Thread: DE valve shim woes

I've been so close to finishing my rebuild, but my low compression numbers have stalled me for a week. I finally got my darn leak-down test kit back (darn neighbors) and it shows horrible numbers. After looking around the cams, I saw the valve shims weren't flush with the retainers, and as such weren't letting the valves seal closed. Now comes the confusion:

The head was rebuilt with new valves. As the FSM so vaguely shows, I measured the distance from the valve retainer flange to the top of the valve stem using a caliper. I had 3.00mm shims on all valves (middle-of-the-road as far as thickness goes), but now I have numbers ranging from 2.22mm to 2.60mm. The FSM table shows the smallest available at 2.800mm.

While I'm confident in these numbers, has anyone ever seen them so small? And more importantly, is there any place I can grab shims that thin? I'm nearly 100% sure they were causing all the leakage, but without the cams on I can't do another leak-down test to feel better.

If you know of a better way to measure the appropriate shim size, that would also be helpful. I measured twice as did my shop partner and we got the same numbers within .02mm (negligible).

Any help is appreciated.

*bump*

I have now read 3 distinctly different ways to find the "proper" shim thickness, and each method gives different measures entirely. I need someone who knows 100% absolutely for sure how to get the right thickness so my valves aren't leaky to let me know the procedure. Nissan techs have given me one way, the FSM has given me another way (makes the most sense), and a fellow owner has given yet another.

Also, I notice the guides come in only one size, so what happens if that guide size is too thick? There was a method that bases the shim size off the guide size, but how can that fix the problem if the guide is so thick it keeps the valve from sealing? You'll get a shim size that will balance the valves, sure, but they'll both be a little open on the compression stroke then. Someone was not thinking when they did these shim designs...
Something sure isn't right here....