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  • Inside the “6.3L Power Strokerrr”…J&K Engines All-New, Ford V-8

Inside the “6.3L Power Strokerrr”…J&K Engines All-New, Ford V-8


KJ Jones
Jan 29, 2016
Photographers: KJ Jones
There’s really no need to get too deep into the common parts failures (head gaskets, EGR coolers, and so on) that have contributed to Ford’s 6.0L Power Stroke having one of the worst reputations (for diesel engines) ever. The problems—which are corrected by installing fairly simple hardware such as ARP cylinder-head studs, multi-layered-steel head gaskets, lifters (yes, those, too), and Bulletproof Diesel’s EGR and oil coolers—are known by almost everyone who has any involvement with the diesel scene. And, no thanks to Internet forums and social media, a lot of misconceptions about 6.0Ls are still being communicated.
The truth is, yes, 6.0L Fords have a few issues. However, as we learned at the 2015 Diesel Power Challenge, when the failure points are addressed through a stout rebuild and with turbocharger, fuel, and exhaust upgrades, the beleaguered engine can actually be a player in the performance game. Case in point: the engine in DPC 2015 Third Place finisher Jesse Warren’s ’09 F-350, which uses a compound-turbocharger setup, big injectors, a fuel system, and nitrous oxide to make more than 1,000 hp.
Not long after DPC, we heard that the crankshaft in that engine had given up the ghost and bent. While we weren’t by any means surprised to hear that news (because 900 to 1,000 horses is largely recognized as the maximum range for a 6.0L’s power before catastrophic failures occur), just knowing these engines have the ability to put out that much steam when properly built definitely gives us and many other enthusiasts newfound respect for the redheaded stepchild in Ford’s diesel group.
As the light of acceptance for—well, better understanding of—6.0L engines continues to shine brighter, we’re very excited about a unique new engine concept from J&K Engines, which is derived from that very powerplant: a 6.3L (383ci) torque maker that until now (and yes, we checked) is an engine many engine experts believed was impossible to build using the ’03-to-’07 6.0L Power Stroke. And why did many think the 6.3L couldn’t be done? Because until now, no one knew the secret to mating an ’08-to-’10 Ford 6.4L crankshaft with stock “Six-Oh” everything else (block, rods, pistons, injectors, and such).
J&K’s owner, Jack Cammarata, is very lucky to have a true “dynamic duo” on his staff: lead builder Keith (he requests that we not publish his last name) and machinist Kermit Ayres, the guys who have successfully turned a wild idea into an all-too-real creation that just might silence the 6.0L naysayers for good. The J&K Engines “Power Strokerrr” 6.3L Ford V-8 is that powerplant, and we were given an exclusive opportunity to see and experience one (yes, we drove the company’s work truck that the beast is installed in) during a trip to J&K’s Mt. Juliet, Tennessee, facility.
Enjoy the photos and captions as we shadow Keith through his assembly of a new 6.3L long-block. While bolting the parts in place is one aspect of the build, the science behind making the crankshaft fit is amazing (the 6.4L’s connecting-rod journals are considerably larger than those of a 6.0L), and the performance gleaned from increased displacement (365 ci to 383 ci) is amazing for an otherwise-stock 6.0L.
As you read on, it’s important to note that since a lot of detailed calculating and precise machine work goes into building the engine, and, with respect to the landmark research and development Keith and Kermit have done, we’re not providing exact measurement data, math formulas, and such that they came up with for making the Power Strokerrr. However, the proof it can be done is all here, including dyno results confirming the 6.3L Ford’s mettle, as it easily put 445 hp and 850 lb-ft at the rear wheels of J&K’s 8,700-pound ’04 F-250 shop truck.
Photo 2/40   |   001 Jk Engines Stroker Engine Build Keith
Keith of J&K Engines (Mount Juliet, Tennessee) lowers an ’08-to-’10 Ford 6.4L crankshaft—the heart and soul of the company’s unique, new “6.3L Power Strokerrr” diesel powerplant—into the saddle of a 6.0L Ford block. “That’s not possible,” you say? Read on!
Photo 3/40   |   002 Jk Engines Stroker Engine Build Block
According to Keith and company owner Jack Cammarata, remanufacturing 6.0L Fords is J&K Engine’s primary business. “All our blocks are prepared the same way, with extra attention given to line-honing the crankshaft bore,” Keith says. “So many people believe the ‘fixes’ for these engines are only in the EGR, cylinder heads, and lifters. By ensuring the crank line is perfect, we’re essentially making a 6.0L’s bottom end capable of supporting much more power than what many people believe is the maximum, without suffering catastrophic damage. We set this engine up to be perfect for work trucks, but it’s also ready to take on performance upgrades such as multiple turbochargers and big injectors and make serious power.” Cylinders are bored 0.040 over, high- and low-pressure oil galleys are drilled and tapped for screw-in plugs, all gasket surfaces (decks, front and rear) are smoothed, and metal parts that touch and create any sort of friction (bearings, piston skirts) are treated with PolyDyn performance coatings for 6.3L Power Strokerrr builds.
