Ford big-block engines enjoy a wealth of available cylinder heads designed for performance use. It is common knowledge that Ford engineers struggled a great deal when it came to port sizing. Ports were typically too large or too small, with not much in between, when Ford was at its performance peak. Large ports worked exceedingly well at high RPM on the race track, where they worked best and flowed the most air. When these large ports found their way into street engines, low- and mid-range torque suffered. Performance buffs have learned through the years that they can work with off-the-shelf parts to achieve improved levels of low- and mid-range torque on the street. Sometimes you have to shelve the big-port, closed-chamber heads to improve street performance. This is a common issue with the 351C/351M/400M small-blocks. It is also true with the FE- and 385-series bigblocks.
This Tech Tip is From the Full Book, HIGH-PERFORMANCE FORD ENGINE PARTS INTERCHANGE. For a comprehensive guide on this entire subject you can visit this link:
LEARN MORE ABOUT THIS BOOK HERE
SHARE THIS ARTICLE: Please feel free to share this post on Facebook / Twitter / Google+ or any automotive Forums or blogs you read. You can use the social sharing buttons to the left, or copy and paste the website link: https://www.diyford.com/cylinder-heads-valvetrain-interchange-big-block-fords/
Proper cylinder-head, valvetrain, and camshaft selection is everything when it comes to building a performance engine. These components have the most direct effect on output. The objective is to help you select the right combination for best results.
With such a wide array of heads available, this section’s information cannot be taken lightly! The addition of great new aftermarket heads for older Ford V-8s adds fuel to the fire, and learning the pros and cons of all these designs is important. This section will introduce you to the available options, and make your decisions easier.
The FE-series big-blocks enjoy a large selection of cylinder head choices. Some of these castings are rare and relatively expensive. Other heads work as suitable substitutes for the exotic pieces. You don’t always have to have a set of 427 Medium Risers or 428 Cobra Jets to infuse performance into your FE-series big-block.
It is important to remember that most of the FE engines had the same valve sizes throughout. For example, the 332/352/360/361/390 and 410 all had 2.02-inch intake and 1.55-inch exhaust valves. Differences lie mainly in combustion-chamber size (compression ratio) and port size. Port size doesn’t vary much among these engines. For example, the 390 High Performance head has the same valve and port sizes as the early 427 High Performance head. This means you don’t have to pay 427 prices in your quest for power. Huge differences exist when you step up to the 427 High-Riser and Tunnel-Port heads. If you’re building a strong street FE engine, then you don’t need anything beyond a Low-Riser or Medium-Riser head. And because the Low-Riser head isn’t much different than the 390 High Performance or many of the standard heads, you have a huge playing field with which to work.
Although you are not likely to ever see them, those first 332/352 heads had machined combustion chambers. Ford’s bean counters swiftly concluded machined combustion chambers were costly and abandoned them for as-cast chambers. Machined chambers make little difference in performance. Those first 1958-vintage heads set the standard for FE heads to follow. Aside from combustionchamber size, standard FE heads didn’t change much. Valve sizes (2.02/1.55 inches) remained the same for standard FE heads, as did port size. This makes interchangeability a snap, and with very few exceptions.
You need to pay close attention to cylinder-head application as it applies to vehicle type and performance purpose. If you’re going to pump the compression up high, then use heads with thicker castings at the mating surface.
You also have to watch combustionchamber size and type because it’s important. Mismatching a piston and combustion chamber creates problems you don’t need when it’s time to assemble the engine. For example, not all 427 heads bolt onto other FE engines. Because the 427 has huge 4.23-inch cylinder bores, Ford was able to step up valve sizes. All other FE engines had smaller bores, creating valve clearance problems with some 427 heads with Tunnel-Port and High-Riser units. This sometimes mandates the machining of valve reliefs at the top of the cylinder bores.
In searching for FE heads, keep in mind the variations that exist at the exhaust ports. The only problem this may present is compatibility with exhaust manifolds and headers. There are three basic approaches to FE and FT cylinder heads: 16-bolt (four bolts at each exhaust port), 14-bolt (four bolts outer and three bolts inner) and 8-bolt (two bolts each port). The 16-bolt exhaust-port heads were common to Mustang, Cougar, Fairlane, and Comet engine compartments due to limited space. More common is the 14-bolt head. The 8-bolt heads are common to various FE applications. A different 8-bolt design is common to the FT head. Unless you are serious about low-RPM, high-torque use, the use of the FT head is discouraged. The FT head is a truck head designed for low-RPM, high-torque use.
