Dart 31152211 Cast Iron Little M Sportsman Engine Block Chevy Small Block 400 Mains, 4.125 Bore, Ductile Caps
Excellent racing, marine performance upgrade or stock replacement block. Street performance, Sportsman racing.
Dart’s Little M Sportsman block is the affordable alternative for Sportsman racers and serious street performance.
The Sportsman block shares most of the Little M’s best features, but saves you money by using Ductile Iron main bearing caps (4-bolt on the center three and 2-bolt on the ends), and employing a rear external oil feed, crossover and restrictor provision.
• Uses standard small block parts, including cam, timing chain, oil pump, oil pan, oil filter, motor mounts, mechanical fuel pump, and clutch linkage.
• Priority main oiling system feeds the main bearings first.
• Siamese cylinder bores with extra thick walls resist cracking and improve ring seal for more power (minimum .275” thick with 4.185” bore).
• Scalloped water jacket walls improve flow around cylinders for better cooling.
• Open lifter valley improves oil return to pan.
• Enlarged lifter bosses accommodate offset and oversize lifters.
• Blind head bolt holes don’t go through to water jacket.
• Splayed outer bolts on middle main bearing caps.
• Rear external oil feed, crossover and restrictor provision.
• Parts kit sold separately.
Material: Superior iron alloy
Bore: 4.125″ (unfinished)
Bore/Stroke: 4.185″ x 4.000″ (max recommended)
Cam Bearing Bore ID: SBC 2.00″
Cam Bearings: Specially-coated & grooved with three oil holes
Cam Bearing OS: +.010″, +.020″, +.030″
Cam Bearing Press: .002″
Cam Journal OD: Standard SBC 1.869″
Cam Plug: 2.375″
Cylinder Wall Thickness: .275″ minimum @ 4.185″ bore
Deck Height: 9.025″ +.005″to.008″
Deck Thickness: .675″ minimum
Fuel Pump: Mechanical pump provision
Fuel Pump Pushrod: Standard length
Freeze Plugs: Press-in cup plugs 1-5/8″
Lifter Bores: SBC .8427″ to .8437″
Main Bearing Size: 2.450″ (350), 2.650″(400)
Main Bearing Bore: (350)2.6401″/-.001″ (400)2.8401″/-.001″
Main Caps: Ductile iron, splayed center 3, 2 bolt front and rear
Main Cap Register: Deep stepped register on each side (no need for dowels)
Main Cap Press: .005″
Main Cap Bolts: 7/16″
Oil System: Wet sump, main priority oiling (can use dry sump)
Oil Pump Shaft: 350 main = stock shaft (.481″ OD), 400 main = stock shaft (425″ OD) MUST machine aftermarket shaft
Oil Filter: Standard SBC filter (uses 2-bolt filter adapter)
Oil Pan: Standard SBC oil pan
Rear Main Seal: 350 main, standard seal, 2-piece, 400 main- Felpro# 2909
Serial Number: On main caps and left front
Starter: Standard SBC
Stud Hole/Head: Blind holes
Timing Chain/Gears: Standard SBC components
Timing Cover: Can use stock stamped steel or plastic
Torque: 65 ft/lbs (7/16″ bolts), 35 ft/lbs (3/8″ bolts)
Weight: 175 lbs