Exclusive Content
Original Shows, Motorsports and Live Events
Due to the EU’s Global Data Protection Regulation, our website is currently unavailable to visitors from most European countries. We apologize for this inconvenience and encourage you to visit www.motortrend.com for the latest on new cars, car reviews and news, concept cars and auto show coverage, awards and much more.MOTORTREND.COM
  • |
  • |
  • The Diesel That Saved Ford

The Diesel That Saved Ford

Why The 6.4L Power Stroke Was A Game-Changer

Mike McGlothlin
Oct 1, 2011
I think it’s safe to say I’m a huge 6.4L fan. Don’t get me wrong, I’m one of what seems like very few who still appreciates the HEUI injection system (and I love my 7.3L), but the 6.4L made the Power Stroke brand competitive in today’s 600hp, daily-driver market. It’s an engine that’s come a very long way in a short amount of time.
Photo 2/2   |   Be sure to check out Jared Rice’s ’10 F-350 in this issue. His story of getting addicted to easy power gains is common for 6.4L owners.
Easy Horsepower
There’s just no denying how well these engines respond to simple modifications—even if you’re a Chevy or Dodge fan. When word spread that more than 300 hp could be added with just a tune, the EFILive camp and many Duramax owners took notice. Add in the fact that $1,700 to $2,000 could net you 550 hp at the wheels, and you start to see why even the Cummins community was buzzing about the 6.4L.
For the June issue, we attended a dyno event during which 13 of the top 20 most powerful trucks were ’08 to ’10 Super Dutys—and all but one made more than 500 hp. The majority of them were equipped with simply an intake, exhaust, and a performance tune of their choice.
The Right Ingredients
How was 540 to 580 rwhp achievable with just a tune, you ask? You’ve heard us say it time and time again, but common-rail injection and compound turbos were the key ingredients that left a lot of room for growth on the table. At the heart of it all sat the Siemens VDO K16 injection pump, which has been proven to outflow a comparable Bosch CP3 by as much as 20 percent. And to be fair, the factory lift pump is (surprisingly) able to supply enough low-pressure fuel to the K16 (even though fuel pressure could drop considerably when lengthy pulse widths were commanded).
And even though the factory compound turbo arrangement would be considered small in the diesel aftermarket, the 52mm/65mm combination will still support 600 rwhp. When tuned, the restriction provided by the stock turbos led to great spool-up and huge torque numbers. Our own Project Godzilla made 570 hp and 1,153 lb-ft (Dec. ’09 issue), and a six-speed F-350 made 585 hp and 1,185 lb-ft (Oct. ’09 issue).
Tough As Nails
The other piece of the power-making puzzle is a robust rotating assembly. Like the 6.0L, the 6.4L engine uses a bedplate bolted to the bottom of the engine to hold the crank in place. And because the engine’s water jackets don’t protrude into the lower portion of the block, filling it isn’t a necessary reinforcement measure in a high-horsepower build. How hard have enthusiasts pushed the stock 6.4L short-block? Diesel Power Challenge 2011 competitor Shone Patel’s F-350 laid down 911 hp on fuel during the dyno event and then squeaked out 1,158 hp on nitrous (if you don’t already know, 6.4Ls respond very well to N2O, too).
Record-Setting
Shone Patel’s corrected 911-rwhp number set a fuel-only record—not only for the 6.4L, but for all Power Strokes. Another big fish in the Power Stroke pond is Aaron Rudolph, whose Pro Street Super Duty has produced the highest nitrous-assisted dyno numbers to date: 1,213 hp. It should come as no surprise that his 6,260-pound, fiberglass-bodied F-250 also currently holds the record for the world’s quickest fullsize Ford, running a 9.49-second quarter-mile. Even more impressive, a trap speed of 147 mph on that pass means the truck could be getting as much as 1,350 hp to the pavement. Sure, he’s hurt his fair share of parts along the way, and the bulletproofed 5R110 TorqShift is on the ragged edge every pass, but every competitor encounters some kind of issue at this power level.
Have I sold you on the 6.4L yet? Maybe I’ve sold myself on it based on its power potential and all the success stories I’ve heard. I think the diesel industry will continue to embrace this powerplant for years to come due to its hot rod nature. Despite its short production run (three years) and the fact that the last 6.4L-powered Super Duty was produced roughly two years ago, the aftermarket is constantly developing new, cutting-edge parts for them. Three months ago, a complete stroker version of the engine was released to the public (“The Modern-Era 7.3L Power Stroke,” July ’11). And more recently, the first set of billet-aluminum competition heads was unveiled.
Whether you’re looking for the ultimate tow rig, a reliable 700hp daily driver, dyno queen, or competition vehicle, the 6.4L platform has not only proven it can perform—but that it can last.
- OF

POPULAR TRUCKS

MOST POPULAR

CLOSE X
BUYER'S GUIDE
SEE THE ALL NEW
NEWS, REVIEWS & SPECS