Dig in and prepare to get your hands dirty. It's time to add some cubic inches to your 5.0L Mustang, and it just might be easier than you think. With the average EFI 5.0L Mustang now some 20 years old, it's going to be time for a rebuild. For a few bucks more, you can add more cubes, more horsepower, and more torque.
A few issues back, we brought you a budget rebuild story called the "Recession Special." Adding new crank and rod bearings, along with new piston rings can freshen a tired 5.0L and give you a few more years of life from the tough-as-nails small-block Ford. This month, we're here to show you that you can employ those same techniques from the budget build and add a stroker rotating assembly at the same time.
Competition Products supplied...
Competition Products supplied our rotating assembly. It's competitively priced at $1,089.95 (PN SS331FF) and includes a cast steel crank, 4340 steel rods with ARP cap screws, flat-top HRC forged pistons, connecting rod and main bearings, and file-fit plasma moly rings. For an extra $200, we had Competition Products balance the assembly.
We started with a seasoned 5.0L stock block and dropped it off at H&M Parts Warehouse in Jacksonville, Florida, where the crew bored the cylinders 0.030-inch over, performed a finish hone, and installed new cam bearings, freeze plugs, and oil-galley plugs--not bad for just a little over 200 bucks. Most stroker assemblies utilize custom pistons that move the wristpin higher in the piston to allow for the longer connecting rod, and since they're already making a new piston to allow for more cubic inches, it just makes sense to maximize the piston to do the same. That being the case, the pistons are made for a 4.030-inch bore size. We also had the machine shop hot-tank the block before they gave it back to us.
For our rotating assembly, we turned to Competition Products of Oshkosh, Wisconsin. Since 1970, the company has supplied engine builders and enthusiasts alike with great deals on everything from engine parts to oil. If it's under the hood or beneath the chassis, chances are Competition Products has something to replace it or make it better. After placing our order, we had the rotating assembly sitting at our doorstep in just three days. It might be quicker if you live closer, as it ships the same day the order is placed.
The piston-ring end gap was...
The piston-ring end gap was filed to fit the cylinders according to SRP's instructions. The top ring was filed for a 0.022-inch gap and the bottom ring for a 0.028-inch gap.
The engine will be shoehorned between the fenders of a Fox-body coupe Mustang, so we opted for the 331ci stroker rotating assembly as opposed to the 347ci option. It's a light car, and we'd rather forfeit the extra torque of the 347 for the better rod ratio the 331 offers. There's only $10 difference between the two kits. The basis of the 331ci combo is a cast steel crankshaft with a 3.250-inch stroke on the rod journals. Said journals swing 5.4-inch Scat I-beam connecting rods that have been fitted with ARP fasteners. Finally, an octet of SRP forged flat-top aluminum pistons will fill the cylinders and get the crank and rods moving.
Competition Products also includes HRC plasma moly file-fit piston rings and balanced the entire rotating assembly for us. The company also provided us with a Professional Products harmonic balancer for the stroker's 28-ounce imbalance, as well as an SFI flexplate to match our Mustang's C4 automatic transmission.
The HRC piston rings were...
The HRC piston rings were filed and the end gap checked within the cylinder bore.
Topping off our stroked and poked short-block is a set of Trick Flow Specialties all-new Fast as Cast 190cc Twisted Wedge cylinder heads. TFS heads have always been relatively affordable, and in this day of CNC this and that, the company opted to give its consumers a CNC-sized port in a cast head for a cast price. Going off of its popular CNC-ported 185cc runner Twisted Wedge head, TFS used the port designs to produce a 190cc intake runner and 66cc exhaust runners. These 190cc runner heads retail for $1449.95, compared to the CNC-ported 185cc castings that sell for $1799.95.
"Our competitors have everyone believing that you need a CNC head to make power," says Trick Flow tech Greg Changet. "Some people will want a CNC head no matter what you tell them, but with the Fast as Cast head, you get the big runner without the big price." And you get the flow numbers, too. We'd like to see what a quick cleanup job could do with these heads, and we may get to that in a future article.
 We installed the crank bearings,...  We installed the crank bearings, coated them with assembly lube, and set the crankshaft into position. The main caps were torqued, and assembly lube was applied to the rod journals. |  The cast-steeL crankshaft...  The cast-steeL crankshaft included in the Competition Products stroker assembly was chosen for its durability in a street and strip environment. It'll still be in one piece long after we split the block, if we get that far in power production. |  The connecting rods in the...  The connecting rods in the Competition Products assembly are 4340 forged-steel, I-beam pieces from Scat. They're fitted with ARP cap screws and thankfully cleared our stock-block so we didn't have to perform any of the normal grinding commonly associated with small-block Ford stroker engines. |
 With all of the piston rings...  With all of the piston rings filed for a perfect fit, the pistons were fitted to the rods and installed in the block. SRP provides plenty of instructions with the pistons to make sure you have the piston rings clocked correctly. |  We took a photo of another...  We took a photo of another stroker engine build to show you where you'd need to clearance the block if you encountered interference with the rotating assembly. This engine utilized the same 3.25-inch stroke and 5.4-inch long connecting rod as our build, but it used an H-beam-style rod, which has more meat on the big end of the rod. The extra metal moves the cap screw location towards the end, which is where the block interference occurs. |  To let this 331ci small-block...  To let this 331ci small-block breathe, we called up Trick Flow Specialties and ordered a set of its brand-new Fast as Cast 190cc Twisted Wedge cylinder heads. Part number TFS-51400015 nets you aluminum Twisted Wedge heads that feature 2.020-inch intake valves and 1.60-inch exhaust valves. Trick Flow used its CNC-ported 185cc runner port design and cast it into a new head. That way you get the flow of the ported head at a cast price. The 190cc heads utilize a 7/16-inch rocker stud size, as well as 5/16-inch pushrods. |