I went in and did the valve lash adjustment on my d15b6 (250k+ mi) and I noticed that they were all too tight.

I've done it before on another Honda but I didn't pay attention to if the clearances were too tight or loose.

Isn't the valve lash clearance supposed to increase with mileage?

before anyone asks, yes this was performed while the engine was cold.

 

One would think that the clearances would increase, but on engines like the B20, they like to get tighter. I think I read something about the valve seats tend to sink into the head with B20's. As for your engine's valves, who knows. I'd just adjust them and move on. What else can you do?

 

I just want to understand it better. Like you said, the b20's tend to get tighter. This may be the case with the d15b6.

 

Possibly. I found the info below on vw head porting site. Maybe some of it can relate.

"As valves and seats wear, they tend to sink lower into the seats creating seating surface mismatches and valve shrouding (partial blockage or restriction caused by objects in close proximity of the valve seat; imagine having the valve having to lift itself out of a deep crater before it can start to flow). Wide seating surfaces tend to last a little longer when the valves sink under wear."

 

if done too tight they may not increase in clearance with milage jus put them in spec and use the firing order order and u should be good

 

no no, I did NOT adjust them to tighter spec. I FOUND them out of spec on the lower range, so they were mostly all too tight to begin with. The car is back in mid-range spec and drives great (no longer sounds like a diesel LOL). Easiest valve adjustment ever, so glad it only has 8!

What I'm looking for is if anyone else has noticed the gap to be too tight when they go in to adjust them.

 

Ive done 3 D15B2s and 2 D16Z6s now and they all have been too loose when I checked them.

Were the adjusted properly in the past? Maybe they were even tighter to start with? Doesn't seem likely, it's just a thought.

 

I thought about it but I really don't see how anyone could set them that tight.