Another small piece of the puzzle. If this one works it is going to be my best idea yet! Lol
So the 80 uses a shim on bucket design. Where under the cam you have a bucket that sits on top of the valve and spring and then you adjust lash by adding a thin shim to the top of that bucket.
Something similar to this.
In situations where you have increased the spring pressure, or increased the lift, or increased the lift speed of the cam, or increased the RPM's, you have the potential of that shim being pushed off the bucket because of spring bounce and banging around inside the head causing all kinds of problems.
One way to get around this is to do a shim under bucket design where you place the shim inside the bucket and it spaces the bucket up to the cam. The only problem with this is if the bucket wasn't designed to wear against the cam you get accelerated wear, metal flake, or if the bucket has lips to retain the shim they catch the cam.
This had been figured out 9+ years ago on the Supra's using later MR2 buckets. In the Supra it also reduces a lot of weight from the valve train. But obviously the MR2 buckets are way too small for the 1FZ.
So the Nissan series of engines including the GT-R, use a shimless bucket for the cam to ride on and compress the spring and move the valve. They accomplish this by offering many different sizes of "lifter-valves" these have the "shim" built into the underside of the bucket.
I know I am probably going to have to mill the underside to get it to match the valve lash perfectly, but you get a shimless system, a hardened bucket that even has a DLC (Diamomd Like Coating) on the face to reduce friction and eleminate wear!!
I won't know for certain if they will work until the Ferrea stuff gets here but that is supposed to be Monday.
Until then check these bad boys out! Lol
View attachment 1066496
View attachment 1066497