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Originally Posted by Cloudsurfer
These engines are actually very tolerant of small timing errors, and I'm sure that Insite is within the allowable limits, but it's not how I'd do it.
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cloudsurfer: i initially planned only to CHECK if i could set timing without the tools. i actually used metrology shots to index the cams to the heads. after rotating the crank, i shot them again to make sure the cam hadn't turned. they didn't move even a sliver. setting TDC compression on bank 1 & TDC exhaust for bank 2 ensures that the cams are 'off lobe' and no valve springs are creating a polar moment. in this position, the cams actually 'WANT' to center on the timing marks. in fact, if you rotate the cams like 20deg one direction or the other, they will rotate back!
that having been said, it's pretty easy to eyeball the groove in the cams & the seam between the head & valve cover. the only concern for me at that point was whether the cams would move at all when i rotated the crank. they don't.
this is the only car i've worked on where the factory tries to get you to use all these holding fixtures. every other car involves us simply eyeballing the crank to a matchmark & doing the same thing w/ the camshaft. i find it hard to believe that only the porsche would be affected by thousandths of a degree here.
in fact, before i timed my motor, both banks were visibly off. jake says he sees them this way ALL THE TIME and that many are set improperly from the factory. IMO, the chains stretch over the engine life cycle, too.
it's not important to be PERFECT here, merely very good.