AFR Cylinder Heads

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AFR Cylinder Heads_Chevrolet_Big Block_18°_457cc_Rectangular Port_90cc_Assembled_Solid Roller

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Price $3,476.00

Product Code: AFR-3708

Description

Technical Specs

AFR 457cc 18° Big Block Chevy heads are the best performing, highest flowing head in the BB Chevy lineup. They come standard with stainless steel 2.400 intake and 1.800 exhaust valves. The intake port is raised .500 and the valves are rolled to 18°, resulting in unparalleled flow numbers under the curve and feature 90cc combustion chambers . This head is ideal for 540CI or larger race engines and requires specific pistons, valve covers, shaft mount rockers while utilizing readily available intake manifolds. AFR offers a wide range of options and upgrades; including titanium valves and copper seats. AFR heads are available bare (without parts), call our tech line for details

457cc CNC Ported Intake Runners
A356 Aluminum
11/32 Bronze Valve guides
5 angle valve job
Precision CNC machining
Multiple spring options

Assembled heads feature:

11/32 Bead Lock Intake Valves
11/32 Bead Lock Exhaust Valves
PAC Racing Valve Springs
7/16 ARP Rocker Studs
3/8 Adjustable guide plates

www.P65Warnings.ca.gov

Description
Item Code	AFR-3708
Vendor	Air Flow Research
Product Type	Cylinder Heads
Product Model	Magnum
Engine Family	Chevrolet 18°
Weight	54

Included Components

Combustion Chamber	100% CNC Ported
Intake Ports	100% CNC Ported
Exhaust Ports	100% CNC Ported
Valve Job	Competition 5 Angle
Intake Valves	11/32 Bead Lock Stainless Intake Valve - 2.400 x 6.035 Overall Length
Exhaust Valves	11/32 Bead Lock Stainless Exhaust Valve - 1.880 x 5.935 Overall Length
Valve Springs	PAC Racing Spring - 1.645 OD - Solid Roller Dual Valve Spring - 350 lbs on seat - .950 maximum lift - 8,300 to 8,500 Max RPM
Retainers	10° Titanium - 1.500 OD x 1.180 ID x .765 ID
Keepers	10° 11/32 Lock w/Lashcap Recess
Rocker Studs	7/16 ARP
Guide Plates	3/8 Adjustable
Valve Seals	11/32 Viton
Spring Seat Cups	1.740 OD x 1.650 ID - Hardened
Intake Valve Seat	Ductile Iron - 2.500 OD x 2.000 ID x .375 Deep
Exhaust Valve Seat	Ductile Iron - 1.900 OD x 1.400 ID x .375 Deep
Valve Guides	11/32 Bronze - .502 OD x 2.700 Overall Length

Recommended Components

Intake Gasket	AFR-6880
Note	Important: Do not use your AFR gasket as a template to port match your intake manifold as one AFR gasket is used for many AFR runner volumes.
Exhaust Gasket	AFR-6858
Head Gasket	Fel-Pro 1057 or Cometic C5434
Head Bolts	n/a
Head Studs	ARP 135-4305 12 pt
Head Bolt Washers	Manley
Stud Girdle	n/a
Intake Manifold	AFR 4902 (9.800) AFR 4901 (10.200)
Spark Plug Starting Range	Autolite 3932
Distributor	MSD 84697 or 8489 (9.800) or MSD 85661 or 8547 (10.200)

Specifications and Features

Material	A356 Aluminum
Intake Port Volume	457cc
Intake Port Dimension	2.490 Height x 1.750 Width - 1/2 Radius
Intake Port Location	Raised .500
Exhaust Port Volume	143cc
Exhaust Port Dimension	1.850 Height x 2.090 Width
Exhaust Port Location	Raised .450
Combustion Chamber Volume	90cc
Valve Cover Bolt Pattern	Perimeter Bolt
Valve Angle	18/4° Intake _ 11°/4° Exhaust
Valve Spring Pocket Diameter	1.750 OD
Max Valve Spring Pocket Machining	1.750 OD
Note	Warning: Do not increase spring pad depth
Deck Thickness	.750
Minimum Bore Diameter	4.600
Flat Mill	.005 per cc
Angle Mill	.0066 per cc
Note	Angle milling may require .120 thick intake gasket
Minimum Cross Sectional Area	3.699 sq in
Spark Plug Dimensions	14mm x .750 w/Gasket Seat
CARB EO Number

Flow Chart

Flow Data: cfm @ 28 inches of Water

Lift	.200	.300	.400	.500	.600	.700	.800	.900	1.000
Intake	161	254	331	389	439	479	492	495	498
Exhaust	134	201	251	286	305	315	332	337	342

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