Here at Mustang & Fords, the midnight lamp is always burning over some classic Ford project. This time it's a Factory Five Racing Mk III Roadster that Editor Houlahan has gotten us involved with, and he has horsepower on his mind.
The original FE big-block-powered Cobras had a 427ci displacement. This is a nice target size to have from both horsepower and nostalgia standpoints. It's plenty of displacement for a car that barely weighs a ton, and the number has always had a notorious ring to it. That size engine is now easily created using the 351 Windsor engine as a basis. It allows the builder to utilize a whole array of high-performance equipment that has been developed recently. While there have been some excellent power-enhancing advances made with FE engines, there is far less to choose from by comparison. Parts for FE engines are also much more expensive.
Our Dart Windsor bare block...
Our Dart Windsor bare block features four-bolt main caps on crankshaft journals two, three, and four. As you shall see, the outer main-cap bolts are splayed and enter the block at an angle for enhanced strength. The Dart casting is far more robust than a stock or Sportsman block in many critical areas, particularly the support webbing around the main journals. This block arrived with a 4.125-inch bore ready to go. We'll need to install freeze plugs and cam bearings to begin.
It's a good thing we know Ben Smeding at Smeding Performance, because horsepower is what he does best. Smeding will personally assemble one of his 427 Cobra Special engines for our Snake Charmer project using some of the most advanced components available. We'll even transcend the typical stock or Ford Sportsman 351 Windsor block offerings and use an aftermarket cylinder block from Dart Machinery. Fully CNC-ported aluminum cylinder heads from Air Flow Research (AFR) and a Competition Cams custom-ground roller cam will add to the potent recipe.
For engine induction, the optimum in fuel efficiency and driveability comes from fuel injection. On this engine, we'll use a Mass-Flo EFI system, which is based around the proven Ford EEC-IV EFI electronics. This system uses mass-air technology with a centrally mounted throttle body for easy packaging and killer "classic" looks.
Follow us to Smeding Performance in Rancho Cordova, California where we'll witness the actual engine build. Then we'll transfer the mill directly to the company's in-house engine dynamometer. Once on the engine dyno, the 427 will be run for break in. After that, we'll do some pulls and see how much horsepower the Smeding Performance 427 Cobra Special is worth while running on EFI. Check it out.
On the Dyno
Once the Smeding 427 was complete, the staff at Smeding Performance had our 427 bolted to their in-house DTS Powermark engine dyno in no time flat and were ready to let all 427 cubes loose. While Smeding's engine packages usually feature a carbureted intake and a carburetor fitted to the specific needs of the engine, we asked Ben Smeding if he would dyno our engine with the Mass-Flo EFI system. After setting up the dyno with the proper fuel pump and regulator, complements of Holley, we ran the engine to let the ECM learn and to stabilize oil and water temps, and then made our power pulls.
| 427W w/Mass-Flo EFI |
| RPM | Torque | Hp |
| 2,600 | 477.3 | 236.2 |
| 2,800 | 497.4 | 265.2 |
| 3,000 | 500.2 | 265.7 |
| 3,200 | 498.2 | 303.5 |
| 3,400 | 510.0 | 330.1 |
| 3,600 | 521.6 | 357.5 |
| 3,800 | 534.9 | 387.0 |
| 4,000 | 547.2 | 416.7 |
| 4.200 | 556.4 | 444.9 |
| 4.400 | 552.4 | 462.8 |
| 4,600 | 557.4 | 488.2 |
| 4,800 | 537.2 | 491.0 |
| 5.000 | 516.8 | 492.0 |
| 5,200 | 486.6 | 481.8 |
| Max TQ: 557.4 at 4,600 rpm |
| Max HP: 497.3 at 4,900 rpm |
As you can see by the above dyno chart, our 427 with the Mass-Flo EFI system is a torque monster--500 lb-ft of torque at 3,000 rpm in a 2,200-pound car borders on insanity, but we never said we were playing with a full deck. We were just shy of the magic 500hp number (hey, what's 2.7 hp between friends when you won't be able to put it all to the ground anyway?). Smeding rates its 427 at 520 hp, and we're sure with a little more tuning we would be able to find that 20 hp, but in such a light vehicle we weren't worried about it. Ben Smeding tells us that his 427s will often dyno anywhere from 520-550 hp with a carb, depending upon build options.
Looking at Smeding dyno runs of similarly built 427s, the Mass-Flo puts more torque and horsepower on the table at lower rpm, but the carb breathes a bit more at all-out rpm. The Mass-Flo puts the power in a more usable rpm range and also gives us that great driveability, fuel economy, and easy starting that EFI is so widely known for. We think those benefits are worth the cost of admission--and you can't beat the looks of the Mass-Flo EFI system for a classic car, either.
It's The Main Thing
 This photo shows the Ford...  This photo shows the Ford Sportsman 351 cylinder block at the main saddle. Take note of the thickness of the cap structure and also the thickness of the support webbing underneath the main cap going out to the pan rail. |  This view of the Dart cylinder...  This view of the Dart cylinder block is from the same perspective. The dramatic difference in the construction between the two blocks speaks for itself, especially the main webbing as it goes to the pan rail. |  Here are the two different...  Here are the two different main bearing caps side by side. Besides the four-bolt retention, with the outer two being splayed, the Dart piece shows far heavier construction. The Ford part is bored to accept the standard 351W 3-inch bearing diameter, while the Dart piece is set up for the smaller 23/4-inch Cleveland-sized bearing. |