Just got my new motor back together and in my car.  Adjusted the valves and now for some reason they are coming lose.  Here is a little bit of info.  I have a lunanti cam, 1.6 full roller rockers and screw in studs.  

Over the weekend, I adjusted the valves with the car running, went a 1/4 turn and locked the rockers.  Drove it around and it was fine.  The car was running for over an hour at idle for the most part.  Now I took the car out yesterday for a drive and was about 4 or 5 miles from home the car started to run like it was missing.  The lifters started to make noise.  I turned around to head home and I started to smoke out of my tail pipes (white smoke)  Can lose rockers allow oil to get into the cambers and smoke like that?  I pulled over and tighted the rockers up a little bit.  I was able to limp home but I was still smoke and the lifter were still making noise.  It is a brand new camshaft and lift set.  I am going to check the studs to see if they came lose (they are the screw ins).  Can the lifters be bad?  Can the cam be bad?  I did break the cam in too for about 15 mins at around 1500-2000 rpms.  Any advice would be great.  

thanks  

Check the dipstick,look for white or watter droplets in it.You may have coolent getting in the oil somewhere and this dilluted the oil.By thinning the oil out your preasure may have dropped enough so the lifters are not pumping up.Did you have the heads off? Let me know what you find.The whole reason you wanted screw in studs is so push in ones tend to pull out under high lift or more spring preasure.You may have adjuster nuts that are shot.They are a locking style nut but after beeing turned quite a few times the locking part is worn out.If there is any doubt change oil and filter.You did do this before you started it right?  

yeah it was a fresh motor.  The rocker arms were only used for about 5000 miles before I had to take it apart and rebuild it.  I got new heads a while back that is why the screw in studs are there.  When I get a chance I am going to tackle this again and see what I come up with.

I checked the oil too, and it was fine, no water or gas in it.  It is very very weird.  Thanks for the help.  I will let you know

Something else to look at... if you're using poly-locks, the end of the stud should be machined flat.  Not all screw in studs (purchased off the shelf) are machined flat, and need to be ground flat prior to installation. 

If they're not flat, it's then possible that the poly-lock is not properly secured to the stud and therefore it's working loose. 

Here is the thing...I had these rockers on the motor before I took it apart and all was fine and dandy!  Now all of the sudden, they seem like they are not locking...can the locks go bad?  

Also when I first adjusted the valves, the lifters were still making noise...

thanks for all the help!!!!

 

Also when I first adjusted the valves, the lifters were still making noise...

Take the manifold off and check the lifters, it sounds like you lost the cam. All this costs is a gasket set, if you keep running it it will cost you the crank due to metal debre from the eatin up cam.

Are you getting oil through the pushnd? Anyway I think you shold set them with the engine off the way the book says.Something like 1/2 torn after you cant turn the pushrod with your finger.I think some are too lse and some are too tight.  

P.S the reason I was getting into the oil question was you said white smoke out the tail pipe.I dont remeber the specs of your cam .But I just thought about this.Are you running long slot rocker arms?Do you need to with your lift? If so you may have a binding action gooing on .Also check the pushrods for weas.Or even bending if they are not strong enought.If you are useing guide plates you need hardened pushrods or the rods will wear right through.And as I mentioned before are you getting enough oil to the rocker arms.Eun another compression test sometime to make sure you dont have the valves stuck in the guides or something.Just make sure all cylinders are pretty even  

Thanks guys for the help.  i re did the valve timing over the weekend.  I took the locks off and rockers and cleaned them so there was no oil on them (A fresh start)Did the valves and all seems to be ok now, until there was air in my water system.  Will have to take care of that another day.  But it seems that there might have been oil on the rocker stud and on the locks and I just could not make them tight enough.  Who knows.  It seems to be holding up for now.   I have to get the air out of the system and drive it some more to see if they make any more noise.  But thanks all for the help, it was all very very usefull!!!!!!!!!!

Glad to hear about your sucess.I dont have any of my own projects gooing on so I live through you guys  

thanks for the help...

here is another funny  thing that is going on.  After the motor is warm, I get a very soft noise...sound like the lift is taping.  But only when the engine is warm.  It goes away if I give it a little gas....very strange.  Can it be lose.  I did that valve like 4 time to make sure it was good.  Can it just be that I need to change the oil since the motor is being broken in.

thanks again

Bryan

 

Well Iwould change the oil anf filter.This stuff is cheap.Some of the assembly lube can plug things and on a fresh engine you have a lot of metal in the oil from the break in.Sometimes you may hear noise from the distrubitor.Last week I used a mechanics stephescope to isolate a noise on a forklift engine.It has been years since I used one.Theese things are great.If you cant find one at a decent price try harbor frieght this place is awsome and there are only a few manufactors stuff they sell that is cheap .My boss spends around 1500 dollars a year there .So I know what they have.If I never saw their products I would of assumed it was all junk.  

that is what I was thinking...an oil change might help.  i will do that when I get a chance.  Have to drive the car now, my Daily driver will not start now...ugh!!!  

WEll I changed the oil in the motor and still the samething.  When the car is cold it does not make the noise.  But once it warms up it only does it at idle.  I swear it sounds like a lifter....When you give it some gas and bring up the RPMS the noise goes away.  Can there still be dirt in the motor?  Fuel pump rod?  Wish we could just stick a camera in there to see what is going on.

This sounds like a problem related to a loss of oil viscosity as the engine warms. This is natural for oil (especially mineral types) the stuff simply becomes thinner as it heats up.

One of the first things I'd check for is hydraulic lifters that can't hold stiffness as the oil warms and thins. They leak internally past their valving and the forces of spring pressure and cam motion cause them to leak down a small amount. This opens up what is essentially a lash setting and the lifter, pushrod, rocker and valve stem no longer are in contact at all time. The first result is a noticable ticking sound as the "lash" is taken out as the rising lobe forces everything back into contact with each other.

There's a couple ways to check this out. The cleanest is to take a piece of dowell, or screw driver, or a mechanics stethoscope; then go over the rocker cover moving one cylinder location at a time and try to identify the area where the sounds are the loudest, which should indicate the most likely source of the ticking. The dirty way of doing this is to remove the rocker cover and with the engine running hot and ticking place your thumb on the pushrod side of the rocker and push as hard as you can downward toward the cam. This should stop the ticking of any lifter to rocker combination that is doing so.

Actually once you identify an area where the ticking is coming from with the "stethoscope" method, the later dirty method will be necessary to identify the specific source.

Once identified the lifter(s) needs to be replaced, tightning beyond spec does not solve the problem and encourages the lifter to keep the valve off the seat when the engine is cold and the lifter is fully pumped up. Do this enough and the valve will burn. 

Bogie