When the words Low-, Medium-, and High-Riser are used for the 427 heads, this is not a description of the head itself, but the intake manifold that goes with the head. The best all-around cylinder head is the Medium-Riser, which affords a good balance of street and strip performance. The High-Riser head and manifold were designed for all-out racing. Examine the head’s tall ports, and you quickly understand why it’s a race head. The high-riser head does its best work for a 427 at 6,500 to 7,800 rpm. The low-riser is the first-generation 427 head and manifold combination, which affords excellent street and weekend strip performance. The Medium-Riser is obviously a step up from the Low-Riser. Low- Riser parts are generally less expensive.
Cylinder-head selection for 385-series engines is simple compared to the Feseries big-blocks. Throughout the lifetime of the 429/460 engine family, cylinderhead design didn’t change much, except for combustion-chamber size. As compression ratios dropped in the 1970s and 1980s, chamber size increased accordingly. There were three basic 429/460 heads used of which you should be aware. They are in the table and images to follow.
The most common 429/460 head is the standard head found on non-Cobra Jet/Police Interceptor 429/260 engines. This head yields adequate compression for most performance applications. Port size keeps low- and mid-range torque acceptable for street use. Certainly rare is the D0AE Cobra Jet head of 1970–1971. Because Ford didn’t make a lot of these to begin with, they are not easy to find today. However, the 1972–1974 429/460 Police Interceptor head is a good substitute for the Cobra Jet head because it offers improved breathing with a slightly larger chamber (reduced compression). It also has hardened valve seats for use with unleaded fuels. It is a great low-dollar alternative to the Cobra Jet and Ford Motorsport SVO heads. The thing to remember when you’re shopping for heads is that bigger is not always better when it comes to port size. Larger ports lose low-end torque. Smaller ports bring excellent lowend torque for good streetability.
Due to its very purpose as a NASCAR-born racing engine, the Boss 429 has many variables in the area of cylinder heads and valvetrain. The detuned street version of this engine yielded two basic cylinder-head castings: C9AE-A, and D0AE-AA. There are quite a number of race head castings that were conceived for different purposes. One Boss 429 expert I spoke with is convinced there are roughly 50 different castings floating around out there. Some of the differences are subtle. Others are dramatic. Here I focus on street applications, with some discussion on the racing side.
These vintage engines’ valve-operating systems are typical of the era when they were manufactured, and are reliable enough to be effective in bone-stock form. However, there are options available. Which one would be best for your engine? There are several factors to consider, and all of them are presented here.
The FE- and FT-series Ford big-blocks were all (except the 427 SOHC) equipped with shaft-mounted rocker arms. The main differences lie in mechanical versus hydraulic lifters (which affects the rocker-arm ratio and adjustability), and pushrod length. Four rocker-arm shaft types were used during the production life of the FE and FT from 1958–1976. The original B8AZ-A rocker-arm shaft was for mechanical lifter engines only; look for the shaft with eight oil holes along the bottom. The B8AZ-D rockerarm shaft was designed for hydraulic lifter engines; look for the shaft with 16 oil holes. A revised rocker-arm shaft, C3AZ-A, which is very similar to the
B8AZ-A shaft, had adjustable rocker arms and two additional oil holes. The C5AZ-A shaft was also a mechanical lifter shaft designed for use on the 427 Medium- Riser and Tunnel-Port engines.
Two rocker arms were used throughout the production life of the FE and FT engines. The B8AZ-B was an adjustable rocker arm designed for use with mechanical lifters. It called for the use of a “ball and cup” pushrod compatible with the B8A-B adjustable rocker-arm. The cup end mates with the rocker arm adjustment screw, while the ball end seats in the mechanical lifter.
The B8AZ-C rocker arm was a nonadjustable piece designed for use with hydraulic lifters only. This called for a “ball and ball” pushrod where either end could be seated in the rocker arm. You can use the B8AZ-A rocker arm with hydraulic lifters, which eliminates the need for guesswork when it comes to varying pushrod lengths. You can adjust the valve lash with ease by simply tightening the adjustment screw until appropriate valve lash is achieved. The B8AZ-A rocker arm also affords more valve lift thanks to its 1.76:1 ratio.
Valve lash with hydraulic lifters and non-adjustable rocker arms is adjusted by controlling pushrod length. You can take up excessive valve lash by opting for a longer pushrod as necessary. Caution is mandatory whenever you increase pushrod length to compensate for excessive valve lash. Five basic pushrod types were available from Ford for hydraulic lifter FE engines: C0AE-J (9.59 inches), C8AZ-A (9.59 inches), C4TZ-B (9.62 inches), C4TZ-D (9.56 inches), and C3SZ-A (9.77 inches). Valve lash is adjusted through the use of 0.060-inch undersize and oversize pushrods. If valve lash is excessive, add 0.060 inch to the pushrod length. If valve lash is too tight, opt for a 0.060-inch shorter pushrod. Always check valve lash with the engine hot and the lifters filled with oil.
