Need a 351 valve adjusting procedure

[Dbarnes72]

I've read several (sometime conflicting) posts on hydraulic lifter valve adjusting procedures. Can somebody post up an easy to follow procedure?
Engine is an '84 351 non-roller. It's a fresh rebuild (from somebody else). Starts/runs but it has an upper engine noise that is present at all engine speeds and changes with speed change. It's like an amplified sewing machine. I pulled the distributor and checked gear condition. All good. Listened with a mechanics stethoscope and it's not isolated to any single cylinder area. My thought was to make sure the lifter/rockers were at the correct tightness and go from there. I pulled one valve cover off last night and didn't run it but it looks like oil is well distributed.

 

[Viperwolf1]

You can just torque them down to 20 ft-lbs. If you still get noise there may be a problem with pushrod length or damage somewhere.

 

[Hazegray]

Double check your valve covers to ensure the rockers are not hitting them, especially the oil "baffel" in the oil fill plug.

 

[half cab]

Make sure no manifold /header leak? Just a thought.

 

[DirtDonk]

Is it a Ford EFI setup, or carbureted?
If EFI, some injectors can make a heck of a clattering that sounds just like lifters.

Paul

 

[metal1]

Installed a rebuilt engine that had lots of upper valve train noise ended up the rebuilder had re used worn out rockers and trunions ,I haven't seen that builder in yrs

 

[DJs74]

Do you know what camshaft / lifter combination you have? Brand, P/N, etc. Adjustable or non-adjustable? There is a difference depending on what style you have. If non-adjustable type, they are torqued to a specific spec and that's it as Viperwolf stated. If by chance someone has converted the valve train to adjustable style, it is more involved but not complicated. The reason I ask about the brand is because a few years a go, I installed a hydraulic Comp Cam XE (extreme energy) series camshaft with converted to adjustable rockers and had a lot of lifter noise, they actually sounded like solid lifters. I called Comp and they claimed that the lobe design of this particular series had an aggressive ramp profile which made them noisy by design. I never had any problems, had great performance results but just noisy valve train. I had a few other people tell me later they experienced the same thing with this camshaft.


DJs74

 

[tirewater]

Heh, a long shot, but thought I'd mention.

I left my AIR holes on the cylinder heads unplugged when I first started my engine after rebuilding. You could hear each valve snip shut...quite a racket.

Not sure if your heads would have those holes (in the back for the newer engines).

 

[Dbarnes72]

You can just torque them down to 20 ft-lbs. If you still get noise there may be a problem with pushrod length or damage somewhere.

So, Viperwolf, are you saying they can be torqued to 20 ft pounds in whatever position they are in or do I have to get the intake and exhaust valves in a specific position (e.g. full open)?

Unfortunately, all of the suggestions above don't apply to this one. Good lifter clearance, etc. I'm not ruling out exhaust leak but it's running open headers and it just sounds too uniform for that.

 

[Viperwolf1]

So, Viperwolf, are you saying they can be torqued to 20 ft pounds in whatever position they are in or do I have to get the intake and exhaust valves in a specific position (e.g. full open)?

Unfortunately, all of the suggestions above don't apply to this one. Good lifter clearance, etc. I'm not ruling out exhaust leak but it's running open headers and it just sounds too uniform for that.

You don't need to get anything in a specific position, just torque them down. Not enough spring pressure to make any difference.

 

[Oatmeal]

You can just torque them down to 20 ft-lbs. If you still get noise there may be a problem with pushrod length or damage somewhere.

X2
They're non adjustable
I converted my heads to screw in adjustable studs and (rail) rockers because I didn't like the press in studs.......heard of them pulling out on higher mileage heads and higher than stock spring pressures.
Could be the studs are not seated all the way or they're starting to pull out
Just a thought.
Hans

 

[blubuckaroo]

I've seen a few Ford engines where the owner thought the valves were adjustable, and tried to make a running rocker adjustment. That would work, but the rocker nuts aren't the "deformed" locking type, and would keep backing off.

 

[Dbarnes72]

I torqued to 20 ft. lbs. as suggested with no change. I recorded the running noise yesterday. It's pretty clear on my iPhone but the desktop computer tone control kind of masks the rattling. I'm sure there is an exhaust leak and probably vacuum leak as well but the "rattling" is the valve clatter that follows revving the engine. It's present all of the time but more pronounced as the engine idles down after revving.

https://youtu.be/PJcld568tYw

 

[Rox Crusher]

If you re-torqued them and the noise still seems excessive.......

Can you move or rotate any of the pushrods by hand ?

If so, they are too loose.

 

[Timmy390]

Stock 351W's do not have adjustable valve trains. I know the manuals refer to "valve adjustment procedure" but it does not apply to a stock engine. Not sure why it's in the manuals as it confuses people all the time.

More about your setup please

How many miles on the engine? Stock engine? Fresh rebuild? When did this start? How many miles? Both sides making the nose? What oil are you running?

The issue could be cam lobe wear, lifter wear, bad lifters, wrong push rods, bent push rods, worn out rockers and trunions etc.

Do this.....remove the valve covers and see if you can freely spin the push rods and if the rockers can be moved around. See if the push rods can be moved up and down. If so that's the source of the noise (slack in the geometry). Then start checking parts looking for wear.

Tim

 

[DirtDonk]

Do the check they mention, but don't put too much stock in being able to rotate the pushrods in their sockets. Even on a perfectly adjusted and functioning setup, you can almost always spin a pushrod in it's fixture. They're so precisely fitted that they rotate easily. Even in some cases, almost with the valve fully open.

If the valve is closed and you can rotate then, it might not mean anything by itself. But very easy rotation along with ease of moving it up and down would be indicative of looseness.

With pressed-in studs, it's very easy for them to start pulling out on an old head and you'd never get them adjusted properly.
There are probably shims for rockers who's studs are too tall, or for whatever other reason they are not to spec. Never had to use them, but I bet their is something like that.

Regardless of the torque applied, there is also a specification for just how many turns from zero lash or something like that. Best to read the book unless someone here can quote the procedure for checking.

Paul