Engine/Transmission (1998.5 - 2002) Performance after valve adjustment

[DNewell]

Well, I did the valve lash adjustment last night on the truck. Not a bad job, but boy, #6 is a real joy to get at... My question is this, of those who know: what should I see for performance after adjusting the lash on the valves to constant figures? I didn't check the before numbers, but I set the intake at . 20mm and the exhaust at . 50mm. I got a lot of conflicting information in regards to what numbers to run, with some people running tight at . 08mm on intake and . 18mm on exhaust.

All I know is that i did adjust the lash tighter, I'd have to say the intake was more like . 3-. 4mm and the exhaust was around . 7-. 8. I noticed before that my truck seemed to have more seat of the pants power at the 3k rpm range, and was a little doggy in the lower RPM range. Now the truck falls on its face at around 3k and seems to have more low end grunt. Is this typical?

I know that we don't run our trucks in the 3k rpm range much, except for when we're playing, but are my results typical? Just curious.



Also, as a side note, will I see a slight increase in EGT's after tightening up the valves? I only ask this because it seems that at 60mph on the freeway this morning, my EGT's were around 70-80 warmer. They are normally at around 600 and were more like around 670-680. Anyone else experience this? Thanks!

 

[JFaughn]

I'm still in the inch world , so had to check , your a little tight .
unless there is a significant change in adjustment , the thing I've noticed the most over the yrs is a smother idle .
Here's a link for info .
CumminsDatabase.com :: B Series Valve Clearance Adjustment

 

[DNewell]

I checked that database, and the new specs that I used are within recommended guidelines. What I don't understand is why some people run it as tight as . 08mm and . 18mm on intake and exhaust respectively. Wouldn't these people be risking buring a valve? I figured I'd run on the loose side to ensure that nothing got burned, especially since I run a Van Aaken box. Not that the box is all that powerful, but I did learn that with additional fueling, you don't want to run so tight because you do run the risk of burning a valve. Not what I want to do to the truck...