Project Strokers Wild (Part 4): Dyno-Testing our Ford Stroker Engines

Three hopped up Ford motors. 960 cubic inches. Hundreds of horsepower. Enough torque to pull down small office buildings.

After building our Stroker’s Wild series of Ford stroker engines–a 347-cubic-inch 5.0L, a 393-cubic-inch 351 Windsor, and a 520-cubic-inch 460–the time had come to strap them to Trick Flow Specialties’ Superflow dynometer and start whomping on ’em. We were either going to make some big numbers, or we were going to blow stuff up trying.

Fortunately, nothing broke, nothing went wrong, and the dyno printouts proved what we knew all along—there’s big power in stroker motors. In our case, a lot of that has to do with the careful parts selection and engine assembly done by the folks at Summit Racing.

OK, enough with the blabbering and backslapping. Let’s see how much power these Fords made…check out the images below for results.

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347 C.I.D. Five Liter for v8 on engine dyno

The R-Series intake manifold from trick flow

engine horsepower dyno chart for 347 ford engine build

393 C.I.D. 351 Windsor v8 on engine dyno

engine horsepower dyno chart with 1-7/8 inch headers

520-cubic-inch big block Ford v8 on stand

engine horsepower dyno chart with 1/8 inch headers

engine horsepower dyno chart for powerport engine test

347 C.I.D. Five Liter We set up our 347 as a fuel injected engine. The 10:1 compression long block is topped with a Trick Flow R-Series EFI intake manifold, a 70mm BBK throttle body, and 24 pounds-per-hour fuel injectors. A Ford EEC-IV computer controlled fuel and spark delivery for the dyno testing. You can read about the engine buildup in Strokers Wild: Part One.

The R-Series intake manifold is designed to produce power from 2,500-7,250 rpm, making it ideal for strong street and bracket racing engines. The lower intake has short, large cross-section runners that are biased to midrange and high-rpm power. Intakes with long, small cross-section runners (the factory Ford 5.0L intake, for example) are more biased to low-rpm torque. Trick Flow has many other EFI intakes for 5.0Ls and 351Ws.

As the dyno results indicate, our 347 has the right parts combination to make good power—over 400 peak horsepower and 395 foot-pounds of peak torque.

393 C.I.D. 351 Windsor As outlined in Strokers Wild: Part Two, we stroked a 351W out to 393 torque-monster cubes. For the dyno test, we topped the engine with an Edelbrock Victor Jr. intake and a 750 cfm Holley double pumper. This induction combination helped build power in the upper rpm ranges.

The Scat cast crankshaft is the key to making the big Windsor an affordable proposition. The 3.850-inch stroke crank fits both one- and two-piece rear main seal blocks. Just add a .030-inch cylinder overbore, stock length 351W rods, stock-style 302 pistons and presto—393 cubic inches.

With a pair of 1 7/8-inch primary headers and 36 degrees of total timing, the 393 belted out 529 peak horsepower and 472 foot-pounds of peak torque. Just as we hoped, the power peaks occurred way up in the powerband. Still, there was plenty of torque available down low, with just a touch over 375 foot-pounds of the stuff available at 3,000 rpm.

Our 520-cubic-inch big block Ford features a 4.300-inch stroke crankshaft, 6.700-inch long Eagle Specialties rods, a .718-inch lift Crane solid roller cam, and Trick Flow A460 heads. You can check out the build in Strokers Wild: Part Three.

The A460 aluminum heads feature 91cc closed-style combustion chambers for high compression use, raised 340cc intake ports for improved flow, and small cross-section runners to keep airflow velocity high. The heads come assembled with 2.300-inch/1.88-inch stainless steel valves, 1.640-inch dual valve springs, 10 degree valve locks and titanium retainers, ARP rocker arm studs, and guideplates.

With a 1,050 cfm Holley Dominator perched on a Trick Flow R-Series A460 single plane intake, 2 1/8-inch primary headers, and 34 degrees of total timing, the 520 thumped its way to 752 peak horsepower and 660 foot-pounds of earth-spinning torque. Even at 3,000 rpm, there were over 530 foot-pounds of torque available.

Think 752 horsepower is good? Trick Flow dyno-tested its new and improved PowerPort A460 340 heads and R-Series A460 intake on the same 520-cubic-inch short block outlined in this article. The only other changes were shorter Trick Flow pushrods (9.100-inch intake/9.550-inch exhaust), and 1.73- ratio Trick Flow roller rockers. The new heads and intake added over 50 horsepower (805 vs. 752) with peak torque essentially a wash (659 vs. 660 foot-pounds). Progress is a wonderful thing.