Valve Adj.

[Walker]

Just finished looking at the Cummins web site, and saw they recommend the first valve adj. at 24,000 miles, and every 48,000 after that, for the B series motors.



Anybody doing this? (don't hear much about it)



How do you tell when you do need one for sure? (I wouldn't think you'd hear the clatter like on a gasser)

 

[Archive]

Walker... I see you are showing a 2001 24valve in your signature... I believe they don't suggest a valve adjustment til ya are over 100,000 miles. I'll have to look when I get home.

 

[Mopar-muscle]

i think 150k is the number on a 24valve , just for kicks we checked 2 a couple weekends ago , mine and massdiesel , he has around 40k on a '99 and i have over 50k on my '00 , both were well within spec .

 

[Archive]

Just looked it up...



Schedule A... 150,000 miles.

Schedule B... 135,000 miles.



Good call, Mopar Muscle!

 

[Chad Sheets]

If you are going with stock, thats good, if you are pushing alot of power (400+HP to the ground) you might give them a check every 50,000 miles or so. Things wear and carbon up much faster with extra fuel. I checked mine last Christmas time and all was well.



If you do decide to adjust them here is how to do it THE RIGHT WAY to do it.



Back all the adjustment nuts off on all rockers, then run them down with

your fingers until they touch (you will only be able to run down the rockers

with no tension on them... the ones with tension will have to wait their turn

on the next round when you rotate the engine 360 degrees. Zero the gage out

and adjust for ever how many mm or whatever measurement you want to use.



1. Put cyl #1 on TDC by using the TDC mark behind the crank case breather

on the front of the engine. You will have to remove the breather... I

believe it unscrews. You will see "TDC" stamped at 12 o'clock inside the

case and a mark on the fuel pump timing gear. Put that mark on the 12

o'clock TDC position.



2. Remove the valve cover, and mark the following INTAKE valves with a

paint marker, 1,2,4.



3. Now mark EXHAUST valves 1,3,5. with the paint marker. You should have 6

rockers marked now.



4. Adjust the INTAKE valves somewhere between . 15mm and . 38mm. , I shoot for

the middle of the road . 25mm.



5. Adjust the EXHAUST valves now between . 38mm and . 76mm. , again I shoot

for middle of the road about . 57mm.



6. Give all the rockers a good wiggle before removing the gage to make sure

all the play is out of them.



NOW ROLL THE ENGINE OVER 360 DEGREES AND ADJUST THE 6 ROCKERS NOT PAINTED

WITH A DOT.

 

[Chad Sheets]

I forgot the most important thing... rotate the engine in the direction it turns only. If you miss your timing mark by going past it, dont turn the engine backwards! Go another 360 deg around until it comes up.



There is play/lash in everything on that engine. Rotating the engine backwards changes the valvetrane geometry and all your adjustments will read differently once the engine turns back the way it normaly rotates. You wouldnt think it would matter, but it does. Valve timing is critical for a diesel. Depending on the severity of the lash on a "backwards" adjustment, you can see EGT's rise real fast because the engine will run hotter with the valves out of whack.

 

[Walker]

Thanks

Thanks for the help boys. Then all is well here for now, good to know.

 

[Vaughn MacKenzie]

Also spinning your engine backwards makes the oil pump go backwards, and it can lose its prime. When you restart your engine may be spending precious seconds running without oil pressure!



Vaughn