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Ford FE Stroker Build

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Guardian of the Galaxie 

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How Ford’s FE Engine Rose from the Ashes of Disaster to Become a Versatile Veteran

Ford’s FE engine has had a rich history that, today, is often overlooked or at least misunderstood. Many of us who have been around awhile have heard the term FE, but not a lot of people of today’s era know much about the engine family this is associated with. 

I had always heard about and seen some of the more popular FE engines such as the 390, 427 and 428 but never had a chance to dive into one. Several years ago, we had the opportunity to build a 390 FE for a customer’s 1962 Galaxie. With the 390 and a four-speed, the car was fun to drive and garnered a sort of nostalgic celebrity status from local fans, but the engine did smoke quite heavily at times and did consume quite a few quarts of oil and would foul several spark plugs on some very short trips around town.

The engine was supposedly rebuilt when my friend had purchased the car, but something was definitely wrong with this power plant. So, we took this opportunity to take the engine out so we could explore an FE engine. We’ll discuss the rebirth of this iconic engine after a brief history lesson.

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Uncertain Beginnings

The FE stands for “Ford Edsel” and was produced from 1958 to 1976. It’s still considered one of Ford’s most versatile platforms and continues to offer engine builders and their customers creative opportunities.

Where did the Edsel name come from? Yes, it’s most often known as the car that was noted as the biggest marketing disaster from Ford, but where did the name come from? Edsel was Henry and Clara Ford’s only son born in 1893 and named after one of Henry’s closest childhood friends, Edsel Ruddiman.

The streamliner that Edsel Ford and E.T. Gregoire built in 1934 doesn’t bear much resemblance to the vehicle ultimately built to honor Edsel’s memory.

Destined to take over the family business, Edsel became the secretary of Ford in 1915. He bought the first MG motorcar that was imported to the U.S and, having a passion for styling, in 1932, Edsel and Ford’s chief designer E.T. Gregorie built a speedster. It was aluminum, boat-tailed V-8 powered automobile that incorporated features that no other automobile had. Some of these features haveappeared on Ford vehicles throughout history.

In 1934, Gregorie built another speedster named the Model 40 with more styling and lower ground clearance. The Model 40 has since been restored and is on display in the museum at the Edsel and Eleanor Ford House.

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After becoming president of Ford, Edsel pushed to replace the Model T but Henry would not hear of it. However, due to declining car sales, Henry agreed to let Edsel introduce the Model A. Edsel helped design the body and introduced such features as four-wheel mechanical brakes and the slide-gear transmission. The Model A was a huge success with over 4 million in sales in four years of production.

Edsel went on to introduce the Mercury brand and was responsible for the production of the Lincoln Zephyr and Lincoln Continental. After a battle with stomach cancer, Edsel died in 1943 leaving a legacy to his four children.

However, in the early 1950s, Ford became publicly traded and was no longer owned by family members of Ford. Ford’s research team and found that, although the purpose of the Lincoln was to compete with the Cadillac, the public actually believed that Lincoln competed with Oldsmobile and Buick instead. So Ford Motor Company decided to upgrade the Lincoln Continental and introduce a new automobile to compete in the medium car. With an automobile code named “E” car for experimental, the car that was introduced became known as the “Edsel” in honor of Henry’s son.

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The car-buying public at the time was demanding innovation and technology, and Ford was sure that the Edsel would deliver. The new vehicle employed such innovations as “rolling dome” speedometer, warning lights for low-oil level, parking brake engaged, and engine overheat. It also incorporated Push-Button Teletouch transmission in the center of the steering wheel. Other features included self-adjusting brakes, seat belts, and childproof rear door locks.

However, the Edsel car production went down as one of history’s biggest marketing disasters. Thanks to pricing and styling concepts that the public just could not understand, Edsel came to an end on November 19, 1959. Total car sales were 116,000 less than expected with a company loss of $350 million. If you want to get an idea of the scope of the loss, that amount of money in today’s market would be well over  $2.8 billion

What wasn’t a failure was the engine that powered that car. The FE engine was designed to be a medium sized engine capable of producing more power than a small block with less weight than a big block for medium sized cars.

