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Xrenoder
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Вот у себя нашел, выжимку по-моему с насиока, ссылка и автор не сохранились - прости меня, англоязычный субодруг!
Both on and off durations are estimated over by 10-12 degrees of cam degrees. Crank degrees are 2x of cam degrees (cam shafts spin at half rpm). So, in this case, a 256 degree cam measured C-C becomes at 208-216 degree cam.
This corresponds well to the numbers that Clark mentioned about the US WRX cam.(216) and the numbers Cobb says (208).
The factory manual specs them at 240 degrees duration, so I speculate they might be using some other standard lift height (perhaps the lif height that equals the valve seat depth?)
So now that we have an approxmiate conversion what what I measure to the more standard .050" lift method, let's build of table of what I measured.
US WRX Cams:
Intake: 256 -> 208-216 degrees duration
Exhaust: 256 -> 208-216 degrees duration
US STI 2.5 Cams (Not measured, but factory manuals indicate these cams have the same duration as the US WRX ones)
Intake: 256 -> 208-216 degrees duration
Exhaust: 256 -> 208-216 degrees duration
JDM Version 7 STI Cams
Intake: 274 -> 226-232 degrees duration
Exhaust: 274 -> 226-232 degrees duration
JDM Version 7 STI RA Spec C Cams
Intake: 274 -> 226-232 degrees duration
Exhaust: 274 -> 226-232 degrees duration
....................................
Now let's look at lift: These are measurements I made tonight with the Cams I have, plus what I got from the service manuals:
Stock WRX:
Intake ServiceManual=9.25mm Measured=9.25mm
Exhaust ServiceManaul=9.15mm Measured=9.20mm
JDM STI:
Intake ServiceManual=8.25mm, Measured=8.25
Exhaust ServiceManual=8.6mm, Measured=N/A
JDM STI RA Spec C
Intake ServiceManual=NA, Measured=8.9mm
Exhaust ServiceManual=NA, Measured=9.6mm
US STI 2.5
Intake ServiceManual=9.55mm, Measured=NA
Exhaust ServiceManual=9.75mm, Measured=NA
I have been told by a couple of sources that the RA cams have 10mm lift, but I measured two different CAMs tonight.. And one was a brand new still in the Subarubox CAM direct from Japan for the STI RA Spec C motor. Sure enough the RA has more lift then the regular STI, but both have less then the US WRX and US WRX STI. Of course both STI Cams have much more duration then both the WRX and US WRX STI.
Both on and off durations are estimated over by 10-12 degrees of cam degrees. Crank degrees are 2x of cam degrees (cam shafts spin at half rpm). So, in this case, a 256 degree cam measured C-C becomes at 208-216 degree cam.
This corresponds well to the numbers that Clark mentioned about the US WRX cam.(216) and the numbers Cobb says (208).
The factory manual specs them at 240 degrees duration, so I speculate they might be using some other standard lift height (perhaps the lif height that equals the valve seat depth?)
So now that we have an approxmiate conversion what what I measure to the more standard .050" lift method, let's build of table of what I measured.
US WRX Cams:
Intake: 256 -> 208-216 degrees duration
Exhaust: 256 -> 208-216 degrees duration
US STI 2.5 Cams (Not measured, but factory manuals indicate these cams have the same duration as the US WRX ones)
Intake: 256 -> 208-216 degrees duration
Exhaust: 256 -> 208-216 degrees duration
JDM Version 7 STI Cams
Intake: 274 -> 226-232 degrees duration
Exhaust: 274 -> 226-232 degrees duration
JDM Version 7 STI RA Spec C Cams
Intake: 274 -> 226-232 degrees duration
Exhaust: 274 -> 226-232 degrees duration
....................................
Now let's look at lift: These are measurements I made tonight with the Cams I have, plus what I got from the service manuals:
Stock WRX:
Intake ServiceManual=9.25mm Measured=9.25mm
Exhaust ServiceManaul=9.15mm Measured=9.20mm
JDM STI:
Intake ServiceManual=8.25mm, Measured=8.25
Exhaust ServiceManual=8.6mm, Measured=N/A
JDM STI RA Spec C
Intake ServiceManual=NA, Measured=8.9mm
Exhaust ServiceManual=NA, Measured=9.6mm
US STI 2.5
Intake ServiceManual=9.55mm, Measured=NA
Exhaust ServiceManual=9.75mm, Measured=NA
I have been told by a couple of sources that the RA cams have 10mm lift, but I measured two different CAMs tonight.. And one was a brand new still in the Subarubox CAM direct from Japan for the STI RA Spec C motor. Sure enough the RA has more lift then the regular STI, but both have less then the US WRX and US WRX STI. Of course both STI Cams have much more duration then both the WRX and US WRX STI.