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Oval Port Big-Block Chevy Cylinder Heads - The Big O

The best way to illustrate the power potential of performance cylinder heads is on the dyno.

By Richard Holdener, Photography by The Author

Test 7: Procomp Electronics

Procomp Electronics has made its name by providing affordable performance. Its BBC oval-port heads qualify on both counts, as the as-cast aluminum heads maximized airflow and minimized cost. The second of the true as-cast heads, the oval-ports from Procomp Electronics featured no porting or CNC chambers and instead relied on the as-cast port shape to maximize flow. With a peak flow number of 346 cfm, the Procomp Electronics casts had plenty of potential, but they were hampered by the largest combustion chamber of the group. The 121cc chambers dropped the static compression 1 full point compared to the other competitors. If each point is indeed worth an extra 3-4 percent in power, a comparable compression ratio would put these heads right in the hunt in terms of power. But equipped with the 121cc heads, the 468 produced 555 hp and 527 lb-ft of torque. Since compression hurts power everywhere, the average numbers dropped to 471.1 hp and 506.1 lb-ft of torque. Though down on power, Procomp Electronics should have no trouble selling these at a retail price of just over $1,000 a pair.

  • Notes: As cast, no porting
  • Retail Price- $1,095 (with spring upgrade)
  • Intake Valve Size-2.25
  • Exhaust Valve Size-1.88
  • Intake port vol-311 cc
  • Chamber Volume-121 cc
  • Peak Power-555 hp @ 6,200 rpm
  • Peak Torque-557 lb-ft @ 5,200 rpm
  • Avg HP [3,000-6,500]-471.1 hp
  • Avg TQ [3,000-6,500]-506.2 lb-ft
  • Tq @ 4,000 RPM-507.6 lb-ft

Flow Data: CFM @ 28-ins

LiftInEX
.0503629
.1007761
.200140126
.300214174
.400276210
.500314241
.600331264
.700346284

Test 8: Trick Flow Specialities 280

When talk turns to performance cylinder heads, naturally Trick Flow Specialties has to be included. It stepped up for this test with a set of its PowerOval 280s. As indicated by the name, the PowerOvals combined 280cc intake ports with a 2.19/1.88 valve combination. Despite choosing the smaller intake valve (2.19 vs. 2.25), the PowerOval heads offered plenty of flow. Though the heads featured as-cast ports and chambers, the intake port did receive a minor port match. Even without the aide of CNC porting, the PowerOval heads offered flow numbers of 337 cfm on the intake and 261 cfm on the exhaust. These flow numbers translated into a peak power output of 576 hp and 544 lb-ft. The PowerOval heads offered a broad torque curve, bettering 515 lb-ft from 3,800 rpm to 5,700 rpm. In terms of average numbers, the TFS heads produced 485.7 hp and 521.7 lb-ft of torque and managed 517.8 lb-ft of torque at 4,000 rpm. The PowerOvals are affordably priced at under $2,000 assembled and ready to run.

  • Notes: As cast no ports and chambers
  • Retail Price- $1,849 (with spring upgrade)
  • Intake Valve Size-2.19
  • Exhaust Valve Size-1.88
  • Intake port vol-279 cc
  • Chamber Volume-113 cc
  • Peak Power-576 hp @ 6,100 rpm
  • Peak Torque-544 lb-ft @ 5,200 rpm
  • Avg HP [3,500-6,500]-485.7 hp
  • Avg TQ [3,500-6,500]-521.7 lb-ft
  • Tq @ 4,000 RPM-517.8 lb-ft

Flow Data: CFM @ 28-ins

LiftInEX
.0503230
.1006762
.200143122
.300212160
.400266189
.500302221
.600328244
.700337261

By Richard Holdener
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