Another important area to consider is lifter type. FE engines were originally equipped with three types of lifters: mechanical, shell, and hydraulic. It is important to properly match the correct lifter with a compatible pushrod. Check lifter height as well as pushrod length.
Always check static valve lash before firing the engine. There should be some clearance when the engine is cold and the lifters have bled down. Allow for this, then start the engine and allow it to reach operating temperature. Then check valve lash.
Valvespring selection is rooted in camshaft choice and expected RPM range. Always match your valvetrain to the type of camshaft selected. A radical camshaft calls for stiffer springs. Likewise, a milder cam calls for softer springs. Look to Crane, Crower, Competition Cams, and other camshaft grinders for the appropriate valvespring and retainer type for your application. Each of the camshaft companies offers roller camshaft conversion kits for FE-series engines, which improves performance and reliability.
While you’re thinking about rocker-arm shafts and rockers for the FE, keep in mind Ford produced four different rocker-arm shaft pedestals as well. Most of the FE engines used the C2AZ-6531-B pedestal. This is an aluminum pedestal, which can take the pounding of stock valvetrain components. Three other Ford pedestals for the FE are designed for high-performance use and must be selected carefully. The first of the high-performance pedestals is the C3AZ-A cast-iron piece, which is a bolt-in swap for the C2AZ-B aluminum pedestal. If you’re stepping up to a hotter valvetrain, opt for the C3AZ-A steel pedestal.
When Ford introduced the 427 High-Riser heads and induction system late in 1963, the C3AE-A cast-iron pedestal was born. This pedestal is High- Riser specific, due to the altered valve configuration. It should not be used on any other FE head. The difference in this pedestal is clear at 1.72-inches tall versus the standard pedestal’s 2.20 inches. It also measures 1.10-inches wide compared to the narrower 1.02-inch-wide C2AZ-B and C3AZ-A pedestals.
The C5AZ-A cast-iron pedestal is Medium-Riser- and Tunnel-Port-specific, which means it is not designed for any other FE head. This pedestal also measures 2.20 inches in height like the C3AE-A piece for the high riser. Rockerarm pedestal bolts vary in length for all pedestal types, depending on the pedestal—the taller the pedestal, the longer the bolt.
Changes were few in the 385-series valvetrain throughout its production life. Standard and Cobra Jet 429/460 heads had positive-stop, no-adjust rocker arm fulcrums. The standard and Cobra Jet 429s used the C8SZ-6564-A rocker arm. The 429 Super Cobra Jet for 1970–1971 had adjustable rocker arms (C9ZZ-6564-A) with mechanical lifters. This meant the 1970–1971 429 SCJ had adjustable rocker arm studs (C9ZZ- 6A527-A) instead of positive-stop, noadjust types found on the standard and CJ engines (D0OZ-6A527-A). Several pushrod types were available for the 429/460 engines, with their differences being rooted mostly in length.
Valvespring, retainer, and keeper selection depends upon the camshaft you have selected and operating range. Again, look to Crane, Comp Cams, Crower, and other camshaft grinders for the appropriate information.
Boss 429 engines were a world unto themselves in nearly every respect, including an exotic valvetrain. Intake valves were fitted with short, shaft-mounted, adjustable rocker arms (C9AZ-6564-C). Exhaust valves re ceived the long, shaftmounted, adjustable rocker arms (C9AZ- 6564-D). Pushrods for this engine were also distinctive. Intake pushrods were shorter (C9AZ-6565-A, 8.76 inches) than exhaust pushrods (C9AZ-6565-B, 10.88 inches), making it virtually impossible to position them in error.
The camshaft is the brain of the engine, as it determines the engine’s effective RPM range. Choosing the bestpossible camshaft depends on many factors, including vehicle weight, engine compression ratio, and desired RPM range. Decades of continuing research have resulted in much more effective cam profiles than were available when these Ford engines were new.
Today’s aftermarket offers the enthusiast a wealth of camshaft selections for the FE-series big-block. You can fit your 427 with an original-specification, mechanical-tappet camshaft for the thrilling chatter of 16 rocker arms and mind-bending performance. Depending upon the block you’ve selected, you can opt for a roller-tappet hydraulic camshaft to improve performance and high-RPM operation. Remember, the hydraulic lifter block can be fitted with a flat-tappet mechanical camshaft, and it can be fitted with a roller-tappet camshaft. However, the mechanical lifter block cannot be fitted with a hydraulic camshaft.
