Dropped a cylinder - Help
 

Begi S4, MS3, 99 head, 94 block, wiseco pistons, eagle rods, yada yada.. "Well built"

Was cruising along, and noticed a "clack" at mid-range load. Babied the car home. Idle sounded fine, minus a weird-ish sucking sound (sorta like.. "fwump"). With the car at idle, pulled the spark plug wires - cylinder 1 made no noticeable difference at idle. Discovered a vacuum port cap had also disintegrated closest to the 1st cylinder runner. Ran a compression test -

Dry: 100 150 155 165
Wet: 115 169 171 180

Fearful of a cylinder 1 lean condition causing that destroyed an exhaust valve, I pulled the head. To my surprise, the exhaust valves look "okay" to my untrained eye. Roughly 20k miles since I've gone turbo. I inspected the valve and seat as well as I could without pulling the valve, cleaned the carbon off the piston heads and inspected the walls - no lip at TDC, no major gouges in the cylinder wall - nothing I could catch my fingernail with anyway.

I filled the combustion chamber with some rubbing alcohol...

https://www.miataturbo.net/attachmen...ine=1350245019

It started slowly leaking out of the intake port (hard to picture - but you can see the oil pool.. should've tried with some food dye..) I doublechecked the seat and valve as best I could without pulling them and still can't find damage.

So... Here's some more pictures of my combustion chambers. Can anyone provide me some feedback/thoughts for low compression? The combustion chambers are still a little oily from the wet test, sparkplugs looked to be OK - some brown specks on cylinder 1, but it looked more like soot than detonation.

https://www.miataturbo.net/attachmen...ine=1350245019

https://lh5.googleusercontent.com/-A...013_201724.jpg

https://lh5.googleusercontent.com/-v...013_201710.jpg

https://lh3.googleusercontent.com/-H...013_201720.jpg

Since the head is off and I'm probably gonna need work on it anyway, I'm considering ponying up for Supertech +1mm / exhaust valves.. just weighing the benefits vs cost..

Took it over to my buddies tonight, and we figured some of it out:

1. Valve lash is all whacky. Can't fit a feeler gauge on some lobes. D0h.
2. Guides are feeling loose, a bit of slop present.
3. Uneven wear mark on one of the valve / valve seats. Probably from the slop.

Time for a rebuild.