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NK Performance and Racing

AFR Mongoose 205CC LS1 CYLINDER HEADS

AFR Mongoose 205CC LS1 CYLINDER HEADS

Regular price $2,712.26 USD
Regular price Sale price $2,712.26 USD
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Spring Upgrade
Exhaust Valve Upgrade

A cost effective choice compared to re-worked factory heads, our 210cc package features fully CNC ported intake and exhaust runners, and combustion chambers. Recommended for street, street/strip and towing applications with displacements up to 383 cubic inches, operating at or below 6300 RPM. A minimum 3.900" bore size is required to clear the supplied 2.020" valve. These heads are legal for use on 2005 and older emissions controlled vehicles, under CARB EO #D-250-4.

*LSX bead locks and aftermarket bead locks are not interchangeable. GM made their bead lock radius and depth different. AFR locks are the same as GM LSX.

Included Components
100% CNC Ported Combustion Chambers
100% CNC Ported Exhaust Ports
100% CNC Ported Intake Ports
Competition 5-angle Valve Job
8mm Bead Lock Intake Valve, 2.020” x 4.900" Overall Valve Length
8mm Bead Lock Exhaust Valve, 1.600” x 4.900" Overall Valve Length
PAC Racing Spring 1.290" OD Hydraulic Roller Dual Valve Spring,
140 lbs on seat, .600" maximum lift, Max RPM 6300-6500, less than 235* duration, upgraded spring #8019 recommended for higher RPM & larger cams
7° Titanium Retainers 1.245" O.D x .885" I.D x .655" I.D
7° Bead Lock Valve Keepers
Viton Valve Seals .600" O.D x .495" I.D
Hardened Valve Spring O.D Locator 1.380" O.D x .570" I.D

 

205cc Competition Flow Chart
  .200 .300 .400 .500 .550 .600
Int 147 214 249 284 296 301
Exh 111 150 209 225 230 233

Test conducted at 28" of water (pressure) on Superflow 1020
Bore Size: 3.900", intake 3/4" radius plate exhaust, 1 3/4" curved pipe


Specifications & Features:
Material
A356 Aluminum
Intake Port Volume
205cc
Intake Port Dimension
3.275"H x 1.120"W x5/16 top 3/8 bottom
Intake Port Location
Stock
Exhaust Port Volume
84cc
Exhaust Port Dimension
1.415" H x 1.710" W
Exhaust Port Location
Stock
Combustion Chamber Size
66cc
Valve Cover Bolt Pattern
Center Bolt
Valve Angle
15°
Valve Spring Pocket Diameter
1.510" O.D
Max Valve Spring Pocket Machining
1.525" O.D
Deck Thickness
.750"
Minimum Bore Diameter
3.900"
Flat Mill
.006" per cc 58cc Maximum
Minimum Cross Sectional Area
2.185 sq. in.
Spark Plug Dimensions
14mm x .750" w/Tapered Seat
CARB E.O.
#D-250-4
 
Recommended Components:
Intake Port Gasket
GM or FAST
Exhaust Port Gasket
GM#12558573
Head Gasket
Cometic 3.930 .040” or AFR #6846
Head Bolts (97-03)
ARP 134-3609 or AFR #6330
Head Studs (97-03)
ARP 234-4110 or AFR #6331
Head Bolts (04+)
ARP 134-3610 or AFR #6334
Head Studs (04+)
ARP 234-4317 or AFR #6335
Head Bolt Washers, Manley
Suggested Manifold
FAST 90mm, 92mm, or 102mm
Spark Plug Starting Range
NGK TR55
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