So a few moths ago I ran at the track, and after a few runs I started hearing the valves chatter terribly. I had just installed new 1.6 roller rockers. Well fast forward to today, when I finally got a chance to look at it. The rockers are all still tight. When I started it with the rockers off no oil comes out of the pushrods until after a few minutes of warming up, then it just slowly trickles out. I was always told that the oil flew out of the pushrods? Motor is a 350 with vortec heads, hydraulic roller cam.
With the valve covers off you should have a mess on your hands with the motor running. Are all of them doing the same thing or just a few. I see clogged push rods before but they would not pump at all. you say you have 50 to 60 at idle cold.what is it hot?
Hot is 20ish. If I blip the throttle, it sprays oil, but at idle it just kind of trickles. Like I said I had no issues until maybe after 10 p***es, then on the return road I hear clacking. All the pushrods are doing the same thing.
did you check your adjustment again?? The chatter sounds like it is from the push rods hitting the rocker arm. We use to adjust them on the car while they were running and the motor was hot. Back off one rocker at a time. turn down till clatter on that rocker stops then 1/4 turn.
What kind of oil are you running ?,could be broken done and need changing,as said earlier ,you should have a good mess with the valve covers off even at idle.
My GM shop manual for 350 states preload between 1/2 and 3/4 turn. I have seen this setting published in a number of tech articles.......Do a Google search
Not sure about too tight... Snug and then 1/4 turn seems to be not tight enough. I've always done 1/2 turn more. When running, I've even heard of guys turning until clatter stops and THEN going 1/2 turn. Not sure how messy it would be lashing while the engine is running though, sounds messy and a bit strange to me...
When you say in your first post your rockers are still tight, actually, after the lifters set and bleed down, the rocker arms shouldn't be tight. Secondly for the above quote, here is something I found a few weeks ago. My neighbor who is a fairly good mechanic, just changed cam and lifters, SBC, and it just wont run right. Long story short, he explained to me exactly how he set the lash. After some checking, like you he set them for a 1/4 turn after not being able to spin the pushrods any more. I found the plunger in the lifter was being compressed almost .095" at the point of not being able to spin the pushrod. I then backed off all of the rockers and showed him how to set them at the point of NOT being able to move the pushrod up and down, then an additional 1/2 turn. With some ****m ,a scribed line and a simple set of calipers, I was able to show him now we had the reccommended .040-.045 pre-load in the lifter of plunger travel. All 16 valves were now set correctly, and after breaking in the cam, off to the ch***is dyno we went. You could have several other issues at play with your case, but start with the lifter- NO UP AN DOWN then adjust method, as opposed to the No-SPIN method. This is not to start a ruckus, lifters, like most things made in the last decade or so, are not like they were 30-50 years ago. Machining, quality control, etc., etc, explains why my above method is true for the valve pre-load. The springs in the lifter under the plunger do not have the tension of the lifters of years ago as most of us know. BDM.
bulldogmafia is correct don't use the old turn the pushrod method until it stops. But reading your post you say you adjusted the rockers at TDC. The most accurate way is to adjust them by doing one cylinder at a time. Adjust the intake rocker as the exhaust starts to open, and the exhuast when the intake starts to close.
Adjusting Hydraulic Lifters for Proper Preload <?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o> In order to adjust the preload, the lifter must be properly located on the base circle or "Heel" of the lobe. <o></o> At this position the valve is closed and there is no lift taking place. You will need to watch the movement of the valves to determine which lifter is properly positioned for adjusting. <o></o> 1. Remove the valve covers, and pick a cylinder that you are going to set the preload on. <o></o> 2. Hand rotate the engine in its normal direction of rotation and watch the exhaust valve on that particular cylinder. When the exhaust valve begins to open, stop and adjust that cylinder's intake rocker arm. (Why? Because when the exhaust valve is just beginning to open, the intake lifter will be on the base circle of the lobe, the correct position for adjusting the intake.) <o></o> 3. Back off the intake rocker arm adjuster and remove any tension from the pushrod. Wait a minute or two for that hydraulic lifter to return to a neutral position. The spring inside the lifter will move the pushrod seat up against the retaining lock if you give it time to do so. (If you are installing brand new lifters they will be in the neutral position when they come in the box.) <o></o> 4. Now spin the intake pushrod with your fingers while tightening down the rocker arm. When you feel a slight resistance to the turning of the pushrod, you are at "Zero Lash". Turn the adjusting nut down one half to one full turn from that point. Lock the adjuster into position. The intake is now adjusted properly. <o></o> 5. Continue to hand turn the engine, watching that same intake. It will go to full open and then begin to close. When it is almost closed, stop and adjust the exhaust rocker arm on that particular cylinder. (Again, when we see the intake almost closed, we are sure that exhaust lifter is on the base circle of the lobe.) Loosen the exhaust rocker arm and follow the same procedure described before in steps 3 and 4 to adjust this rocker arm. <o></o> 6. Both valves on this cylinder are now adjusted, and you can move on to your next cylinder and follow the same procedure again. <o></o>
Hell, if it's not an oily mess why don't you adjust them running? I concur that they are too loose. you said it does it on the return road? Is it worse at the shutdown?, the start of the return road? If so I bet when the oil pressure comes back down, there isn't enough preload on the lifter. Adjusted too loose, thats probably why they aren't oiling either. Back off the adjusters and they don't oil cause the pushrod has clearance between itself and the lifter cup while running. Just a thought. Start it, with one cover off, Snug em all down just a tad to get rid of excess noise. I'm talking an 1/8 of a turn or so, start by backing one off slowly till it taps. Slowly tighten it till it quits tapping, give it a half a turn, move to the next. If all else fails, look at the lifters or an oil pressure issue. JMO. Lippy
What he said....also....get a old set of valvecovers and cut the top outta them, and do the cutouts in the cover just enough for you to adjust the rockers. After you do the above, start her up....if you hear one clacking, find out which one (or ones) it is, grab your ratchet and just barely snug her down a little more....it should quit. At zero lash, if your preload is 1/4 to 3/4's turn....shoot for 1/2 turn! That way, if you need a little more....you got 1/4 turn more you can go. Also....you might have a lifter leaking down or stopped up. Take the culprit and soak it in some Riselone. And then work the hell outta it on the workbench. Then soak it in some clean oil and reinstall. What ya think Lippy?
i have an old valve cover that i cut the top out of i use it to stop the oil from running down the head onto the exhaust. they also make clips to stop the oil from squirting. brads right while adjusting them while running even at idle its a messy smokey job. you must have an oil restriction .sorry slow typer
Yep, I guess I'm use to wiping oil off the engine anyway. The cut up cover trick is a good one. Clips usually just keep them from getting oil on your new shirt. If your fast you won't make a bad mess. Just don't touch the throttle. LOL. Lippy
When running 1.6 rockers you usually need to open up pushrod slots with a louis tool.And recheck your rocker geometry.
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