Photo 4/40   |   003 Jk Engines Stroker Engine Build Pistons Rods
Take away the 6.4L crankshaft and 0.040-inch replacement pistons, and the remaining hard parts for a 6.3L Power Strokerrr (connecting rods, lifters, and such) are all stock 6.0L Ford. The stroker’s entire rotating assembly is also precision balanced.
Photo 5/40   |   004 Jk Engines Stroker Engine Build Crank Comparison
Photo 6/40   |   005 Jk Engines Stroker Engine Build Crank Snout Comparison
Here are examples of a stock 6.4L crankshaft (top and left) and the same crank after it has been modified and polished by Kermit to his own exact specifications. Note the extreme difference in the snout, which is turned down and rounded (from 2.798 inch) for compatibility with the snout bore in a 6.0L engine’s front cover. Two keyways that help secure the harmonic balancer are also added. Reducing the snout and all machine work forward of it (front cover, G-Rotor and its cover, and the damper) is handled by Industrial Machine & Tools of Nashville, Tennessee.
Photo 7/40   |   006 Jk Engines Stroker Engine Build Rod Measurement
Zach Wolfe measures the 6.4L crank’s rod journals (2.835 inch). For stroker engines, Kermit machines the journals down 0.010 inch, which enables them to accept stock 6.0L rods.
Photo 8/40   |   007 Jk Engines Stroker Engine Build Main Measurement
Main-journal size (3.189 inch) is the common denominator for 6.4L and 6.0L Power Stroke engines.
Photo 9/40   |   008 Jk Engines Stroker Engine Build Cam Bearings
Photo 10/40   |   009 Jk Engines Stroker Engine Build Cam Installed
Each 6.3L Power Strokerrr also features PolyDyn-coated 2.438-inch camshaft bearings. A stock cam is being used for our engine build, but J&K can install application-specific bumpsticks, per customer request.
Photo 11/40   |   010 Jk Engines Stroker Engine Build Main Bearing
Photo 12/40   |   011 Jk Engines Stroker Engine Build Crank Installed
Once main bearings are installed, the 6.4L crankshaft is placed in its saddle in the 6.0L block, and the cradle is positioned on top of it.
Photo 13/40   |   012 Jk Engines Stroker Engine Build Cradle Gasket Goop
Keith uses only a small dab of gray silicone at each edge of the cradle seal to hold the gasket in place when the cradle is flipped over and installed.
Photo 14/40   |   013 Jk Engines Stroker Engine Build Cradle Install
Photo 15/40   |   014 Jk Engines Stroker Engine Build Cradle Bolts
It’s important to note that the crankshaft-cradle bolts are different lengths. The shorter fasteners are installed on the outside edge of the cradle, and longer bolts go inside.
Photo 16/40   |   015 Jk Engines Stroker Engine Build Torque
Keith torques each crank-cradle bolt with 170 ft-lb. Unlike cylinder-head studs or other fasteners in the engine, there are no “steps” or increases for torque values.
Photo 17/40   |   016 Jk Engines Stroker Engine Build Piston Surface
Photo 18/40   |   017 Jk Engines Stroker Engine Build Notched Piston
All eight Mahle pistons are decked (0.065 inches of material removed) to help achieve the engine’s unique stroke, and then coated with PolyDyn HS Gold for better heat dissipation. A few slugs require notching for clearance with the aggressive throws of the 6.4L crankshaft’s counterweights.
Photo 19/40   |   018 Jk Engines Stroker Engine Build Rod Bearing
Standard-size 6.0L rod bearings cannot be used in J&K’s 6.3L Power Strokerrr, as they will actually skew the engine’s cubic-inch displacement. Oversized (0.025 inch) bearings are used for our build.
Photo 20/40   |   019 Jk Engines Stroker Engine Build Piston Rings
Keith indexes piston rings at the 3:00 (oil), 12:00 (second) and 6:00 (top) positions—the common ring stagger for 6.0L Ford diesels.
Photo 21/40   |   020 Jk Engines Stroker Engine Build Torquing Rod Bolts
Connecting-rod bolts receive 30 ft-lb of initial torque and then are stepped to 52 ft-lb of final tightening.
Photo 22/40   |   021 Jk Engines Stroker Engine Build Front Gasket
OEM Ford gaskets, seals, and fasteners are used throughout a 6.3L Power Strokerrr short-block assembly.
Photo 23/40   |   022 Jk Engines Stroker Engine Build Front Cover
Photo 24/40   |   023 Jk Engines Stroker Engine Build Oil Pump Machine Work
Photo 25/40   |   024 Jk Engines Stroker Engine Build Front Cover Install
Only minimal modifications are required for the stock 6.0L front cover; a small amount of material is removed from the snout bore to ensure there are no clearance issues between the tip of the crank, the cover, and the G-rotor components. Keith also adds dime-sized dabs of gray silicone to the lower corners of the cover. Failure to do this is guaranteed to result in an oil leak…immediately.
