AFR Cylinder Heads

Custom Piston Worksheet & Order Form (pdf)

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AFR Cylinder Heads_Chevrolet_LSx_12°_260cc_69cc_Competition_4.000 Bore_6 Bolt_Assembled

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Price $3,096.00

Product Code: AFR-1840

Description

Technical Specs

AFR 260cc LS3 Mongoose Heads feature 100% CNC ported intake, exhaust and chambers using our advanced engineering and flow techniques to produce the ultimate Rectangle Port Head currently available, featuring A356 aluminum castings, titanium retainers and the highest quality components throughout. They are designed for 4.000 or larger bore applications displacing up to 454 cubic inches, operating up to 7000 RPM. Emissions legal for 2008 to 2015 vehicles under CARB #D-250-5. These heads Include new rocker arm stands for use with LS3 1.7 ratio rocker arms. OEM rocker arm stands will not work with these heads. Also, aftermarket rocker arms designed for OEM LS3 applications will not work.

260cc CNC Ported Intake Runners
A356 Aluminum
8mm Bronze Valve guides
5 angle valve job
Precision CNC machining
Multiple spring options

Assembled heads feature:

8mm Bead Lock Valves
PAC Racing Valve Springs
7° Titanium Retainers
LS1 Type 7° bead locks

www.P65Warnings.ca.gov

Description
Item Code	AFR-1840
Vendor	Air Flow Research
Product Type	Cylinder Heads
Product Model	Mongoose
Engine Family	Chevrolet LSx 12°
Weight	72

Included Components

Combustion Chamber	100% CNC Ported
Intake Ports	100% CNC Ported
Exhaust Ports	100% CNC Ported
Valve Job	Competition 5 Angle
Intake Valves	8mm Bead Lock Intake Valve - 2.165 x 5.200 Overall Length
Exhaust Valves	8mm Bead Lock Exhaust Valve - 1.600 x 5.205 Overall Length
Valve Springs	PAC Racing Spring - 1.270 OD - Hydraulic Roller Dual Valve Spring - 155 lbs on seat - .650 maximum lift - 7000-7200 Max RPM
Retainers	7° Manley Chrome Moly - 1.245 O.D x .885 I.D x .655 I.D
Keepers	7° Bead Lock
Rocker Studs
Guide Plates
Valve Seals	.600 OD x .495 ID
Spring Seat Cups	1.380 OD x .570 ID - Hardened
Intake Valve Seat	Ductile Iron - 2.200 OD x 1.750 ID x .375 Deep
Exhaust Valve Seat	Ductile Iron - 1.650 OD x 1.350 ID x .375 Deep
Valve Guides	8 mm Bronze - .502 OD x 2.100 Overall Length

Recommended Components

Intake Gasket	GM or Aftermarket
Exhaust Gasket	GM 12558573
Head Gasket	Cometic 4.160 x .040
Head Bolts	ARP 134-3610
Head Studs	ARP 234-4317
Head Bolt Washers	Manley
Stud Girdle	AFR 6200
Intake Manifold	FAST 92 or 102mm
Spark Plug Starting Range	NGK TR55

Specifications and Features

Material	A356 Aluminum
Intake Port Volume	260cc
Intake Port Dimension	2.610 Height x 1.300 Width - 7/16 Radius
Intake Port Location	Stock
Exhaust Port Volume	95cc
Exhaust Port Dimension	1.540 Height x 1.760 Width
Exhaust Port Location	Stock
Combustion Chamber Volume	69cc
Valve Cover Bolt Pattern	Center Bolt
Valve Angle	12°
Valve Spring Pocket Diameter	1.490 OD
Max Valve Spring Pocket Machining	1.510 OD
Deck Thickness	.750
Minimum Bore Diameter	4.000
Flat Mill	.006 per cc - 62cc Maximum
Angle Mill
Minimum Cross Sectional Area	2.875 sq in
Spark Plug Dimensions	14mm x .750 w/Tapered Seat
CARB EO Number	D-250-5

Flow Chart

Flow Data: cfm @ 28 inches of Water

Lift	.200	.300	.400	.500	.600	.650	.700
Intake	159	234	293	336	366	.377	384
Exhaust	112	158	207	235	248	251	255

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