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The FE was considered a Y-block design because the block casting extended 3.625˝ below the centerline of the crankshaft, which was about an inch below the journals of the crankshaft. The Y-block design offered great support for the crankshaft. The crankshaft main journals are 2.749˝ and the connecting rod journals are 2.438˝. All of the FE blocks share the same bore spacing of 4.630˝ and a deck height of 10.17˝. These engines also used two different connecting rod lengths: 6.488˝ and 6.540˝.

The FE enginefamily includes ten different bores and four different strokes. They can be classified into two generations. Generation I was available from 1958 until 1966 and included the 330, 332, 352, 360, 361 and 390 cubic inch displacements. From 1966 until 1976, Generation II FEs had larger bores and strokes and included the 406, 410, 427 and 428 cubic inch displacements.

These engines were produced as two versions: the FE, which was intended for cars and FT, which was intended for use in buses and light trucks. The best way to differentiate between the two is to look for the motor mount bosses. If the motor mount bosses are on the side of the block, then the engine was designed for a car. If the motor mount bosses are on the front of the block, then the engine was intended for truck or bus use. Most truck and bus applications were produced with a steel crankshaft instead of a nodular iron crank.

330

Smallest bore of the FE engines with a 3.875˝ bore; only used in truck applications.

332

Used in Ford cars in 1958 and 1959, as well as in Edsels during the same period.

352

Introduced in 1958 as a replacement for the Lincoln car engine, the 352 engine is also known as the Interceptor V8. Basically, the engine was a stroked 332 that produced 208 hp with a 2-barrel carburetor. The Interceptor Special V8 was a 4-barrel version that produced 300 hp. It was used in Ford Thunderbirds and Mercury Marauders between 1958 and 1960.

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361

First FE engine offered in 1958 Edsel Ranger, Pacer, Villager, Roundup and Bermuda.

360

Produced in Ford F Series trucks from 1968 until 1976.

390

Produced in 1961, and the most commonly known engine among the FE family, this engine was used in many of Ford’s cars and trucks. The 2-barrel version produced 265 hp and the 4-barrel version produced 320 hp. In 1967 and 1968, the 4-barrel version produced 335 hp and was installed in the Mustang, Fairlane GT and “S” code Mercury Cougars. Another high performance version was available with 3×2 barrel carburetors and produced 401 hp.

406

Start of the Generation II engines. Had the same stroke of the 390 but had the bore of 4.130˝. The bigger cylinder bores required thicker cylinder wall block design. The main bearing caps were cross-bolted, which kept the caps from walking under harsh racing conditions. The 406 was only available for less than two years until the 427 was introduced.

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410

Used in 1966 and 1967 Mercury cars, the 410 had the same bore of the 390 (4.050˝) but had a longer stroke of 3.980˝, which is the same as the 428.

427

Produced in 1963 with the same stroke as the 390 but with a bore of 4.230˝. There were two different versions known as top-oiler and side-oiler. The top-oiler, same as other “FE” engines, delivered oil to the cam and valvetrain and then to the crankshaft. The side-oiler had a passage from the oil pump down the side of the block to deliver oil to the crankshaft first then to the camshaft and valvetrain.

427 SOHC

Also known as “the Cammer,” the SOHC 427 was built in 1964 to compete in NASCAR against the Chrysler 426 Hemi. The SOHC 427 engine was hemispherical combustion chamber design with a single 4-barrel carburetor that produced 616 hp and 515 lb ft. of torque. Even though the engine met homologation requirements of NASCAR (meaning that the sanctioning body required that X number of these engines had to be sold to the public to prove that the engine was not intended for race-use only), the engine was still banned from racing. This has been the only engine that NASCAR ever banned in its history.

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428

With the big bore of the 427 (4.235˝), manufacturing became expensive. Ford utilized the biggest stroke of 3.985˝ and a bore of 4.135˝ to make a 428 c.i.d. engine. The engine was used in 1966 and 1967 Ford Thunderbirds, Mustangs, Galaxies, and Cougars.

