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dtw dtw is offline
Join Date: Dec 1999
Location: Raleigh, NC, USA
Posts: 7,838
Here's what I'd do:

Install your dial gauge on the left bank/#1. Ensure left-side chain is tensioned up, or clamp the idler arm to the top of the chain housing to tighten the chain. With your rockers backed off on the right bank (don't want to ding a valve while messing around over on the left bank), turn the engine to Z1/TDC overlap on #1. Take a reading of the cam timing on the left bank. Ensure both that you can repeat the measurement (by turning the engine thru 720' a couple times) and that the measurement is within specs. Now time the right bank as closely as possible to the reading you took on the left. Don't sweat it if you use different techniques to tension the chain left vs. right; on the stock DME cam a minor variance is not going to have any impact.

Most first-timers seem to get confused about the orientation of the cams during the timing process. Here's a way to improve the process above if it makes sense to you. With both chain covers off, turn the engine to Z1 and make sure the dot or '911' (or other PN stamping on the snout of the cam) on the left-side cam is pointing up. If pointing down, turn the crank through another 360. Now turn the right-side cam by hand (with rockers backed off) to the same orientation - markings up, so it is the same as the left. Now keep this rough timing by pinning the cam to the sprocket with the dowel pin and hand-torquing the bolt. While taking measurements on the left, the right will stay rough-timed. After finishing taking measurements on the left, set your dial gauge on the right and turn through 360 on the crank. You'll be on-cam on the right bank/#4, and ready to fine-tune timing.

Exercise extreme caution with the woodruff key and dowel pin, they WILL throw themselves down the chain case at the slightest opportunity. Often a good idea to stuff a clean shop towel down there. Saved my bacon on my latest build.

Is your left-side cam housing ok? Hate to see you going through this again in a few months on the left bank.
'72 911T Silver
'01 996tt Lapis Blue
Lots of BMWs
Old 06-17-2008, 10:36 AM
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