Did a Valve Adjustment

[Vaughn MacKenzie]

Well I checked my lash and decided to tweak all 12 rockers last night. The exhausts were all around . 022" and Intakes about . 012" I decided to tighten them up a bit and went for . 018" exhaust and 0. 08" Intake. Hopefully that's not too tight. If I were cranking the power or towing heavy I should probably back them off to 10 and 20 thousandths.



One thing I noticed is they were very very close to each other, more consistent than any of my previous trucks or any others I have checked valve lash on. Maybe with tightening emissions Cummins has tightened up their tolerances.



Vaughn

 

[banshee]

All the valves are set by a giant robot, so they should all be very close. The whole assembly line in Columbus is full of machines that do everything at once... it's a work of art!



John

 

[draymorris]

How many miles do you have on your truck?



Thanks

 

[Crunch]

Originally posted by Vaughn MacKenzie

Well I checked my lash and decided to tweak all 12 rockers last night. The exhausts were all around . 022" and Intakes about . 012" I decided to tighten them up a bit and went for . 018" exhaust and 0. 08" Intake.

I thought valves were supposed to be self-adjusting on modern engines. Is that not the case?

 

[nickleinonen]

Originally posted by Crunch

I thought valves were supposed to be self-adjusting on modern engines. Is that not the case?

that works if you have hydraulic lifters. if you have solid roller lifters, then it's manual adjustment all the way...

 

[Vaughn MacKenzie]

I have 23,000 miles daymorris. Crunch our trucks have good ol' mechanical lifters, which I MUCH prefer, since you do not have to worry about lifters going flat over time.



I checked mine since I had the valve cover off anyway as well as the lower girdle so it was easy to get to them. Since my last two trucks were getting close to being out of spec by 50,000 miles I thought I'd do it, and tweak 'em a bit higher for a tad more lift = a smidgen more airflow & power



Vaughn

 

[MCornwell]

Intake . 006Min-. 015Max



Exhaust . 015Min-. 030Max



So your good Vaughn close but not too tight



-Mitch

 

[Prairie Dog]

Soooo Vaughn, what were you doing with the valve cover off?

 

[Vaughn MacKenzie]

Originally posted by Prairie Dog

Soooo Vaughn, what were you doing with the valve cover off?

Thanks MCornwell, I looked all over the 'web and couldn't find those specs



Prarie Dog. . . just BOMBin' it. Come to Rob's this weekend and you'll see

I should have it back on tomorrow. Nothing special, just worked it over a bit and hit it with a can of Krylon



Vaughn