428 Cobra Jet

This engine was built in 1968 with heavier connecting rods and nodular iron crankshaft that made a rated horsepower of 335 but actually was 410 horsepower. The 428CJ had larger intake ports and valves than any other production FE cylinder head with 2.06˝ intake valves and 1.66˝ exhaust valves. All other FE cylinder heads shared the same valve sizes of 2.02˝ intake and 1.55˝ exhaust.

428 Super Cobra Jet

Built for more abusive and race applications, the Super Cobra Jet had heavier rods that used cap screws instead of bolts. It also utilized an engine oil cooler. As with the 410, all 428 crankshafts were externally balanced because removal of the center counterweight required an external counterweight.  

Building an FE

Obviously, what wasn’t a failure about the Edsel was its engine. Even though the FE engines have been out of production for over 30 years, they are still noted for their great torque and power. Aftermarket manufacturers have stepped up to the plate and continue to offer a lot of performance parts for these engines. Thankfully, that included my friend’s 390.

All Ford “FE” blocks have either “352” or “501” at the top right corner of the engine. Most blocks have the “352”. In most cases, the best way to identify the cubic inch is to tear the engine down and measure the bore and stroke.

Though it had apparently been rebuilt before he bought it, we soon realized the Galaxie’s  FE needed some serious attention. After trying to salvage the internal engine components and perform a simple rebuild, we quickly changed our minds and decided to build a stroker engine from what was left.

Upon tear down, we proved the engine was a 390 cubic inch engine with points distributor, aluminum dual plane Shelby intake, 750 double pumper carburetor with manual choke, and had a set of 1-7/8˝ headers, which are unique and wrap around the frame of the car. The engine had been bored .030˝ over and fitted with a set of dished pistons and a hydraulic flat tappet camshaft.

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Machine work was totally unacceptable. The bores were all out of round and had anywhere from .006˝ to .009˝ of bore taper. The valve guides in the cylinder heads were completely worn and the crankshaft looked as though it was starting to eat the main bearings. Also, the camshaft was very hard to turn in the block.

The cylinder heads were a set of 390 GT 14 bolt exhaust heads had received some minor port work, with 2.08˝ and 1.65˝ valves and a set of larger diameter springs..

These cylinder heads had some minor port work with new valves and a set of larger diameter springs.

We hoped that we might be able to salvage the heads, pending further teardown.

Above the oil pan rail at the base of the oil filter adaptor is where the date code has been cast. For this block which ended up as a 390, has a code of 8F27 meaning May 27, 1968. On the side of the FEn you will often find three letters (DIF) with a number to the left. This block was cast at the Dearborn Iron Foundry using mold #30.

We found another stock 390 block that we could bore and transfer all the parts. The original cast crankshaft was in rough shape but we hoped we could remachine it, get some new bearings and gaskets and transfer all the parts. There was only one glitch in our plan – the crankshaft was actually in worse shape than we first thought and no amount of work could salvage it. Luckily, since the FE remains so popular there are several companies that cater to the hotrodders who love them. You can fairly easily find several different options for a complete rotating “stroker” bottom end assembly.  Typically, the rotating assembly package consists of three different crankshaft strokes to choose from 3.980˝, 4.125˝ or 4.250˝, compared to the stock stroke, which was 3.780˝.

If the exhaust ports would have been 8 bolt holes instead of 14, the application would have been general purpose for 390-428 cubic inches. The C8AE-H is considered to have medium rise intake ports which are smaller than the ports found on the low rise intake. Valve sizes for this cylinder head were found to be 2.08” intake and 1.65” exhaust with a 72 cc combustion chamber. The valve sizes and chamber along with the 14 bolt exhaust would match that of performance use found in the 390 Mustang or GT 500.

We were able to pick exactly what worked best for our customer’s needs because these crankshafts are available in forged 4340 or cast nodular iron and fitted with FE main journals 2.438˝ and smaller big block Chevrolet rod journals, which are 2.200˝. The stroker assembly also came with a choice of H-beam or I-beam rods with a choice of two different lengths: 6.490˝ (stock) or 6.700˝ and premium forged pistons with flat-top or dish design.

