Project LSX: Trick Flow Specialties Builds a 440 with a Bowtie (Part 1 of 2)

The crankshaft rides on a set of Clevite H-Series main bearings with TriArmor coating. This exclusive moly/graphite coating reduces friction—which frees up horsepower and some extra rpms—and extends the life of the bearings and the crank’s main journals. The Clevite bearings are also chamfered to clear the beefy fillets on stroker crankshafts.

Trick Flow decided to build a 440 cubic incher out of its LSX due to the optimal bore to stroke ratio (4.125-inch bore and 4.125-inch stroke) and parts availablity. Lunati provided said stroke in the form of a Pro-Series crankshaft. Forged from 4340 steel alloy, the crank features cross-drilled mains for improved oiling, 7/8-inch lightening holes in the #2, #3, and #4 rod journals, and .140-inch radii on rod and main journals to reduce the chances of fatigue cracking. Lunati also supplied the 6.125-inch I-beam rods, forged from the same good 4340 steel as the Pro-Series crank. The Lunati rods come weight-matched (+/-1.5 grams) and have ARP cap-style fasteners.

Lunati balanced the reciprocating assemble for the 440. Note the slugs of heavy, or Mallory metal in the front counterweight. The slugs were welded in to make sure they didn’t pop out at an inopportune moment, like during a full-throttle dyno pull. That would be bad.

The LSX block can be set up to use the early LS1 (24X) or later LS2 (58X) crankshaft position sensor and matching reluctor wheel, depending on which type of engine management system you wish to use. The ACCEL DFI engine management system used by Trick Flow requires the early 24X reluctor wheel to function properly.

Diamond Racing custom-made the forged pistons for Trick Flow. The pistons have a -10.6cc dish that provides a 10.8:1 compression ratio when combined with the 70cc combustion chambers in Trick Flow’s GenX Street/Strip 235 cylinder heads. The crown has a ceramic thermal barrier coating to reflect heat back into the combustion chamber where it can do the most good--make power. Diamond also applied a dry film moly coating to the piston skirts to reduce friction. Diamond supplied the piston rings as well (1.5mm top and secondary, 3.0mm oil control). Trick Flow gapped the top rings to .018 inches, and the secondaries to .020 inches.

The nodular iron main bearing caps are included with the LSX block. Each cap is cross-bolted to add additional strength and rigidity to the crankcase. GM includes a full set of main cap hardware (inner bolts, outer studs, and side bolts) with the LSX block. The GM main studs and bolts are torque-to-yield, which requires the use of a torque angle gauge to achieve proper load. Trick Flow substituted a set of stronger ARP studs, which don’t require the torque angle gauge. The side bolts are torqued to 20 ft.-lbs.; ARP recommends putting a dab of RTV silicone sealant under the bolt heads to prevent oil leaks. The inner cap studs get torqued to 60 ft.-lbs., the outer studs to 50 ft.-lbs. All torque values are based on use of moly assembly lube.

Crankshaft endplay is measured with a dial indicator on the snout, which measures endplay as the crank is moved forward and backward with a screwdriver. The factory tolerance range is .0015-inch to .0078-inch; Trick Flow’s came out at .0060-inch. If the endplay is excessive, a thicker thrust bearing can be used. If endplay is too tight, the thrust bearing surface on the crank must be ground down to achieve the proper bearing clearance.

The piston and rod assemblies are slid into their respective bores. Trick Flow used TriArmor-coated Clevite H-series rod bearings in the connecting rods to further reduce friction and extend bearing life.

A spin of the reciprocating assembly revealed a clearance problem; the underside of the pin bosses on #8 piston contacted the reluctor wheel at the bottom of the piston stroke.. Not good news, as it meant removing the piston/rod assembly to remove a slight amount of material from the edge of the pin boss as shown. As this 440 was one of the first LSX block-based engines built, some glitches were to be expected.

With the clearance problems addressed, the piston and rod went back in the block. The rod bolts were torqued to 70 ft.-lbs.(using the supplied assembly lube) and fingers were crossed as Todd spun the crank. Thankfully, everything spun around as it was designed to.

Next on the install list was the Lunati hydraulic roller camshaft. Ground to Trick Flow’s specifications, the cam specs out at a very healthy 262-degree/270-degree duration @ .050-inch valve lift (320-degree/329-degree advertised) and .629-inch lift. While the cam is a custom grind, you can get one just like it for your LS engine—just ask for part number 55099LUN and grind number 50-262-270. You don’t even have to worry about sourcing cam bearings—GM provides a set that is specific to the LSX block. If you really want to get trick, the journals can be machined for use with 60mm diameter roller cam bearings, which will really reduce the friction and help the valvetrain hit those high notes.

The LSX block comes with this cool steel camshaft thrust plate. The plate uses an O-ring for sealing, and is held in place with these nifty buttonhead bolts. The General thinks of everything, doesn’t he?

Comp Cams supplied the double roller timing chain set. The LS2-style chain features hardened billet steel gears, a heat-treated chain with large, heavy-duty link pins, and a Torrington thrust bearing for smooth operation. The cam sprocket allows virtually infinite timing adjusts up to 6 degrees advance or retard; the crank sprocket allows additional adjustment up to 4 degrees.

Todd put the Comp Cams chain’s adjustability to good use when he degreed in the camshaft. The cam ended up four degrees advanced on a 110-degree intake centerline.

The last item before moving upstairs was tapping in the front oil plug, which prevents oil loss from the main oil gallery. The plug must be tapped flush with the front of the block; if it is too far in, the plug will block the flow of oil to the oil pump.