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Registered
Join Date: Jun 2004
Location: Rio Rancho, New Mexico
Posts: 1,325
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Hi James,
I get most of this info from Bruce Andersons "Porsche 911 Performance Handbook"
For instance a 2.0L '69E with MFI runs the same cam as the '70/'71 911E, 2.2L.
That is the intake opens at 29* BTDC, closes at 39* ABDC, for a total duration of 248 degrees. This as measured from 1mm open to 1mm closed.
A 2.0L '69S motor is hotter. the intake opens at 38* BTDC and closes at 50* ATDC, for 268 degree duration.
I would recommend Bruce Anderson's book, as well as Paul Frere's "Porsche 911 Story". In addition to Wayne's "101 Projects", each offers something just a little different.
Most of the early engines were timed with a degree wheel before using a dial indicator and going with the 1mm open spec.
If I don't have the timing spec's in mm's, I just use a degree wheel.
Since both cams perform well, I'd suspect the motor kept the cam that came with it. But, you really don't know without looking.
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DOUG
'76 911S 2.7, webers, solex cams, JE pistons, '74 exhaust, 23 & 28 torsion bars, 930 calipers & rotors, Hoosiers on 8's & 9's.
'85 911 Carrera, stock, just painted, Orient Red
Last edited by 2.7RACER; 05-11-2007 at 10:55 PM..
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