We were still planning on a budget build, so weneeded to determine what stroke was best. We felt the stock iron cylinder heads were ok, so if we used them we felt that a small stroke increase would be beneficial and still give us some additional cubic inch displacement. We found a rotating assembly consisting of a cast 4.125˝ stroke crank, H-beam connecting rods, and .030˝ over flat top pistons and rings.

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We bored and honed all the cylinders to a consistent 4.082˝, align honed the mains, and decked the block .017˝, bringing the pistons out of the bore above the deck about .003˝.

The rotating assembly arrived so we checked the balance of the crankshaft assembly with our flywheel and clutch components and ended up adding some Mallory to the crank. The clearance checks on the connecting rod bearings and main bearings averaged from .0027˝ to .003˝ on the mains with .005˝ of thrust clearance and .0024˝ to .0026˝ on the rods.

The pistons had .0055˝ cylinder bore clearance and the rings were filed to fit with .018” on the top ring and .022” on the second ring.

Heading Into Head Work

Once we were satisfied with the bottom end, we were faced with another roadblock. The guides in the cylinder heads were worn, the valve seats were literally destroyed and the valve faces were pitted and would not clean up in the valve grinder.

With such a nice and beefed up bottom end in this FE the only way to complement these internal components was to use a set of aluminum heads.

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Of course, the word budget came up again, but at this point we had thrown it out the shop door. Aluminum cylinder heads for the FE are pretty common and you can find several different versions of the FE cylinder head that will fit a variety of FE engines at a reasonable price.

We chose a bare cylinder head with unfinished seats and guides because we wanted to do our own port work and fit the heads with our choice of valves for this bore size. Stock size valve stems on the FE is 3/8˝ and we were going to install 11/32˝ stem valves.

The rocker arms are not oiled by the pushrods. The block deck has a passage on the driver’s side that feeds the cylinder heads from the #2 cam bearing journal and the passenger side is fed by a passage from the #4 cam bearing journal. These passages were restricted by tapping the deck and using a 3/8” set screw and drilling a .078” hole. This prevents the top end from over oiling on acceleration and is recommended when using an aftermarket rocker system.

Since the 390 has a small bore compared to the 427, we custom ordered 2.15˝ intake valves and 1.65˝ exhaust valves. Once we received them, we sent the heads to Brian Maloney of Maloney Competition Systems in Martinsville, VA, for comprehensive head work: new valve guides, a multi-angle valve seat job and porting of the heads.

To further compliment the cylinder heads, we wanted to upgrade the existing stock rocker stands. Not knowing our camshaft profile at the time, we considered the idea of a solid-roller camshaft. Whatever camshaft we used would be more aggressive, some stronger rocker shafts and supports along with roller tip rockers would be cheap insurance for our application.

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The stainless rocker arm system we chose fits engines from the 352 through the 428 c.i.d., and comes complete with sixteen 17-4 ph stainless steel alloy 1.75 ratio rockers (with silicon bronze bushings), hardened shafts, individually numbered billet aluminum rocker shaft supports and spacers, aircraft quality studs, 12-point nuts, shims, ball style lash adjusters and pushrod length checkers. The system is designed to fit all low and medium rise, tall port OEM production and aftermarket cylinder heads. 

One speed bump that we had to iron out was the pushrods. The pushrod may be a small component in the engine, but it plays a very important role. The rocker arms we were using fit a variety of applications, so the first step was to correctly space the rocker arms in relation to the valve placement in the cylinder heads. Once the rocker arms were correctly shimmed and torqued on the cylinder heads, the correct length pushrod could be determined for proper rocker arm geometry. This length was determined by using two adjustable pushrods furnished in the rocker arm kit. Since the length was uncommon (9.25˝), we knew they would need to be custom made.

The “raw” Edelbrock cylinder heads for the FE came out really nice with quite a few hours in the seat work and porting.

Factory pushrods for the FE had a 3/8˝ diameter and our new rocker arm set up also demanded a 3/8˝ diameter. To know exactly which type (correct material and thickness) of 3/8˝ diameter pushrod would work best in our operating range, we needed answers to some critical questions such as open spring pressure, cam profile, cylinder pressure, and rocker ratio. With our combination, we had an open spring pressure of 597 lbs., a 1.75:1 rocker ratio, and with our cam profile we determined that our new pushrods needed to be made with 4130 chrome-moly tubing 9.25˝ long with a wall thickness of .140˝.