It is important to note that Ford engineered the FE and FT engines with three different camshaft types. Here is what you should remember: All FE engines, except the 427 Side-Oiler, used the same type of mechanical or hydraulic camshaft. If you are building a 427 Side- Oiler, you must specify this fact to the camshaft grinder because this camshaft has different journals than the rest of the FE engines. The 427 Side-Oiler camshaft has grooves at the number-2 and -4 journals, due to the Side-Oiler block design. The rest do not. The FT camshaft has wider journals, which is important to remember if you are using an FT block. If you have a 330/361/391 block, you need a custom-ground camshaft designed for the FT engine.
If your engine build includes installing a mechanical lifter camshaft in a hydraulic lifter FE block, don’t forget to plug the oil-gallery passages that lead to the lifters themselves. Mechanical lifters don’t need the oil flow through the two long oil galleries, which run the length of the block. This entails drilling and tapping for block-off plugs—an easy task for the seasoned engine builder.
The only other concern is the timing set. Regardless of your FE engine’s transmission, always specify steel timing gears at the minimum. Original-equipmentstyle nylon-coated timing gears, made this way for quieter operation, are strongly discouraged. A nylon-coated camshaft timing gear lasts for 100,000 miles. However, it does not stand up to high-performance use. Opt for a doubleroller timing set if your FE is expected to see a lot of severe-duty use. The general rule is: the more potent the camshaft, the more likely you should use the doubleroller timing set. Remember, early FE engines have the camshaft button that goes between the sprocket and the timing cover. Later on, the camshaft was retained with a cam plate.
Camshaft selection basics for the 385-series engines is straightforward. All 429 and 460 engines, with the exception of the 1970–1971 429 Super Cobra Jet, were equipped with hydraulic lifters and no-adjust rocker arms. The Super Cobra Jet had mechanical lifters with adjustable rocker arms. When building a 429/460, the choice is yours when it comes to camshaft selection. You can go with hydraulic or mechanical lifters. And you can go with roller tappets.
Originally, 429 Cobra Jet engines were fitted with the C9AZ-6250-A hydraulic flat-tappet camshaft. Super Cobra Jets got the D0AZ-6250-D mechanical lifter camshaft. If you’re shopping for a new-old-stock camshaft, look for a “BJB” stamping on the SCJ camshaft and “8J” on the hydraulic.
Camshaft selection for the 429/460 boils down to mission. Aftermarket companies such as Crane, Competition Cams, Crower, and Isky offer a wealth of camshaft systems for the 385-series bigblocks. I say “camshaft systems,” because selection should always be rooted in packaging—matched components designed to work well together. Valvespring selection should always hinge directly on camshaft profile and expected RPM range. A radical camshaft should receive stiffer valvesprings than a stocker, and so on.
As with the FE engines mentioned earlier, I suggest the use of a good roller or double-roller timing set for precision valve-timing events. The aftermarket offers many options for the performance buff.
Valve covers don’t have much influence on performance. However, they matter a great deal in terms of appearance and proper operation. FE engines were offered with an array of valve-cover types throughout their service life. Choices ranged from stamped steel to attractive cast aluminum.
In the beginning, in 1958, FE-series engines were fitted with rounded stampedsteel valve covers devoid of any breathers since crankcase ventilation took place elsewhere, primarily via the intake manifold. The oil-filler cap was positioned at the front of the intake manifold with a separate draft tube. Aside from stamped-steel valve covers with special names, such as “THUNDERBIRD” or “MERCURY,” there weren’t many variations early in the going. It wasn’t until 1963 that chromed versions of the rounded, non-vented FE steel cover became available with the launch of Ford’s Total Performance era.
Steel FE valve covers changed in 1965 with a new pent-roof design, which also incorporated an oil-filler cap and PCV-valve provision. There was also a pent-roof valve cover, first used in 1964, for the 427 devoid of oil-filler and PCVvalve provisions.
Cast-aluminum valve covers for the FE engine were many. It appears the “Cobra LeMans” and “Cobra Powered By Ford” were the first OEM cast-aluminum valve covers conceived for the FE engine. There are two versions of the “Cobra LeMans” valve cover that I’m aware of. Beginning in February 1969, Ford began using a cast-aluminum “428 Cobra Jet” valve cover that replaced the chromed stamped-steel “Power By Ford” previously used on the 428 Cobra Jet and 390 GT engines. There was also a cast 428 Cobra Jet valve cover devoid of “428 Cobra Jet” markings.
The 385-series 429/460-ci big-blocks were available with two basic valve-cover types: steel and cast. There was one castaluminum valve-cover type used on 429 Cobra Jet and Super Cobra Jet engines from 1970–1971.
Written by George Reid and Republished with Permission of CarTech Inc