I have noticeable valve train chatter - not clatter or ticking - on the passenger side when the engine heats up.

About the noise
If you’ve ever listened to a cylinder head (using a wood dowel or stethoscope), that’s the sound - just louder. I can hear it in the cab at idle. It’s not a tick or sharp clatter. Just a smooth recurring flow of rockers and springs - but noticeably louder than drivers side bank.

About the engine
I built the 400 for my 77 F100 about two years back. It was my first time assembling an engine. It’s just a slight upgrade with a Erson cam 214/214) and stock heads. Valve job completed; Top end is all stock except for Erson springs match to the cam. Pushrods are stock. Bought the long block so no prior experience with it.

I’ve already checked the rocker bolt torque. All set at 22 ft-lbs. My initial thoughts are worn rockers that may need replacement.

 

Did you check the lifter preload when you put it together?

You were having oil pressure issues as I recall, that could let the lifters down and cause slack.

 

The oil pressure was definitely a thought. The mechanical gauge has 40 to 70 psi and I still hear the chatter. So I think the oil valve train chatter is incidental to the oil pressure.

As for preload, these are pedestal mount rockers. No preload. So the answer to your question is no. 100% possible I missed the step or put worn parts back into the cylinder heads.

 

Hydraulic lifters always have preload. in your case it's by pushrod length.

 

Could possibly be the push rods are short or a thick head gasket or if someone took too much off the top of the valves dressing the stem, or maybe worn rockers. On this engine, as you say no adjusting, put it together with lifters empty, just lubed and then they grab a bit of oil each time they seat on the cam base, just a little, until they eventually get enough to be full sitting on the base. They get pushed up past the window before oil can escape, and open the valve (unless the lifter bores are so worn they can't fully open the valve because they leak down some). I can hear my engine running, but no loud clicking, etc .... like just mechanical noise. They can over pump if the valves float at high rpms if there is enough travel in the lifter internally, but that's something too that will often as not self correct with time.

I guess you are for sure is no slight exhaust leak that self heals when a manifold gets hot and expands, etc? I mention because my passenger side exhaust manifold to head pipe joint does that, and it's right there at the firewall. Cold weather seems to bring it out until the exhaust build heat. I've wrapped the joint with exhaust putty tape and wire. Once hot, it's quiet.

 

I’m positive it’s top end chatter - not exhaust or lifter. Head gaskets are 0.047” thick. Thoughts on how to diagnose if I pull the valve cover? Pulling each rocker and checking for wear. Measure each pushrod (never performed). I’ve kicked the idea of running it with the valve cover to zero in on the problem rocker(s). Bit I figure that’ll just make a mess.

 

Are you using a stick or hardwood against your ear ... or a real stethoscope held on the valve cover to listen? If you pull the valve cover and run it, yes on a mess, but you'll be able to tell if one is excessively loose. If you pull a valve cover and turn it through two revolutions by hand you get to feel each for excess looseness on closed,

 

I used both a dowel and a stethoscope. I previously pulled the valve cover, checked looseness and also ran multiple rotations with a remote start (coil disconnected). Nothing notable. Checked torque at 22 ft lbs. Next I’m planning to remove the rockers and push rods to further inspect/measure. Other ideas?

 

to check preload you need to put the lifter on the base circle of the cam and check it with a length checker pushrod. it has threads that let you find zero slack then measure it. then add the desired preload to that and get a custom set from Smith Bros or the like. preload is of the upmost importance and it's often overlooked. I'm lucky I live about 30 miles from Smith Bros so I just take my checker to them and say make me a set .

you may find it's okay and this isn't your problem but it should be checked anyway . you don't have to do them all a few will tell you if you need to go farther .

 

I got the micrometer and calculator out along with the passenger bank of rockers and pushrods.



Rod spec is 9.500”. No issues noted. Rod ends also look fine. I also check the fulcrum thickness. All consistent. Rocker wear looks like the example below. All are consistent.

 

When your engine was new those pushrods were what Ford figured would give adequate preload within the manufacturing process of all the parts and the known specs on everything. that doesn't mean much now.

Besides the wear the base circle of the cam can be a little different than your original one, put that together with all the wear, current valve stem height and any machine work and you have no idea what your preload is today. if it's all just rattling around in there that's your problem. it needs checked.

 

I don't know what to say to try now. I'm not familiar with the noise, maybe I missed a video? I hear mine but to me it sounds like mechanical hum of a well oiled sewing machine. I have "A" noise at very low idle, it's steady, like a faint knock, but it's from in the timing cavity and is not like a chain (but I've checked, my T-chain is good), I've determined it is the outer ring on the eccentric that drives the fuel pump as it is bigger than the inner. That .... or it is the fuel pump arm but back up to 800 rpm it's gone.

Back to my thought on your valve train. A hydraulic lifter in these 351M/400 has a floating inner that pushes a push rod, but it gets pushed by trapped oil in the lifter body under it. Every time it goes up / down it passes a window of opportunity to adjust the oil volume against oil pressure once the valve seats (which is when lifter is on the base circle of the cam). It will pump up a little each time only until it has adjusted for any excess room between it and the pushrod linked to the rocker. Once all excess room is full of oil, it won't take in any more as oil is not compressible. During all this, a minute amount of oil goes up through the push rod to oil the surfaces up there at the rocker, but it's limited by hole diameters and time. As long as the lengths are right, there is no preload to adjust as the lifter does it's job, but it needs oil trapped in it.

What can create some noise is lifters that are in bores with too much wear allowing excess oil seepage as the lifter pushes the valve open, which pushes some oil out around the lifter into the valley and then to next time the lifter goes to open the valve, it's got slack that was created the last time it pushed, so in effect the lifter never gets fully pumped up. A lifter needs a good fit in a lifter bore.

I know you said you run 15w40, but I'd try some 20w50 next change. I've run a lot of it in my truck in years past, as well as most of my other vehicles, the Department even supplied 20w50 in those old Plymouths with the 440s, and later 360s and 318s in those baby Plymouths. Main reason I run the 15w40 last few years is I stocked up on the Delo on a commercial customer sale at work at Advance as I used it in my Gold Wing MCs as it was good for the unit transmissions too. When it's gone, I'll go back, use my Kendall GT-1 stock.

 

I think 440 summed up my feeling pretty well. I have no current way of adjusting the rockers absent different rod length. I need to do some reading…

Update: seems like the witness mark approach would be a good start. Base circle for given cylinder. Sharpie on the valve step. Zero lash. Check witness marks after a few rotations.

 

OK, but stock, the lifters will do the adjusting unless something is way off. They should never pump up full travel unless the valves are floated.

​​​​​​​I don't see how one is going to tighten those rocker bolts tight enough to squeeze those rocker pedestals any closer to the head than just torqued gutten-tight as intended.

 

For your purposes now just bring any cylinder to TDC compression stroke , pull a plug to check. if the rockers are loose that's compression, or if the lifters are both down since you have the rockers off.

put the pushrods and rockers back on that cylinder. take the pushrod and spin it, if there's no resistance at all or it feels sloppy your preload is insufficient. it should have minimal resistance. you need to push the plunger in the lifter down slightly that's how it keeps your valve train tight. if it's out of travel it cannot do its job. oil pressure isn't needed because the lifter has a spring to push the plunger up.

To check zero lash you need an adjustable push rod with the correct ball or cup sizes. shorten it up and install it and tighten the rocker down. spinning it with 2 fingers lengthen the push rod until you feel it start to have some resistance. this is zero lash. then you would add the recommended preload to that measurement and that's the pushrod you need. it sounds a lot more complicated than it is.