MANUFACTURER: Kelford Cams
ENGINE MODEL: 4G63 EVO 8
CAMSHAFT PN#: 8-TX280
SPEC CARD#: 133933
| INTAKE | EXHAUST | |
|---|---|---|
| CAM TIMING EVENTS | ||
| Centerline | 107° | 113° |
| Valve Opening @ 1.0mm | 1.8° BTDC | 47.6° BBDC |
| Valve Opening @ 0.050″ | 1.7° ATDC | 43.9° BBDC |
| Valve Closing @ 1.0mm | 41.4° ABDC | 4.4° BTDC |
| Valve Closing @ 0.050″ | 37.6° ABDC | 7.9° BTDC |
| DURATION | ||
| Actual Duration @ 1.0mm | 222.9° | 223.2° |
| Actual Duration @ 0.050″ | 215.8° | 216.0° |
| Claimed Duration @ 1.0mm | 226.0° | 226.0° |
| PEAK LIFT | ||
| Peak Valve Lift | 11.1mm (0.436″) | 11.1mm (0.436″) |
| Peak Cam Lift | 6.4mm (0.252″) | 6.4mm (0.252″) |
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INFO
Planning to run up to 9,000 RPM? The Kelford 280s were designed to optimize performance from 6,000 to 9,000 RPM. While these “bigger” camshafts trade off some low-end and mid-range performance to the smaller 272 and 264 offerings, they maximize performance from 6,000 RPM and beyond. Simply swapping from OEM to Kelford 280s increased the engine’s peak power output by nearly 30 percent. That’s an additional 125 horsepower at the wheels without any increase in boost pressure. Of course, the more radical nature of the cams will deliver a more race-like idle.
RUNDOWN
583.3 WHP @ 8,400 RPM
410.0 LB-FT @ 6,800 RPM
Peak power checked in at 8,400 RPM while the power curve stays virtually flat from 7,800 RPM until 8,500 RPM. Peak boost was reached at about 4,600 RPM. A flat torque band from 5,800 to 7,800 RPM delivered over 400 lb-ft of torque. Peak torque came in at 6,800 RPM. Highest VE values were recorded at 8,000 RPM. VE figures superior to the stock camshafts at all engine speeds from 4,000 RPM and beyond.
HORSEPOWER |
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| RPM/WHP | FACTORY | KELFORD 280 | GAIN/(LOSS) |
| 2500 | 49.66 | 45.34 | (4.32) |
| 3000 | 82.45 | 61.25 | (21.20) |
| 3500 | 112.31 | 85.92 | (26.39) |
| 4000 | 166.27 | 127.43 | (38.84) |
| 4500 | 281.42 | 251.62 | (29.80) |
| 5000 | 323.28 | 342.6 | 19.32 |
| 5500 | 371.95 | 406.3 | 34.35 |
| 6000 | 399.03 | 456.32 | 57.29 |
| 6500 | 415.72 | 493.58 | 77.86 |
| 7000 | 451.50 | 541.35 | 89.85 |
| 7500 | N/A | 564.27 | N/A |
| 8000 | N/A | 572.2 | N/A |
| 8500 | N/A | 576.2 | N/A |
VOLUMETRIC EFFICIENCY |
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| RPM/% | FACTORY VE | KELFORD 280 | |
| 2500 | 80.5 | 89.0 | |
| 3000 | 88.2 | 95.2 | |
| 3500 | 98.6 | 96.6 | |
| 4000 | 85.9 | 96.8 | |
| 4500 | 85.0 | 97.3 | |
| 5000 | 89.1 | 96.8 | |
| 5500 | 92.1 | 97.7 | |
| 6000 | 88.7 | 99.0 | |
| 6500 | 88.8 | 100.0 | |
| 7000 | 84.9 | 97.0 | |
| 7500 | N/A | 92.1 | |
| 8000 | N/A | 90.0 | |
| 8500 | N/A | 84.2 | |