Big Block Cylinder Heads - Big-Block Cylinder Head Test

TFS Heads
If you look at the flow curves, the TFS and Dart intake-flow numbers virtually overlap throughout the entire flow curve on both the intake and exhaust, which is surprising. Despite this, there are a couple of items that differentiate the TFS heads. First, the TFS intake port has the smallest cross-sectional area of all the aftermarket heads at 2.84 square inches, while the Dart has the largest by a wide margin. The second point is the raised exhaust port, which creates excellent exhaust flow numbers that would probably benefit from a single-pattern camshaft design.

The TFS heads do push the exhaust port up 0.300 inch (left) compared to the stock production big-block Chevy position. This is the main reason that the TFS heads have such strong exhaust-port flow numbers at the higher-valve-lift positions.

The TFS are the second-least expensive aftermarket heads in the test after the Edelbrocks. When you look at the performance per dollar of these heads, they offer outstanding performance for the price.

TFS Oval Port
2.300/1.88 valves
113cc chamber
Intake-port volume: 280 cc
Exhaust port raised 0.300 inch
Intake cross-section: 2.84 sq. in.
PN 41300002

Brodix Heads
The Brodix Race-Rite oval-port heads are an interesting approach. When we first flow-tested these heads, we were impressed with their out-of-the-box performance. Then when the idea for a test came along, Brodix offered a set of CNC-machined chamber versions that we didn't have time to flow-test. According to Brodix's Web site, this chamber mod should be worth roughly 4-5 cfm across the entire valve-lift curve. This also adds another $225 to the price of the heads. This change also bumped the compression, which is why this modification is worthy of consideration. Generally, a CNC chamber is also worth some combustion efficiency that is hard to measure unless we did some kind of back-to-back test on the same set of heads.

The Brodix oval-port head has a very strong intake-port flow curve and a decent exhaust-port curve considering its stock exhaust-port exit location.

The Brodix heads benefited from a CNC-machined combustion chamber that also trimmed the chamber volume down to 110 cc, which helped the compression ratio by over a half point.

The Brodix has a decent exhaust port, but because it is a stock exit-location port, the exhaust-flow numbers are not as strong as the TFS or Darts. This may explain why the Race-Rites benefited at the top a little more from the dual pattern cam. Our only complaint with these heads is that the valve-cover rail is low and spills oil on the headers when we remove the valve covers. Brodix chose to do this to make the heads easier to fit into tight engine compartments faced with clearance problems around A/C compressors and power brake boosters. Overall, this is a great oval-port cylinder head.

Brodix Race-Rite Oval Port
2.25/1.88 valves
Chamber 118 cc (110 cc CNC as tested)
Intake-port volume: 270 cc
Stock exhaust-port location
Intake-port cross-section: 3.08 sq. in.
PN 2061001 (RR BB-O)