CHEVROLET PERFORMANCE RACE BLOCKS
Chevrolet Performance Race Blocks are all about serious horsepower. Precision is the operative word for them, from start to finish, so you can depend on them to get you to the finish line first. Chevrolet Performance Race Blocks use only the highest-grade materials and machining techniques. The blocks are CNC-machined with closer tolerances than Bowtie blocks. Race blocks feature full race-prep machining and 4-bolt splayed main caps. Chevrolet Performance Race Blocks have proven themselves repeatedly in NASCAR and NHRA-sanctioned races. Chevrolet Performance race blocks have the power and reliability to put your car in the winner’s circle.
Chevrolet Performance Race Block Technical Notes:
• Precision CNC-machining means +/- 0.001-inch tolerances.
• Cylinder bore wall thickness is 0.225" minimum at 4.155" bore. A sonic bore check data sheet is provided with block
• Nominal wall thickness of cylinder bores is 0.340"
• Cylinder decks, front and rear of case, oil pan rail surfaces and head dowel pins are blueprinted
• Extra-thick deck surfaces have blind-tapped head bolt holes for superior head gasket sealing
• Enlarged cam bosses allow custom machining for larger bearings
• Non-standard cam bearings are required (see each block for details)
• Extra-thick main bearing bulkhead is machined at 5°
• Bearing cap inner bolts are spread 0.210" to allow machining for 400 journal crankshafts
• Premium quality main studs and SAE 8620 steel main bearing caps
• Priority main oiling system
• Billet wet sump rear main cap can be adapted to dry sump with plugs
• 2-piece rear main crankshafts and pre-1986 oil pans are required
• Use of some aftermarket mechanical roller lifters may require clearancing top of lifter bores
• Timing system clearance should be checked before engine assembly
• Lifter valley oil scavenging boss below bell housing flange is not drilled or tapped
• Oil dipstick holes are not drilled
283 Main, 350 Bore Size Short-Deck Bowtie Race Block
• CNC cast-iron competition block designed for drag racing, road racing or restricted oval track racing!
• 4-bolt steel mains, 20° splayed caps on center three mains
• 8.325" deck (Standard deck blocks are 9.025"), can be machined to 8.200" deck height
• Camshaft is raised 0.433" to 4.955"
• Cam bearing bores machined for 2.250" O.D. x 1.875 roller bearings
• 3.980" rough bore
• 4.185" max bore (minimum of .250" cylinder bore wall thickness)
• Integral oil restrictors
• Must use Big-Block water pump, must raise water pump with adapters for balancers larger than 6"
• Olds Aurora V-8 bell housing bolt pattern (12.25" max flywheel diameter)
• Lifter holes and cylinder head bolt holes are not drilled
• Will accept standard, SB2.2 and splayed valve lifter patterns
• Can be machined to accept any Small-Block Chevy cylinder head
• Shorter-than-production pushrods required
• Tested to over 800 horsepower!
• Water jacket core plugs are 1.5" press-in
• Oil galley plugs are AN O-ring style
•Part Number: 24502650
•Casting Number: 24502650C
•Deck Height: 8.325"
•Lifter Pattern: None
•Cylinder Wall: Siamese
•Bore Range: 3.980" - 4.185"
•Main Bolt: 4
•Main Bolt Degree: 20°
•Cap Material: Steel
•Crank Journal Size: 283
•Seal Type: 2 Piece
•Max Stroke: 3.250"
•Weight (lbs): 167
•Max HP: 800
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