Ford’s family of big-block engines encompasses a wide variety of cylinder heads and applications. Ford engineers stayed busy focusing on engineering changes that drive enthusiasts crazy. Most of these engineering changes are hard to see on the surface, but each had a purpose. Few of these changes have any effect on power. Port size variation is something having little, if any, effect because ports are generally too large or too small, depending upon which engine family you are addressing.
FE Series port sizing is befuddling because there’s very little difference in port size across the board unless you’re talking 427 cylinder heads. The 385 Series big-block employs four basic cylinder heads even though there are a number of casting/part number differences. The MEL was a low-revving luxury car engine. However, it achieved fame in powerboat cruising and racing. Despite both factors, Ford produced one basic cylinder head for the MEL with slight variations.
The real beauty of Ford big-block heads is easy identification and broad selection in each engine family.
A big plus for FE big-block buffs is a plethora of factory head castings, with the added bonus of OEM-style head castings from Blue Thunder, Robert Pond, Bear Block Motors, Survival Motorsports, and Edelbrock that give an FE build a stock demeanor without revealing what’s inside. These manufacturers offer more choices than ever and that means unprecedented power gains.
This Tech Tip is from the full book,
FORD BIG-BLOCK PARTS INTERCHANGE. For a comprehensive guide on this entire subject you can visit this link:
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/how-to-easily-identify-ford-big-block-cylinder-heads/
FE cylinder heads have 10 head bolt holes and 4 rocker arm pedestal attachment bolt points. Each end sports 3/8-inch threaded bolt holes for accessories. What makes the FE cylinder head odd is that it shares the valvecover with the intake manifold. That makes the FE head narrow compared to the 385 and MEL series heads. All valves are on a common plane of 13 degrees in relation to the block deck. Combustion chambers range in size from 58 to 88 cc, depending upon which head you’re thinking of.
Most FE cylinder heads have the smaller chambers at 58 to 74 cc. High-performance cylinder heads such as the 427’s traditionally have larger 77- to 88-cc chambers, with compression regulated by piston dome configuration. Exhaust port passages jut way out from the valvecovers as they do on a Pontiac or Oldsmobile cylinder head.
It is well known that massproduction FE cylinder heads don’t vary much across all castings. Port sizing across FE production history varies little despite dozens of part and casting numbers. For example, the GT High Performance cylinder head doesn’t have enough of a port/valve size difference to be worth its distinction. It is basically the same head found on Galaxies and pickup trucks with only minute variations.
If you’re searching for noticeable horsepower gains, the 427 Medium Riser/428 Cobra Jet head is your best option in a factory iron head. You will find that dyno room port and bowl work makes a significant difference in FE power. Boosting compression, while keeping available pump gas in mind, is the quickest way to FE power. Compression should never go beyond 10.0:1 unless you can come up with a suitable cam profile designed to control dynamic compression.
The 332/352/360/361/390 and 410 all have 2.020-inch intake and 1.550-inch exhaust valves. Differences lie mainly in combustion chamber and port dimensions, with combustion chamber sizing having a direct effect on compression ratio. Huge differences exist when you examine the 427 cylinder head grouping. For street and weekend racing you’re not going to need any more than the 427 Medium Riser casting. For all-out racing the 427 High Riser head is the best choice in a factory casting. The 427 Low Riser head isn’t really any different than most FE heads of the era.
What made those first FE 332/352 cylinder heads distinctive were their machined combustion chambers, which went away when Ford started looking at cost. This is when Ford went to “as-cast” FE chambers. FE cylinder heads didn’t change much after that. The beauty of the FE big-block head family is selection and interchangeability. The negative is the absence of choice. There’s just not much difference in FE cylinder head castings; the exceptions are the 427 Medium Riser, High Riser, and Tunnel Port heads along with the 428 Cobra Jet head (which is basically the 427 Low Riser).
