SR 20 Series Cylinder Heads/20°

 

 

 

 

 


The new SR 20 from BRODIX is at the cutting edge of conventional big block Chevy compatible technology. This new offering raises the bar to a level that is unreachable by the competition! Inspired by TPSA technology, the SR 20 surpasses any other head in its class by leaps and bounds. Utilizing a .500″ raised 440 cc intake port with a 2.400 intake valve, this head flows an unheard of 507 cfm. The exhaust port flows an amazing 335 cfm through only a 1.800 valve. To allow for the newly designed 95 cc combustion chamber, the intake valve angle of this head has been rolled to 20 degrees. This head requires pistons, valve covers, head studs, shaft rockers, and an intake manifold designed specifically for the SR 20. As always, these heads come standard with all the fine qualities that only BRODIX has to offer.

Package Heads

Facts and Related Components

• PS CB:
Valve Bowls Blended• PS MI:
Match Intake Port to MG 2021

• PS Valve Job:
Competition Valve Job

• Intake Valves:
2.400 x 6.030 o.a.l. – BR 81403

• Exhaust Valves:
1.800 x 5.930 o.a.l. – BR 81080

• Valve Springs:
1.645 Roller Valve Spring – CC 947 or CC 948,
315 lb Closed, 915 lb Open,
2.100 Installed Height,
.850 Maximum Lift (Spring Upgrade)

1.640 Roller Valve Spring – MA 221424,
250 lb Closed, 745 lb Open,
2.050 Installed Height,
.800 Maximum Lift (Spring Upgrade)

• Retainers:
1.625 10° Titanium – MA 23640
1.645 10° Titanium – MA 2001

• Valve Locks:
10° Jumbo – CC 611

• Valve Seals:
11/32 – US VS529V (1.625 Spring)
11/32 – US VS485V (1.645 Spring)

• Torque Heads:
70 ft-lb• Torque Rocker Stands:
40-45 ft-lb

• Intake Gaskets:
BRODIX MG 2021

• Head Gaskets:
4.600 – FEL-PRO 1057, COMETIC C5434

• Exhaust Gaskets:
FEL-PRO 1412

• Valve Cover Gaskets:
BRODIX MG 2020

• Head Studs:
BRODIX SK HS SR 20 For BRODIX Aluminum Block
AR 235-4323 for Cast Iron Block

• Accessory Bolt Holes Are Drilled

• Spark Plug Starting Points:
NGK R5671A-10
For Alcohol
NGK R5671A-9
For Racing Gas

• Spring Pockets:
May Not be Cut Any Larger
or Deeper Than 1.750

• Valve Angle:
20° and 4° Intake
13° and 4° Exhaust

• Angle Milling:
.0066 in Per cc

• Flat Milling:
.0050 in Per cc

• Angle Machining:
Not Available

• Pushrod Slots:
Special

• Stud Girdle:
N/A

• Rocker Arms:
JESEL Or T&D Shaft System –
JESEL KPS 441184, T&D 3142

• Lifters:
Standard

• Pistons:
Special

• Pushrods:
Special Length

• Valve Covers:
BR SR 20 VC

• Intake Manifolds:
BM 2020 (Standard)
BM 2021 (Tall Deck)
• 4.600 Minimum Bore

Flow Chart cfm @ 28″ H20

Part Number Valve Size 0.200 0.300 0.400 0.500 0.600 0.700 0.800 0.900
BP SR 20 2.400 Intake 50° 161 242 326 399 455 487 498 507
1.800 Exhaust 55° 129 176 216 254 291 308 326 335

Basic Easy Order Numbers

Part# Easy
Order #
Port
Vol.
Cham.
Vol.
Int/Ext
Valve
Spring Seat
Pressure
Spring
Diam.
Ret.
ST/TI
Per
BP SR 20 Bare
2208000 440 95 2.400 / 1.800       1
BP SR 20 Pkg
2208100 440 95 2.400 / 1.880 315 1.645 TI 1