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-   -   Intake cyl 1 & 4 opening separation in Crk degrees (http://forums.pelicanparts.com/911-engine-rebuilding-forum/643084-intake-cyl-1-4-opening-separation-crk-degrees.html)

HKZ Bob 02-08-2012 11:27 PM

Dear all


Is this timing chart with ABDC BBDC correct?

I am not so familiar with After Botoom Dead Center
and Before Bottom Dead Center.

Intake opens 12° later than S cam but is 11° longer open:

Exhaust: opens 11° later & closes 37° later



http://forums.pelicanparts.com/uploa...1328775664.jpg

Eagledriver 02-09-2012 05:13 PM

BDC is when the piston is at the bottom of it's travel. It occurs 180 degrees of crankshaft rotation after TDC. Typically the cam duration is specified at some level of valve lift, not when the valve first opens or closes. I don't know what that level of valve lift is and I do know that it varies with the source of the cams and the source of the spec book. It looks like you have enough information to time your cams.

-Andy

HKZ Bob 02-12-2012 02:00 AM

Dear all, now you can see what profile I have on Cylinder 4.

They are stamped as S.

I guess I am in trouble with a mixed cams in my engine.

Does Waynes data is listing the lift at 0mm or 1 mm lift.

http://forums.pelicanparts.com/uploa...1329042507.jpg

I have my overlapping @ 4mm

exhaust cyl. 4 opens (1mm lift) 41° BBDC
exhaust cyl. 4 closes (1mm lift) 9° ATDC

For an S cam it closes to early!



Accordings Waynes book this is likely a 911T Camshaft from 65 to 68.
or 68 911


Now the intake
Intake opens (1mm lift ) 38° BTDC
intale closes 81mm lift 44° ABDC
It has a lift about 11,15 mm

Inake is close to an 911 S profile. Lift on S is 11,55mm.

So someone modified the exhaust profile?
Let me know your thoughts.

BR
bob
I

HKZ Bob 02-12-2012 02:08 AM

and here both cams in one diagramm.

http://forums.pelicanparts.com/uploa...1329044895.jpg


What a disaster!!!!!

Weekend frustration is programmed.


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