You must also watch combustion chamber size and piston profile when you’re shopping cylinder heads. It is easy to mismatch and wind up with either too much compression or not enough, which leads to unnecessary expense. For example, not all 427 heads bolt onto all FE engine blocks. Because the 427 has huge 4.230-inch cylinder bores, Ford was able to step up the 427 to larger valves. If you’re going to bolt 427 heads on your 390 block, the 427’s valves may not clear the smaller diameter cylinder walls, especially if you’ve copped a set of Tunnel Port heads, which very few would ever consider bolting onto a 390 block. A competent machine shop may be able to machine valve reliefs in the block deck depending on your application. It is best to keep 427 heads on 427 blocks or face the complications of mixing them up.
In your search for FE cylinder heads, be mindful of exhaust port configurations. You must have compatible exhaust manifolds/headers. There are three basic exhaust configurations with FE/FT cylinder heads: 16-bolt (four bolt holes at each port), 14-bolt (four bolt holes outer and three bolt holes inner), and 8-bolt (two bolt holes at each port). The cylinder heads with 16 bolt holes are specific to the 428 Cobra Jet in the Mustang, Cougar, Fairlane, Cyclone, and Comet due to shock tower clearance issues. The 14–bolt-hole 390 GT head is more common. The 8-bolt FE heads are easily the most common cylinder head found in most Ford passenger cars and trucks.
All Low, Medium, and High Riser cylinder heads are 427 castings. The best all-around FE cylinder head is the 427 Medium-Riser. This head delivers a good balance of street and strip performance. The 427 High Riser head is a standalone casting engineered for racing only, even though some have applied it to street use. This casting is a high-RPM piece and of little value for the street due to its tall ports and smaller chambers (translated higher compression and the need for race gas). The High Riser head does its best work at high RPM, 6,500 to 7,800. The 427 Low Riser cylinder head isn’t much different than a 1961–1962 390 High Performance casting, and is priced accordingly. It is a good performance head and advanced for its time.
Because the MEL was developed as a large-displacement luxury car engine, cylinder heads didn’t evolve much because they didn’t need to. The MEL head isn’t your typical Ford head. In fact, there’s no other Ford cylinder head like it. It has a flat deck like a diesel cylinder head void of combustion chambers, which are at the top of each cylinder. Actually, combustion chambers, if you can call them that, were flat from 1958 to 1959. Where the MEL head varies is the pocketing of combustion chambers from roughly 1959-on in order to reduce compression and detonation (pinging) issues. Instead of a flat surface, these heads got small combustion chambers around the valves and spark plug.
This Tech Tip is from the full book,
FORD BIG-BLOCK PARTS INTERCHANGE. For a comprehensive guide on this entire subject you can visit this link:
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.cartechbooks.com/products/ford-big-block-parts-interchange-1/
This flat-deck head void of combustion chambers was designed that way, with the block deck cut at a 10-degree angle to the piston dome giving the top of the cylinder a wedge chamber instead of the cylinder head. Ford (and also Chevrolet with its 348/409-ci W Series big-block engines) did this as a means to compression control, although it didn’t work very well.
When you’re selecting pistons for your MEL project, it is crucial to keep cylinder head design in mind. Not all MEL heads have a flat deck surface at the valves and spark plug. Later heads have a small pocket chamber around the valves to reduce compression and change the dynamics of combustion. Piston dome size and shape determine compression in the MEL, as does cylinder head selection. This means you must be mindful of cylinder head type going in.
MEL cylinder head selection directly affects piston selection. If you get this wrong, you can wind up with too much compression or not enough. If you opt for a flat-top piston, expect to lose compression, especially if you’re using the later MEL head with the small chamber.
You will have to look to custom piston manufacturers, such as Wiseco and Egge, for your MEL project because pistons for these engines are not widely available. There’s simply not enough demand for them. Before these companies can make a piston for you, they must know what you have for cylinder heads. The MEL piston was originally designed to not only compress the air/fuel mix and transfer power, but to manipulate how air and fuel were compressed. Ford learned this through trial and error with at least three known cylinder head revisions intended to eliminate rough running and detonation.
As MEL cylinder head design changed, so did pistons, which further punctuates why you must pay close attention to piston and cylinder head selection as a package. Because the MEL was a challenging engine, there were ongoing changes in cylinder heads, pistons, and induction.
