440 cubic inches used to be the domain of rip-snorting big block engines. Even more specifically, the number 440 denoted the rip-snorting big blocks produced by Mother Mopar and the Pentastar Kids.
That was then, though. Thanks to the proliferation of high-quality factory and aftermarket blocks and stroker kits, you can build 440 cubies out of what used to be labeled small blocks. Many of those big-inch engines now wear bowties and blue ovals rather than pentastars, and thanks to fuel injection, CNC-ported heads, roller cams, and other modern wonderfulness, make horsepower that would send the big blocks of yore slinking home with their carburetors between their legs (if they had legs, that is).
To prove our point, we present this LS motor built by Trick Flow Specialties. It’s got it all going on-440 cubic inches, Trick Flow GenX™ Street/Strip aluminum heads with 235cc intake ports, Lunati/Diamond rotating assembly, .629 inch lift Lunati roller cam, F.A.S.T. EFI intake…oh yeah, and one of the first LSX Bowtie blocks out of the GM Performance Parts foundry. As exotic as the engine sounds, all the parts are readily available items-and worth 680 horsepower on Trick Flow’s Superflow engine dyno.
Want to know more about this small block 440 powerhouse? Of course you do. We’ll begin this two-part story with the short block, based on GM Performance Parts’ LSX Bowtie block. Designed from the get-go for high-horsepower, large cubic inch applications, the cast iron block comes with 3.990 inch semi-finished bores that can go out to 4.250 inches; combine that with a 4.500 inch stroke crank and you’ve got 482 cubic inches.
The LSX block also features the following goodies:
- Extra-thick siamesed cylinder bores
- Cross-bolted, ductile iron main bearing caps
- Windowed main bearing bulkhead-better crankcase breathing and windage control for improved high rpm power without reducing block strength
- True priority main oiling system-prevents oil starvation at main bearings, improves upper engine oil control
- Cylinder head decks can be machined to 9.200 inch height
- Six head bolt locations per cylinder bore for better head and gasket retention with high compression or forced induction
- Rear oil feed line for use with dry sump oiling system
- Cam bores can be machined for 60mm diameter roller cam bearings
- Screw-in freeze plugs at front and rear of block can be removed for use with engine heaters or coolers
- Motor plate mounting bosses on the front of the block for drag and circle track racing applications
- Additional (7th) transmission mounting bolt hole to accommodate early (pre-LS) GM transmission mounting pattern
The LSX block accepts most regular LS-spec parts, including cranks, pistons and rods, camshafts, cylinder heads, valvetrain, oiling system components, and external stuff like motor mounts-no need to pony up for expensive “race-only” parts. Unless you want to, of course.
Crank, Rods, and Pistons
Building 440 cubic inches with an LSX block requires 4.125 inch bores and a 4.125 inch stroke. Lunati provided the stroke in the form of a Pro-Series crankshaft. The crank is whittled from 4340 steel alloy and features cross-drilled mains for improved oiling, 7/8″ lightening holes in the #2, #3, and #4 rod journals, and .140″ radii on rod and main journals to reduce chances of fatigue cracking. Lunati also supplied the 6.125 inch I-beam rods; they’re also 4340 steel forgings that come weight-matched (+/-1.5 grams) and have ARP cap bolts.
The pistons were sourced from Diamond Racing. The forged slugs come with a ceramic thermal barrier coating to reflect heat back into the combustion chamber where it belongs, and a dry film moly coating on the skirts to reduce friction. The pistons have a -10.6cc dish that yields a 10.8:1 compression ratio with the 70cc combustion chambers in the Trick Flow GenX Street/Strip 235 cylinder heads.
It was Lunati to the rescue again when it came to the bumpstick. It supplied a healthy hydraulic roller, custom-ground for the 440. It features 262° intake/270° exhaust duration @ .050 and .629 inches of valve lift with a 1.7 ratio rocker.
Odds and Ends
Odds and Ends Other parts Trick Flow used to complete the LSX short block include:
- Comp Cams adjustable timing chain set
- Clevite H-series main and rod bearings with TriArmor moly/graphite coating
- ARP main stud kit
- Fel-Pro gasket set, GM Performance Parts head gaskets
What’s cool about building an LSX short block-or any LS-based engine, for that matter-is how simple it is to assemble. At the fundamental level, an LS is just a pushrod 90 degree V8; if you’ve built a small block Chevy, you can build one of these. Open up the accompanying slide show and we’ll show you.
GM Performance Parts LSX Bowtie Block
Lunati Pro Series Billet Crankshaft, 4.125″ stroke
Lunati I-Beam Connecting Rods, 6.125″
Lunati Hydraulic Roller Camshaft, .629” lift (special order)
Comp Cams Adjustable Timing Chain Set
Clevite H-Series Main Bearings, TriArmor coated
Clevite H-Series Rod Bearings, TriArmor coated
ARP Main Stud Kit for GM LSX
Diamond Pistons: www.diamondracing.net
GM Performance Parts LSX Block
Fans of monster LS engines, rejoice. GM Performance Parts now offers an affordable foundation for a big-inch LS motor—the LSX iron block. The need for such a block was obvious due to the limitations of production LS blocks. 1999 and later aluminum blocks can go up to 427 cubic inches (4.125″ bore with a 4.250″ crank) only with expensive resleeving (the blocks use iron sleeves). Iron 6.0L truck blocks can be overbored up to .060″, but core shift problems require careful sonic checking. The LSX block doesn’t have either problem. It can be bored out to 4.250″, requires no resleeving or sonic checking, and can accept stroker cranks up to 4.500″. That translates into 482 cubic inches of ground-pounding Gen IV engine if you so desire. Best of all, the LSX block is a screaming deal at around 2 grand.
The crankshaft will ride 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.
Crankshaft, Rods, and Pistons
Trick Flow decided to build a 440 cubic incher out of its LSX due to the optimal bore to stroke ratio (4.125″ bore and 4.125″ 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″ lightening holes in the #2, #3, and #4 rod journals, and .140″ 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″, and the secondaries to .020″.
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″ to .0078″; Trick Flow’s came out at .0060″. 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°/270° duration @ .050″ valve lift (320°/329° advertised) and .629″ 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 4 degrees advanced on a 110° 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.