Add the main studs to the block with a healthy dose of oil on the threads. All steel items, whether they're pressed in or threaded, need oil to keep them from gaulding and tearing up the aluminum threads in the block. Make sure #3 and #4 mains get special ones with extra threads for windage tray and oil pump pickup. After using special body shop lint free pre-cleaning cloths, dabbed in ATF to clean the bores, clean the bearing surfaces with a good evaporative solvent such as alcohol.
Unlike its small-block predecessor, the 4.6 engine utilizes the #5 or last main bearing to perform the thrust duties. Windsor small blocks were one of the only engines to use the center or #3 bearing cap. All of the upper bearings (with oil grooves and holes) are the same with the thrust washer being a separate one-piece 180-degree washer. At first it looks odd with the lower thrust bearing capturing both sides of the crank and the top just capturing one, especially since the GT 2V cast iron block uses both on top and bottom. We're not sure about their philosophy here, but it must work because it has never been the subject of any of the many engineering changes.
Push the crankshaft rearward when you're installing the thrust washer to create the proper clearance for the unit. Clean all main bearing cap surfaces with solvent and add the lower bearings to the caps. Push the crank back towards the front of the block to install the lower thrust bearing main cap. Install the rest of the main caps and stud nuts with lots of oil.
The ARP studs do not use the factory's torque to yield (TTY) method, which involves a final turn of 90 degrees after the final torque wrench setting. However they do still use the factory tightening sequence with the outers getting 30 lbs.-ft. and the inner 60 lbs.-ft. "We use ARP for the entire engine; the ARP studs have a much higher 130,000-lb. tensile strength, which is far better than the factory stuff." John told us.
The crankshaft endplay is then checked to be within the .005-.015 factory setting. We then add the side adjusting screws, checked the endplay, add the side bolts and checked it again. Give the crank a few turns to make sure you haven't put it in a bind while pre-loading it. A methodical approach to properly secure the crankshaft in a free state will assure your stroker engine a long life.
Now it's time to assemble the piston and connecting rod assemblies. The stock pistons' pressed in wrist pins use a retaining ring where the full floating type of the stroker kit uses double (meaning two locks per side) spiral locks. They come flat and you pull them apart, so they look like a spring before installation. This locks them into the ring groove and makes them very easy to install.
At SHM, pre-torquing the rod bolts is always standard procedure as they have, on rare occasion, gotten bad bolts. After placing the connecting rods in a rod vise and torquing in several steps until the .005-.006 stretch is obtained, the specific torque settings are noted. They will be used when the rod assemblies are installed on the crankshaft, assuring the optimum settings are utilized. (Usually around 70 lbs.-ft.) This is always recommended by the manufacturers as added assurance of the bolt's proper heat-treat process.
Each ring is carefully placed squarely in the bore and checked with a feeler gauge then precision-ground to obtain its respective target gap. Then you carefully add the rings to the pistons, noting the exact location of the gaps in accordance to the included manufacturers' spec sheets. Use a ring compressor to install the piston and rod assemblies in their respective cylinder by the numbers and arrows on the rods. Torque them on the crankshaft to the pre-recorded spec from the bolt-stretch operation. "We like to snug them all, then torque them to spec after they are all on the crank," explained John. Check rod side clearance after the torque procedure by prying both rods to one side, then check the gap with your feeler gauges-it should check .005-.017. Next add the windage tray with the standoffs and torque them to 100 lbs.-in.
Now this is definitely the coolest engineering feat of the modular motors: the rear seal retaining cover. It contains a one-piece seal that presses into the cover. You just add some petroleum jelly to the seal and a bead of silicone on the mounting surfaces, as it doesn't use a gasket. On the other end, install the oil pump gears to the housing and torque the lid to 100 lbs.-in. It doesn't need silicone because it has an O-ring groove around the housing for, you guessed it, a huge O-ring.
We always recommend adding a dab of red Loctite on the pick-up tube bolts then torquing them to 89 lbs.-in. and the pick-up brace bolts to 20 lbs.-ft. Always replace the O-ring in the pick-up tube where it mounts to the pump. Install the oil pan and torque to 24 lbs.-in. The factory gasket comes with cool little steel grommets built in to prevent the bolts from over compressing the gasket.
This assembly process applies to any '95-98 4.6 4V Cobra engine short-block. Hopefully you've found some helpful tips to aid in assembling your project or maybe just to teach you exactly what makes one of these Modular motors tick.
Next month we'll take the mystery out of installing the timing chains and how they work. We'll also bolt on the cams and install the lifters and rockers, and, finally, "The Tale of the Tape" will be revealed, as we get a readout from the dyno test of the big Sean Hyland 5.2 Stroker Modular Motor.