After receiving the pushrods and installing them, one thing we realized is that the top of the pushrod holes in the head had to be chamfered. When trying to set the valve lash, the pushrod was barely touching the top of the pushrod hole. So we machined the tops of the pushrod holes to eliminate the scrub and properly set the valve lash.

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Fuel System Upgrade

Since our project had progressed into a beautiful piece of art with some really nice parts, we ultimately figured we should bring the old into the new. We really wanted to give this FE a modern day appeal. The original engine was carbureted, so why not complement this build with modern day fuel injection? Our plan was to dyno test the engine first using a carburetor with electronic ignition and then bolt on the fuel injection to compare.

The rear cam plug is installed backward compared to typical engines with the cup side facing outboard.

For our combination, we chose a multi-point system, which came with an aftermarket single plane intake, 1375 cfm throttle body, 36 lb. injectors (we opted for 60 lb. because we wanted to make more than 500 hp), wiring harness and ECU, fuel pump and all related sensors, fittings, and fuel line.

By choosing the fuel injection we could modernize the vehicle but also wanted to improve drivability and hopefully gain some fuel efficiency. It’s not that we couldn’t tune the carburetor for various driving conditions because that is what we could have done years ago.

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When the fuel injection kit arrived, we also sent the intake manifold to Maloney Competition to be ported. The as-cast runners in the intake manifold were in need of some attention and would not support the power gains we were in hopes of.

After the port work and changes were completed on the cylinder heads and intake we had to get some flow numbers, not only to see where we stood, but to also help design the camshaft profile. Understanding airflow is critical to know where to fully open and close the intake and exhaust valves for maximum power for your application. Our combination yielded 11.0:1 compression with 431 cubic inches, so with our ported cylinder heads and intake along with our 1-7/8” headers and four-speed transmission, a custom grind camshaft was in order.

We wanted the engine to have great throttle response, good vacuum and low-down stump-pulling torque, but still make some horsepower on the top end. Camshafts are a unique science and because there are only a handful of people who can see these events and understand them, they are often poorly ground.

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I often use Dema Elgin of Super Lobes for my custom cams. Located in southern California, Dema has been in the camshaft grinding business since 1957. For this

 

application he recommended a lobe separation of 112-degrees on a single pattern grind with 261° of duration at .050˝ and .383˝ of lobe lift, which with 1.75 rockers would yield .640˝ lift with .026˝ of lash.

After having the camshaft ground, Comp Cams help sort out the rest of the valve train, including the appropriate valve springs, retainers, locks, lash caps, valve stem seals, shims and lifters.                          

Dyno Expectations

The differences between expectation and reality can quickly become hilarious, because at the start of our build we simply wanted to do a good rebuild and make some power. By the time we finished, we were looking to go drag racing because we felt we had a Pro-Mod power plant. Making power becomes an addiction: a little is not good enough. Just like the kid in the candy store, you want all you can get. So even though we had totally blown out a budget build on this one, we were dying to get on the dyno to see the results.

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But with our FE build almost complete, there were still a few things that we needed to iron out before we could dyno test the engine.

We had originally determined that our engine would be fuel injected with a multi-point system, but we wanted to establish a few parameters that could be used as inputs to our EFI system. We intended to dyno the engine two ways: first, we wanted to break the engine in and fine-tune it with a carburetor. Then, we would convert the engine over to fuel injection and compare power differences.

I thought this would be a great opportunity for a real-world comparison. Most of the time when you have an engine on the dyno, you’re optimizing it for the customer’s demands. If they want a carburetor, you optimize the engine with the carburetor. When there is fuel injection, you tune the fuel injection. You don’t usually have too many opportunities to dyno both systems on the same engine.

Of course, in order to dyno test both systems we had to outfit the engine for both configurations while the engine was on the stand so that dyno testing would be much easier.

All bearings and components were coated with assembly lube prior to installation.

