RS Aizawa ITB 1.6 - valve stem seals - improvements while in the head ?

[atlex]

I've been doing the lash adjustment and I've two 'direct' specs to work with:

Toda's spec from the cam spec sheet:
IN: 0.20mm
EX: 0.25mm

Mazda's NB2 Solid spec per
IN: 0.21±0.03 mm
EX: 0.31±0.03 mm

( https://trull.org/~alex/pubmirror/ww...e_overhaul.pdf )

As such I've got the intake valves to 0.19 or 0.20mm - and I'm really happy with that.

I'm now redoing up the exhaust valve setup since one was a bit tighter than it ought to be. 0.24mm on one valve - the rest were 0.26. To address the 0.24mm I'll end up taking it closer to the range of the Mazda spec. And I'll treat the Toda 0.25mm as the safe minimum. But for exhaust this seems sensible.

Lash Caps - Tip of the Valve Stem or Tip of the Bucket Post ? Well now...

Supermiata and/or Bill@MiataRoadster suggested the best way to go with the MMD buckets was with 6mm supertech lash caps upside down, the post of the bucket being 5.57mm but I ordered lashcaps from Cat Cams, which only have a 2.5mm skirt and it turns out that with the NB keepers in for the supertech TI retainers, there's legitimately enough clearance to install the lash caps 'normally' on the valve tip. 3.1mm of clearance between tip and top of the keepers with 2.5mm of skirt on the lash caps. Seems the better way to do it. Also no more lash cap randomly pulling out with the bucket, or weird greased lash cap installs.

I'll get to the intake cam, invert the caps, .. measure clearance all over again, and then retime her ,etc.

My only real opponents are wind, rain and time. Mostly wind though.

On a side note..

In my research on valve stems and temperature/expansion coefficients and other similar engines I've found loads of different specs. here are some interesting ones:

A 4age spec that was I: 0.15-0.25mm E 0.20mm-0.30mm - but the valves of the 4age are a bit shorter than the B6 or BP.
zz2 have very similar valve lengths to the B6/BP (5mm difference max) and I: 0.08-0.18mm and E: 0.22-0.32mm specified.

Effectively, the shorter the valve stem the tighter the clearance can be, but it mostly matters for the exhaust side.