Photo 26/40   |   025 Jk Engines Stroker Engine Build 6
Photo 27/40   |   026 Jk Engines Stroker Engine Build Machined Oil Pump Gear
Here is a look at the G-rotor, before and after modifying by Industrial Machine & Tool.
Photo 28/40   |   027 Jk Engines Stroker Engine Build Front Seal
An aircraft-style, carbon/graphite, Teflon-to-Teflon front oil seal is used for the stroker application. According to Keith, “because of the unique size of the G-rotor bore in the front cover, the seal was designed specifically for this engine, and it absolutely will not leak.” A special tool for 6.4Ls is required for installing it.
Photo 29/40   |   028 Jk Engines Stroker Engine Build Stock Balancer
Photo 30/40   |   029 Jk Engines Stroker Engine Build Machined Balancer
This is a comparative look at the rear face of a stock 6.0L balancer (black) and a similar piece that has been modified (recessed, slotted bolt holes) for compliance with the snout of the 6.4L crankshaft. The balancer is secured with fasteners positioned at the outermost point of each slot.
Photo 31/40   |   030 Jk Engines Stroker Engine Build Balancer Install
Photo 32/40   |   031 Jk Engines Stroker Engine Build Complete Short Block
Developed around the perfectly machined crankshaft and front cover of 6.4L and 6.0L Ford Power Stroke engines, J&K’s 6.3L Power Strokerrr is an all-new torque monster that puts to rest any notion that “Six-Ohs” can’t make power.
There Are Options…
A small-but-impressive assortment of additional pieces is offered for the J&K Engines 6.3L Power Strokerrr. Cylinder-head studs and gaskets, high-volume water pumps, and custom PCM calibrations are all available as extra-cost options. It’s still unclear whether the stroker as a full long-block assembly will be among these options, but J&K’s engine builder Keith was kind enough to put one together for us—just so we can see how this new diesel looks with heads, a valvetrain, and a water pump attached.
Photo 33/40   |   032 Jk Engines Stroker Engine Build Calibration
Of course, having the correct PCM calibration is critical for any fuel-injected engine, as it allows a powerplant to perform at its full potential. An SCT X4 flash programmer loaded with a Brad Sweat custom tune (made specifically for 6.3L strokers that retain the stock injectors, airbox, and son on) can be purchased directly from J&K.
Photo 34/40   |   033 Jk Engines Stroker Engine Build Arp Head Studs
Zach Wolfe installs ARP cylinder-head studs and multi-layered-steel gaskets before bolting down a set of remanufactured stock heads. J&K Engines’ 6.3L Power Strokerrs are primarily sold as short-blocks. However, full long-block assemblies may be offered in the future.
Photo 35/40   |   034 Jk Engines Stroker Engine Build Water Pump
Bullet Proof Diesel’s 100mm water pump is also available as an option.
Photo 36/40   |   035 Jk Engines Stroker Engine Build Long Block
Photo 37/40   |   036 Jk Engines Stroker Engine Build Short Long Block
On the Dyno
When it comes to improved performance, increasing an engine’s cubic inches almost always makes a marked and, in this case, awesome, difference. Although we didn’t perform a baseline test on the chassis dyno, we confidently estimate the 6.0L Power Stroke diesel in J&K Engines’ ’04 Ford F-250 shop truck made roughly 270 hp prior to the build and installation of the 6.3L powerplant. With custom SCT tuning by Brad Sweat of Southern Trucks and 4x4, more than 445 hp and nearly 850 lb-ft was achieved. “This engine has the potential to make a lot more power,” Brad says. We find “cool” in the fact that the power and torque come despite the engine not using any of the performance enhancers that typically help produce the same numbers with stock 6.0L powerplants. With the addition of power-adders and such, this new 6.3L engine could possibly be a reliable 1,000hp player, and the Power Strokerrr solidly affirms that good things really can come from Ford’s 6.0L diesel engine.
Photo 38/40   |   037 Jk Engines Stroker Engine Build Burnout
Although it’s designed for trucks that are put to work on a daily basis (hauling, towing, and such), J&K Engines’ 6.3L Power Strokerrr Ford also brings plenty of fun to the game. The engine’s 445 hp and 850 lb-ft of torque make tire-roasting burnouts happen at the mash of the throttle and promote acceleration that makes the fact that you’re driving an 8,700-pound truck very hard to believe.
Photo 39/40   |   038 Jk Engines Stroker Engine Build Complete
Once installed and fully dressed with the remaining stock-Ford components, the 6.3L Power Strokerrr looks right at home in the engine bay.
Photo 40/40   |   039 Jk Engines Stroker Engine Build Dyno Graph


SCT Performance
Sanford, FL 32771
Polymer Dynamics
Houston, TX
Industrial Machine & Tool
J&K Engines
Southern Trucks and 4x4