An FE engine is a different breed from other Fords, with a different bell housing bolt pattern and motor mount configuration. Darryl Diamond of Diamond Research in Bethlehem, NC, has experience dyno testing FE engines and since he already had the necessary pieces to fit the engine to his Superflow dyno, we used his facility.

Darryl’s shop is a complete in-house engine machining and test facility founded in 1982 by his father Jesse and brother Chris. They owned their own racing team and ventured into various racing series such as NASCAR Nationwide, Late Model Stock, Goody’s Dash Series and Pro-Cup. In 1987, they expanded their operation and started building competitive racing engines for the public while racing their own team. In 2004, their father Jesse passed away unexpectedly and in 2005, they closed the car shop and concentrated on their engine program. To this day, their engines have powered over 300 wins.          

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With the help of Darryl’s employee Tracy, the engine was loaded in the dyno cell and ready for testing. For our initial testing, we choose a 650 CFM carb that was fully adjustable with changeable idle and high-speed bleeds. You may immediately worry that – since we started with a 750 CFM carb – 650 is too small. Rest easy – this carburetor is Darryl’s and had been fine tuned in a previous test session at his facility with a similar cubic inch engine. It would be a great starting point for our comparisons.

The ignition system for the carburetor test session was an HEI distributor out of a later model FE engine. With this distributor we could also use the socket style plug wires from our original engine. We used the wiring harness for the pick-up coil of the distributor to trigger the ignition box mounted in the dyno cell. The ignition coil was mounted on the front of the driver’s side cylinder head. For the fuel injection testing we would use a dual sync distributor, basically a cam and crank sensor for the fuel injection system. The crank sensor triggers the box to control ignition while the cam sensor is used as reference to fire the injectors.

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The EFI system is available with the option for the ECU to control ignition timing. We wanted to utilize this function and use our timing curve from the carburetor testing and input these parameters into the system.

After balancing, the Scat 4.125” stroke crankshaft was installed in the block.

While the engine was on the engine stand the dual sync distributor was installed and a custom set of plug wires were made and placed in a wire loom that bolted to the valve covers. Then we removed the distributor and neatly placed the custom made plug wires out of the way so we could install our HEI distributor back in the block for the carburetor testing. At the rear of the passenger side head, an aluminum plate was made to hold the ECU for the fuel injection and also an air fuel ratio meter to be used during the carburetor testing. The information that we obtain from the air fuel ratio meter could also be used as inputs for the fuel injection system.

So with the engine loaded on the dyno and set up for both kinds of testing, we were ready to fire. It is at this point in every engine build where I start feeling as though I’ve reached a crossroad. On one hand I’m happy because we’ve finally made it and I’m anxious to see the payoff in the end. On the other hand, in the back of my mind is Murphy’s Law: “what can go wrong, will go wrong.” In this case, it was Murphy who was wrong.

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With a push of the “start” button, the engine fired up flawlessly. We brought the engine speed up to around 2,000 RPM and watched closely as the engine began its break-in. We used purpose-designed break-in oil with the intention to get the engine up to operating temperature and then shut it down and let it cool. This gave the valve springs a chance to break-in with a good heat cycle and, while the engine was cooling, gave us a chance to check the valve lash on our solid roller.

The valve train set from Comp Cams included solid roller lifters p/n 839-16, valve springs p/n 943-16, locks p/n 611-16, retainers p/n 749-16, seals p/n 529-16, lash caps p/n 621-16, locators p/n 4785-16, and shim kit p/n 4757.

After the engine cooled, we fired it back up and checked over everything along with our ignition timing which we started out at 30° total. Our first pull we took the engine to 5,000 RPM while watching the air fuel ratio to see how the jetting of the carburetor would pan out. For the first pull, the air-fuel ratio was great, ranging between 12.5:1 and 12.7:1. We continued to make several more repeated pulls and the engine kept squeaking a little more power with each pull.

