SEATRA

I was putting in my cams tonight and ran into a problem.
First a little background: t- belt failed and bent all exhaust valves. Machine shop did valve job and replaced exhaust valves with good used ones I had from another head. Engine is out of car and I installed the head last weekend.
Tonight I decided to install the cams. I placed the cylinders at mid cycle and lined up the cams for Nr 1 at TDC. After seating the cams I took a look at the valve seats through the ports in the head. All valves looked good except the 2nd exhaust valve in cylinder 1. It was slightly open. I removed the exhaust cam and followers and looked at the valve stems. All appeared to be the same height. After re-installing the followers I looked at their height too and all appeared the same. Once more I installed the cam with the same results. After taking the cam back off I took a closer look at the exhaust valves of Nr. 1 cylinder. Both appeared to be identically the same as they sat in the head. I re-installed the followers and was trying to figure out how to determine why my one exhaust valve was acting differently than the others. Using finger pressure I pushed down on followers of Nr 4 cyl and noticed that the follower depressed a little less than 1/8 inch. I did this to the rest of the exhaust valve followers and got similar results in all except my problem valve. That follower did not budge.
That brings me to my concern:
I’m pretty sure that if my problem valve follower had the same amount of play that the valve would not be opening slightly at TDC. At this point I think I should I get a new follower for that valve. The cause may be that this follower’s high pressure chamber is filled with enough fluid (locked) at a height that when the cam is installed it slightly opens the 2nd exhaust valve on Nr. 1 cyl. That valves stem height is probably slightly different than the previous one that this follower was operating.
Of course I could be totally off my rocker. What do you guys think?

krazykarl

Move the follower to a different spring temporarily and if the gap you are seeing with the valve moves as well. So you're installing the cams with the TDC marks up even though the crank is at 45 degrees before TDC? The factory instructions make it sound like that is the right process, but I'm struggling to understand how it's supposed to work.

I'm interested in seeing how things go for you as I'll have to go through all of the same stuff in my S2 as I replace a cracked cylinder head.

SEATRA

I'll try to switcherooni tomorow and take a look. I think the crank position at 45 degrees BTDC is the factories way of taking out any chance of piston/valve interference during the cam install. With the crank there you can install those cams in any position and not have a valve contact a piston. Once the cams are in and timing/valve position verified at TDC then the next step would be to slowly rotate the crank clockwise to TDC for timing alignment and belt install. You can position the engine at TDC and lock down the flywheel while you change head and re-install cams too, just make sure you are installing those cams at the TDC position

krazykarl

That does make sense. Manual doesn't go through the reassembly steps in detail so I guess it never clicked for me. Good luck with your project.