911 valve adjusters in 1.8 rockers, any advantage for offset installation? |
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911 valve adjusters in 1.8 rockers, any advantage for offset installation? |
Mueller |
Sep 25 2016, 10:24 PM
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#1
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914 Freak! Group: Members Posts: 17,146 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None |
I thought I bought a 1.7 from a member and it looks like it is really a 1.8 that had 1.7 D-Jet installed on it.
So the rockers have the larger 10mm holes instead of the 8mm 1.7 rockers so my 911 swivel feet adjusters won't work as is. Would there be any benefit to ensure the valve tip to adjuster foot is perfectly aligned or should it be offset a tad more one way or another? |
jcd914 |
Sep 26 2016, 12:16 AM
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#2
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Advanced Member Group: Members Posts: 2,081 Joined: 7-February 08 From: Sacramento, CA Member No.: 8,684 Region Association: Northern California |
They are offset from the centerline of the valve so the the wiping action causes the valve to rotate slightly, this helps keep the contact surfaces of the valve to valve seat clean of carbon and reduces hot spots on the valve and valve seat.
There was a member here that had shimmed or machined the rockers to line up dead center but I don't remember who. How much difference it would make, I don't know and it could be years before any difference was noticed. Jim |
porschetub |
Sep 26 2016, 02:28 AM
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#3
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Advanced Member Group: Members Posts: 4,696 Joined: 25-July 15 From: New Zealand Member No.: 18,995 Region Association: None |
They are offset from the centerline of the valve so the the wiping action causes the valve to rotate slightly, this helps keep the contact surfaces of the valve to valve seat clean of carbon and reduces hot spots on the valve and valve seat. There was a member here that had shimmed or machined the rockers to line up dead center but I don't remember who. How much difference it would make, I don't know and it could be years before any difference was noticed. Jim Correct and well explained, but shimming is a bandage machining the rocker the arms is the cure,do not change the rocker arm offset to the top of the valve stem. I'am running the original CB performance ones in my speedster plastic copy with an 1.8 euro carb motor ,I machined the arms and it works fine with arms from an 1.7. Appears these kits are now poorly made (samba info) and to go to 911 ones is very expensive. You can still maybe buy the original adjustment screws but I don't know of a source. |
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