205cc LSX Mongoose Street Aluminum Cylinder Head
The Small Port, High Velocity Torque Monster
For the ultimate high performance street LS1/LS2/LS6 aluminum cylinder head AFR’s all
new 205cc emission legal E/O # D250-4 are your only choice. Specifically
designed for 1997 to present Gen-3 Chevy Corvettes, Camaros, and
trucks. AFR’s LSX cylinder head offers unmatched flow performance (298
CFM at .600lift) and features 2.020 intake and 1.600 exhaust valves
with AFR’s iron ductile interlocking valve seats. With only
205cc port volume (same as stock LS1 head) this is an incredible
70 CFM increase over stock casting, creating unbelievable port velocity
and performance. Our 205cc cylinder head is ideal for normally aspirated 346C.I.
to 396C.I. It is available with 66cc combustion chambers.
AFR’s LSX is a direct bolt on, no special parts required (see footnotes here). Structural features
like Air Flow Research’s trademark 3/4” thick head deck,
a must for blown and nitrous applications, reinforced rocker stud
bosses, and thick wall runners provide unparalleled durability.
An exclusive new modern combustion chamber design with double quench
pad area helps the LSX generate huge low and mid lift airflow numbers.
If you need a snake charmer for that pesky neighborhood “Cobra
Mustang” look no further.
Note:
Hydraulic roller cams in "LS" Gen III engines typcially experience valve
float at 6600-6800 RPM's. If you are using aftermarket rocker arms valve float will become prominent and AFR highly recommends upgrading to our #8019 spring. If you plan on running over .600 gross valve
lift and/or 6600 RPM, AFR suggests you upgrade your springs to AFR part #8019.
Our upgrade spring has higher seat and open pressures (155/410+) to better
reduce the risk of valve float in more aggressive applications.
FYI: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.
205cc LSX Aluminum Cylinder Head Flow Chart
Tested on 3.900 Bore
Basic Package Components
100% CNC Ported Combustion Chambers
100% CNC Ported Exhaust Ports
100% CNC Ported Intake Ports
3-angle Radiused Valve Job
AFR #7207
Bead Lock Intake Valve, 2.020” standard length
AFR #7228
Bead Lock Exhaust Valve, 1.600” staindard length
AFR #8017
1.290” OD Hydraulic Valve Spring with dampener, 135 lbs. on seat, .600: maximum lift
Specifications, Features, and Optional Supporting Components
11mm ARP 70ft. lbs. w/ Moly
Head Torque
8mm 23ft. lbs. w/ Moly
Head Torque
AFR #6859 or GM#12558573
Exhaust Port Gasket Fel-Pro #1440
205cc
Intake Port Volume
84cc
Exhaust Port Volume
Jesel or TD Shaft Mount
LS6
Suggested Manifold
FAST TPIS
Suggested Manifold
AC 41-974 Platinum
Spark Plug Starting Range
66cc or 76cc
Combustion Chambers
1.250
Spring Pocket
Stock
Valve Spacing
Stock
Rocker Arms
Stock
Valve Angle
.006" per cc
Flat Mill (milling options available)
Note: Milling head deck will affect flow numbers. |
