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Replacement Cam theory for B series engines
.: Publication date 26-Oct-2003 :: Reads: 2874 :: Reviews: 2 :: Print current page :: Print all:.

Here we take a look at various cams available to b16/b18 owners. Before we start looking at the available options, here's a bit of cam theory

Due to the increased lift/duration of replacement cams, the powerband of the car often gets pushed higher and higher. If you're not planning on raising the rev limit of your car, it's best to stick with a stage 1 cam. As the powerband may become out of your reach if you can only reach stock RPM's. For example, for every 20 degrees of duration, expect to push the powerband up by about 1000rpm

Cam Duration = How long the valve stays open for
Cam Lift = The size of the cam lobe determines how far the valve lifts off the seat, higher lift = more torque + peak power

The important thing to remember with VTEC engines is that the tuners often only change the VTEC lobe. This means that low RPM's aren't compromised, but once into the VTEC the aggressive cam profiles will give you all the benefits of uprated cams. Best of both worlds? Perfectly matched to the VTEC engine!

Generally the more aggressive the profile the more benefits you'll see. I'd personally recommend looking into valve springs / retainers if you upgrade cams. Although valve bounce isn't the worst thing in the world it will eventully damage your engine and you'll lose a lot of the benefits of new cams if you're worried all the time about it.

Right enough talk, lets compare the cams. As noted above these are just the profile for the VTEC lobe

STOCK Integra Type R
INTAKE lift 11.5 mm, duration 240 @1mm
EXHAUST lift 10.5mm, duration 235 @1mm

Jun
Type 1
INTAKE lift 10.9 mm, duration 265 @ 1mm
EXHAUST lift 10.0 mm, duration 268 @ 1mm

Type 2
INTAKE lift 12.0 mm, duration 267 @ 1mm
EXHAUST lift 10.9 mm, duration 265 @ 1mm

Type 3
INTAKE lift 12.0 mm, duration 265 @ 1mm
EXHAUST lift 11.5 mm, duration 265 @ 1mm

Type 4
INTAKE lift 12.5 mm, duration 265 @ 1mm
EXHAUST lift 12.5 mm, duration 265 @ 1mm

Skunk2
Stage I
INTAKE lift 11.58 mm, duration 252 @ 1mm
EXHAUST lift 10.8 mm, duration 249 @1mm

Stage II
INTAKE lift 12.3 mm, duration 266 @ 1mm
EXHAUST lift 11.8 mm, duration 262 @ 1mm

Stage III
INTAKE lift 12.8 mm, duration 270 @ 1mm
EXHAUST lift 11.8 mm, duration 279 @ 1mm

Spoon
INTAKE lift 11.53 mm, duration 256 @1mm
EXHAUST lift 11.13 mm, duration 245 @1mm

Toda
Spec A
INTAKE lift 11.6 mm,duration 250 @1mm
EXHAUST lift 11.2mm, duration 240 @1mm

Spec B
INTAKE lift 12 mm, duration 255 @1mm
EXHAUST lift 12mm, duration 245 @1mm

Spec C
INTAKE lift 12.5 mm, duration 255 @1mm
EXHAUST lift 12.5mm, duration 255 @1mm

Spec D
INTAKE lift 12.9 mm, duration - 265 @1mm
EXHAUST lift 11.9 mm, duration - 275 @1mm