Another issue for early MEL engines was excessive compression and low-octane fuels primarily with export vehicles. Ford issued a Low-Octane Fuel Adapter Kit (PN I-502592) consisting of cylinder head gaskets and spacers, intake manifold gaskets and spacers, head bolts and dowels, and longer pushrods. According to Ford documentation at the time, the Low-Octane Fuel Adapter Kit took compression from 10.5:1 to 7.14:1 on the Mercury 383 and from 10.5:1 to 7.25:1 on the 430. The Edsel 410 undoubtedly had the same kit for compression reduction. Ford/Lincoln/Mercury service departments had the option of retarding ignition timing prior to this kit. However, retarding ignition timing hurt power and fuel consumption.
Cylinder head selection for the 385 Series 429/460 is straightforward compared to the FE. Throughout the lengthy production life of the 385 there were four basic cylinder head castings you should be concerned with. There is the standard 429/460 casting, Cobra Jet, Police Interceptor, and the Boss 429. The Boss 429 cylinder head with its hemispherical chambers requires no introduction. It is a standalone head and engine.
Here’s an E6TE truck head casting with Thermactor provision (arrow), which is plugged for non-Thermactor emissions use. These Thermactor heads have minimal exhaust port restriction.
Where the 429/460 wedge heads vary is in combustion chamber shape and size. In truth, the 429/460 cylinder head delivers excellent flow characteristics in all its forms. The most common 429/460 heads are the C8VE-A, C9VE-A, and D0VE-A, which are all basically the same cylinder head casting with 2.090/1.650-inch intake/exhaust valves and 2.180 x 1.870–inch intake ports and 1.990 x 1.300–inch exhaust ports. This is a head casting with 75- to 77-cc wedge chambers you can do port and bowl work on and wind up with significant flow improvement.
Another casting is the D2VE-A2A, which isn’t much different than the aforementioned heads, except for a larger open 100-cc chamber, which delivers poor quench and reduced compression. The D2VE-A2A head is more prone to detonation due to its huge open chamber. The D3VE-A, D3VE-A2A and higher are emissions heads with open chambers with poor quench. Although they have smaller chambers they’re a disappointment from a performance standpoint. Ford continued to cast the basic 460 head through the mid-1990s. When these engines were deleted from the option sheet in 1979, they continued in Ford F Series trucks and E Series vans. These head castings will show up as E7TE, E8TE, and so on, which are basically the D3VE-A casting with engineering revisions designed more for electronic fuel injection and reduced emissions.
The rarest 429/460 head is the 1970–1971 Cobra Jet casting, D0OE-R with 2.190/1.730-inch intake/exhaust valves, 2.510 x 2.110– inch intake, and 2.250 x 1.300–inch exhaust ports along with 71- to 75-cc chambers. Because the Cobra Jet head is rare and darned expensive you may opt for the 1972–1974 Police Interceptor castings with the same valve sizing as the Cobra Jet head, yet with smaller ports and 88- to 91-cc chambers. Police Interceptor head port sizes are 2.200 x 1.930– inch intake and 2.060 x 1.310–inch exhaust ports, which means better low- to mid-range torque. Exhaust scavenging is debatable with these heads, with virtually little or no gain.
The Police Interceptor heads have hardened exhaust valveseats for use with the unleaded fuels introduced at the time. There are three Police Interceptor castings, D2OE-AA. D2OE-AB, and D3AE-FA, all with 88- to 91-cc chambers. The Police Interceptor head is an alternative to the more expensive Cobra Jet head because it offers better low-end torque for street use.
Any way you look at the hemi-head Boss 429, it is not the same as a conventional 429/460. This engine was born for NASCAR competition. There are many variables when it comes to cylinder heads and what to do with them. The street Boss 429 is a detuned version of an all-out factory-born racing engine. There are two basic Boss 429 cylinder head castings: C9AE-A and D0AE-AA. There are also race and experimental cylinder head castings circulating out there. One Boss 429 expert states that he believes there are at least 50 different cylinder head castings out there. Some differences are subtle while others are more obvious.
Written by George Reid and republished with permission of CarTech Inc
LEARN MORE ABOUT THIS BOOK!
If you liked this article you will love the full book!