DSPORT Magazine technical showcase editorial on EVO 4G63 camshaft options

MANUFACTURER: Cosworth Engineering
ENGINE MODEL: 4G63 EVO 8
CAMSHAFT PN#: KK3805
SPEC CARD#: N/A

INTAKE EXHAUST
CAM TIMING EVENTS
Centerline 107° 113°
Valve Opening @ 1.0mm 4.7° ATDC 49.2° BBDC
Valve Opening @ 0.050″ 8.3° ATDC 45.3° BBDC
Valve Closing @ 1.0mm 38.7° ABDC 8.7° BTDC
Valve Closing @ 0.050″ 34.7° ABDC 12.9° BTDC
DURATION
Actual Duration @ 1.0mm 214.0° 220.5°
Actual Duration @ 0.050″ 206.4° 212.4°
Claimed Duration @ 1.0mm 214.5° 213.5°
PEAK LIFT
Peak Valve Lift 11.1mm (0.436″) 10.3mm (0.404″)
Peak Cam Lift 6.5mm (0.252″) 5.9mm (0.233″)

Manufacturer’s Pitch

Cosworth has been engineering camshafts for nearly 50 years. That coupled with years of innovative multi valve cylinder head design ensures our camshaft designs are the most efficient in providing maximum usable power across the widest power band. Each cam is ground from a new billet and finished using the same procedures we use in our extreme level race engines. Cosworth camshafts are the perfect compliment to our CNC Ported Big Valve Cylinder heads. Our cams are profiled to increase boost response thereby increasing engine torque and power.

INFO

The milder of the two Cosworth offerings, the M1s from Cosworth delivered a 20 percent increase in peak power over the factory bumpsticks. This camshaft set, touted as “264s” by Cosworth, raises peak power RPM to 8,300 RPM and requires a valve spring upgrade. Despite a slightly lopey idle, streetability of the vehicle is hardly affected. Past 4,000 RPM, the Cosworth M1 camshaft set made significant power gains. The loss in power from 3,000 to 4,000 may be attributed to the larger-than-factory AMS intake manifold with big runners.


RUNDOWN

DSPORT Magazine technical showcase editorial on EVO 4G63 camshaft optionsDSPORT Magazine technical showcase editorial on EVO 4G63 camshaft options

544.74 WHP @ 8,300 RPM
409.05 LB-FT @ 6,000 RPM

Peak power checked in at 8,300 RPM, as the power curve flattened out from 7,000 to 8,500 RPM. Peak boost was reached at roughly 4,400 RPM. The torque curve remains flat from 5,300 to 7,200 RPM and tapers off slightly higher in the power band. Maximum torque of nearly 410 lb-ft was reached at 6,000 RPM. Highest VE values were recorded at 6,500 RPM, just barely reaching the 100.0 mark. Superior VE figures superior to the factory camshafts were recorded from 4,000 to 8,500 RPM.

HORSEPOWER

RPM/WHP FACTORY COSWORTH M1 GAIN/(LOSS)
2500 49.66 53.02 3.36
3000 82.45 63.96 (18.49)
3500 112.31 100.38 (11.93)
4000 166.27 147.96 (18.31)
4500 281.42 288.02 6.60
5000 323.28 352.76 29.48
5500 371.95 411.55 39.60
6000 399.03 459.21 60.18
6500 415.72 490.04 74.32
7000 451.50 520.92 69.42
7500 N/A 525.30 N/A
8000 N/A 534.15 N/A
8500 N/A 533.94 N/A

VOLUMETRIC EFFICIENCY

RPM/% FACTORY VE COSWORTH M1
2500 80.5 89.3
3000 88.2 95.3
3500 98.6 96.5
4000 85.9 97.0
4500 85.0 96.8
5000 89.1 96.9
5500 92.1 97.7
6000 88.7 99.0
6500 88.8 100.0
7000 84.9 97.3
7500 N/A 92.0
8000 N/A 90.0
8500 N/A 84.0
Share.

Comments are closed.