I’m reading up on the service manual and I see the specs calls for

Intake: 0.08 – 0.12 mm
Exhaust: 0.16 – 0.20 mm

What are the differences if I were to adjust my intake to .12 mm as opposed to .08 mm or vice versa? Same question goes for the exhaust valves? Will running tighter clearances give me less power? I have a stock B18B in my DD and I noticed its kinda loud. Any preference?

 

if you adjust your valve clearances to the loose side of the spec, they may more quickly loosen up to a distance outside the spec. i just checked mine at 120k and they are all on the small side, intake and exhaust. it seems they haven't moved since the assembly at all. since these aren't bucket over shim valves where the shims can wear down and cause your valve clearances to become too tight, the concern is the valves working their way too loose.

 

I usually do my adjustments on the tighter side of specs...

Thats my personal preference. You will not see significant power being gained from an adjustment, so just make sure you are within spec and you will be ok.