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-Tite™ threadlockers 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.