With the engine broken in we increased the engine speed , and at this point, the engine was making 513 horsepower at 6,000 RPM. We increased the total ignition timing to 32°. On the next pull, the engine gained almost 20 horsepower, making 531 horsepower. We advanced the ignition timing again to 34° and to our surprise, this time the engine made 547 horsepower. At this time, we were all surprised so we brought the ignition timing to a total of 35°. This time the engine made 555 horsepower at 6,000 RPM and 517 lb. ft. of torque at 5,100 RPM. The 35° of total timing is what the engine liked and we had tailored the timing curve on the lower RPM range. The amazing thing was that the torque was 501 lb. ft. at 4,000 RPM. The torque curve of the engine was almost flat having 500 lb. ft. in an RPM range from 4,000 to 5,400.

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Oh yeah, we were very happy. We had 431 cubic inches with 10.8:1 compression and would have been ecstatic if the engine made 500 horsepower on pump gas. But, 555 horsepower on pump gas in an FE Ford package?

Now we wanted to see if there were any differences so we converted to fuel injection. With the throttle body of the fuel injection system capable of 1200 cfm, we again worried that our 650 carburetor might have been too small for our testing. But there comes a point where big is not always best. There is a point of diminishing returns where the engine is only going to get the amount of air that it can take in. Would CFM differences shed some light? We would soon find out.

After installing the distributor and the fuel injection components we could test our fuel injection system. The oil was changed to 10W30 racing oil and the valves were re-adjusted. When the battery power was hooked up to the EFI system, we answered the preliminary questions on the handheld touch screen and supplied our inputs for the air fuel ratio and timing curve settings. The fuel system used was also part of the EZ-EFI system. After checking fuel pressure and making some adjustments, the engine was again ready for testing.

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When the “start” button on the dyno was pressed, the engine cranked and ran flawlessly. While monitoring the dash of the handheld, we could see the ECU learning and correcting and the engine was operating within the parameters that were specified. This turned out to be an easy and simple transition into a fuel injection system.

The plan was to make three moderate pulls on the engine, making sure that the ECU was learning with each pull. After each, we would cut the engine off and power down the ECU then power it back up again and continue to make some more moderate pulls. The way this system is designed to work, the ECU can only correct up to 25 percent of the air-fuel ratio in either direction (being rich or lean) with each ignition cycle. So, by letting the engine run then shutting it down and then turning it back on, the ECU could correct again an additional 25 percent to achieve its target air fuel ratio.

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The surprise came when, after three pulls, the engine was making close to the same power as the carburetor. When starting the engine for the fourth pull, we ran the engine up to 6,200 RPM and the dyno readings were almost identical to what the carburetor had produced. We continued to run the engine for several more pulls and the results remained exactly the same.

However, on the eighth pull, the power and torque started to decrease slightly. The engine seemed fine so three more pulls were made and the results showed more of a decrease in power. At this time, we cut the engine off and let the dyno cell fans run to cool the engine off and drop temperature in the room. After about 25 minutes, the engine was fired back up – the power and torque were back up again. We continued to make three more pulls and the engine held steady, but on the fourth pull the power again started dropping back off.

For years, top engine builders have seemed to prefer a carburetor over fuel injection and my question has always been “Why?” Fuel injection is recognized for its precise tuning capabilities, so why is the carburetor still used in a lot of racing classes where fuel injection is permitted? This comparison on the FE shed some light on the reasoning.

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The cooling effect of the carburetor is always worth more consistent power because it helps drop the intake manifold temperature. As we found with the multi-port fuel injection system, when the temperature rises in the intake manifold there is no cooling effect from the fuel and the power begins to descend. This fact can be very important to a racer.

On the other hand, how many street rodders dyno their engine and fine-tune their carburetor? Carburetors that are not fine-tuned can be a nightmare to the daily driver and weekend hotrodder. I think a good scenario for this situation would be to install a fuel injection system with the injectors installed in the throttle body. This way you could get the best of both worlds.

This FE engine build more than met our expectations. The build consisted of top brand quality parts that all proved very reliable. The engine had more than 25 dyno pulls in various configurations during our testing and never once gave us any issues due to our build. Anyone interested in turning a 390 FE into 431 cubic inches can easily find the parts and, with a little bit of work and creativity, can have 555 reliable and drivable horsepower for whatever situation they face.

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From my experience, the FE truly lived up to its heritage in terms of torque and power and the total cost was not as bad as you might expect. My customer was extremely pleased with his newly created vintage of iconic American history. ν

 

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