, more efficient and, of course, faster.

Join the thousands of our customers who feel the same way you do about racing. Just click on the boldface items below to sign up:


PRW on Facebook:

This is where we post exciting photos and updates from races we attend, cars we love, and sponsors we support. We also answer customer’s questions about the products we sell. This is also where you’ll find announcements about special offers and sales and contests, and it’s where we share company news and more.



PRW YouTube Channel:

Subscribe to view the videos we create in-house — many focusing on the proper installation and use of the high-performance auto racing parts and accessories we manufacture and/or sell, and more.


PRW on Twitter:

Here, we plan on publishing alert-style news related to items from which you can instantly benefit — say a killer deal on something we sell — or maybe an update from a racing event while that event is still going on.

Feel free to pick and choose from among these social media offerings, or sign up for all three. It’s just another way to like, follow or watch us and become apart of something better, meaner, and faster!

admin Oct 31, 2017 Blog, SEMA Show, SOCIAL MEDIA 0 Comment Read More