Damnit, is this true? If it is, then that theory in the back of my mind was correct and the cam is 180 out. At Z1 the rockers on cylinder 4 are loose, and not compressed. I may have to add this to the "stupidest thing you have done to your Porsche" forum.

As I said, set to Z1 as though were going to adjust number 1 cylinder valves ...in which the valves should be "loose", then go over to the passenger side bank and verify that number four is tight...not loose.

I'm pretty sure that's one way to check. Maybe another member can verify...

I don't think just arbitrarily setting the engine to Z1 is good enough. You have to determine which cylinder's valves would actually be in a postion to adjust...thus you'll need to remove the valve coveres from both sides of the engine.

When #1 fires, it as at the nominal top of the stroke, between Compression and Power. Ay this instant, #4 should be at the top between Exhaust and Intake, Unless you have zero overlap in the cams, or your valve lash is set incorrectly, you shouldn't have the valve lash you describe.

Try taking the valve covers off, and watching the valve motions on #1 and #4 for a few rotations of the crank, to see what's what. Just follow along with the I-C-P-E routine a bit, and it will become apparent if you timed the cams wrong.

Pat

Pop a link to this thread on the rebuilding forum. Those guys do cam timing in their sleep, so you'll have an answer by morning.