wadecool

I adjusted my valves yesterday & I think I adjusted too tight. I tried to get 0.10 at intake, 0.20 at exhaust but it sounds like its tight. Can you tell me the proper way to use feeler gauges? What would my motor sound like if valves were tight? Will it hurt the motor if they're tight?

pind

If you could pull the feeler gauges out from between the crossheads and the rocker arm pad, without any great deal of sweating/swearing/strain, then you are not too tight.

The method I use, is a 6 in/lb torque wrench, put the feeler gauge in place, run the adjuster down to 0 + 6 in/lbs, then tighten the jam nut while hold the adjuster screw in place. This gives you an as close to perfect set, as you will ever achieve. This is also the method used on larger engines.

I used to use the "drag" method, but I always found that everyone's feel for that is different. Besides, wearing my sunday dress while setting valves, just made the laundry folks mad.

Have a good one.

Tocapet

Another method is the Go/Nogo method. a 0.10 goes, but an 0.11 doesn't. There are some feeler guages that have a
"step" on the guage blades so you don't have to be swapping blades to check.

wadecool

How much drag should there be when pulling the gauge out? Do I have to torque the adjusting nut/locknut? What effect will tight valves have, can it break something?

wadecool

I forgot to ask, how long do I need to let the engine cool down before I can adjust the valves? I want to readjust them when I get home today.

Tocapet

You need to adjust them when the engine is completely cold. Best to do it first thing in the morning after it has sit all night. Look for the FAQ on here and you'll find instructions with pictures and all.

pind

Cold is considered to be anything under approximately 140 degrees. although, I would tend to go with less than 100 for sure. Normally I will do them truly cold, as has been suggested, in the morning after an overnight cooling off period.

The adjusting nuts should be torqued, I believe the spec to be around 18 ft/lbs per cummins service manual. As well, the 140 degree mark, listed above is also in the service manual.

As far as how much drag, get this "NOTE: Clearance is correct when some resistance is "felt" when the feeler gauge is slipped between the valve stem and rocker lever" That is verbatim from the B series service manual, courtesy of Cummins. Now do you see why I use the 0 + 6in/lb method?

Anyway, if the valves are too tight, there is a chance of a valve staying slightly open, and burning, or, in extreme cases, you could smack a valve with the piston. That being said, you have to be a fair distance out of adjustment for these things to happen.

Just go with the 10 and 20 set, and leave it at that, you should be fine.

fschiola

Although the advice for setting the valve lash at 0.010" for Intake and 0.020" for exhaust is sound, Cummins specs are 0.006" to 0.015" intake and 0.015" to 0.030" exhaust. Keep in mind that changing the settings one way or the other can in effect change your timing. Also when using the "go, no go" method you could try using a 0.009" to "go" and a 0.011" to "no go" giving you 0.010" in the end.

Tate

This is the way I did them. I'm not too concerned about the drag when pulling them out (although its a good indication if you're out). I set them, and then get the .010" feeler in. Good. If I can get the .011" in, then I readjust them. If I can't get the .011" in, but can still get the .010" in, then I leave and go on to the next one.

NoSeeUm

From the old school, (my Dad's method) "If you can lay your hand on the engine comfortably you can adjust valves"

I use the guess method. I back off the set nut a 1/4 turn or so. Then I adjust the tappet stud a bit loose on the feeler. Then tighten the set nut letting the adjustment tighten with it. Now I recheck with the feeler. If it is good it is good, if not then do it again. It only takes a couple tries to get the feel for it and I find it much faster and easier to do that way.

Jim

wadecool

I tried the go/no go method. What I did was if the 0.11 wouldn't fit, the 0.10 would be fairly tight. It seemed like there was a lot of drag. Does that sound right? My motor has a pretty low sound, & the exhaust sounds like it has glasspacks.

jrs_dodge_diesel

I was taught the over/under technique. I would use the .010 for the initial setting, and then check with both the .011 and the .009. When I would check, if the .009 fit easily, and the .011 didn't fit at all, then I knew it was set good on .010.

wadecool

Thank you guys for sharing your knowledge! I finally got my valves set right, and even with 240,000 it still sounds great. With all the great advice on this site, I think I can get a million miles out of the old girl.