Horse Sense: This report marks the close of what has become known around the office as "Version 1.0" of our Boss 340 engine project. This first iteration of our experiment with canted valves features Edelbrock's Performer RPM 351C 2V heads, a Wilson-modified original Boss 302 intake manifold, and a Probe Industries-built short-block based on Ford Racing Performance Parts' new Boss 302 engine block. While it ends with the dyno test detailed in this report, you can rest assured that we'll probably be deep in the throes of Version 2.0 activities by the time you read this. That's right-there's plenty more to come for this project, including the construction and running of a full-on, who-knows-how-many-second drag 'Stang by the time it's over.
Westech's Ernie Mena and Steve Brul put the finishing touches on our Boss 340 project engine. With its Edelbrock Performer RPM 351C 2V canted-valve heads, a beyond-radical '69 Boss 302 intake manifold by Wilson Manifolds, a Comp Cams hydraulic-roller bumpstick and valvetrain components, and Probe Industries' forged rotating assembly, we think this version of the Boss (we're calling it Version 1.0) should be capable of sending nearly 400 naturally aspirated horses to a street 'Stang's rear tires.
Ernie is Westech's resident EFI guru, and our engine test is his first look and tryout of ACCEL's Thruster EFI engine management system. "I'm really looking forward to working with this system," he says. "We've been getting calls from people asking for information on how it performs. Having this opportunity to work with it will be helpful."
Based on comments we've seen on our Web site's message board and notes we've read on some of the Mustang-specific message forums we peruse, it appears our Boss 340 (a modernized version of Ford's legendary Boss 302) engine effort has developed a fairly strong fan base since we first introduced the idea in our Mar. '08 issue ("The Comeback," p. 82). The attention our engine is getting is cool, and we hope the project has thus far been entertaining, but even more informative, especially for those of you who have been as curious about building canted-valve-headed 302s for Fox Mustangs as your tech editor has been since Ford brought back the Boss.
In retrospect, our fuel-injected, Boss-style bullet was done the hard way. While the short-block is comprised of the same internal gear that's used for 347 strokers-with the exception of pistons, which are Cleveland-head-specific pieces made by Probe-the cool, matched-set, top-half pieces (heads/intake manifolds, headers) that are now available, such as Edelbrock's new Performer RPM Clevor setup for 302-based engines and Kooks' Boss 302/8.2-deck, bolt-on, 2-inch headers for '79-'93 'Stangs, were still in development when we got started. We had to figure out what was needed and how to make it all work.
The FRPP oval-shaped Mustang air-cleaner assembly includes a slimline, 1-inch element that will do more harm than good on an engine such as ours, so Eugene is replacing it with K&N's 3-inch cleaner for greater airflow into the Wilson 1,130-cfm throttle body.
Putting it succinctly, we figured it out, and we must say that we couldn't have done it without the great help we received from the many manufacturers and service providers who believed in what we were trying to do-break new ground with engine technology in our ever-evolving Mustang world. In many instances, they went above and beyond with their assistance and support of this effort.
With that said, it's finally time to light our 340's fire and see if it indeed lives up to the "Boss" name. We've taken you through all of the conceptualizing, parts-gathering, and building stages of the engine in previous stories, and we're now at a point where our finished product must be put to the test.
It's all going down on the SuperFlow 902 engine dyno at Westech Performance Group in Mira Loma, California, where Ernie Mena and Eugene Walde are set to handle every step of the test process, which includes developing fuel and timing maps with ACCEL's newest addition to its DFI lineup, the Thruster EFI. The following photos and captions highlight events and processes that preclude our date with the dyno. Of course, the Boss engine's all-important performance statistics are also included.