To add to Ron's post.
Number one piston will also be at top dread centre with the woodruff key slots aligned like Ron said (they're facing vertically to each other)
Number one being the front left piston when facing the front of the engine.

 

Thanks. That's close to how it looks going from memory but I'll check closer and check the chain stretch like Haynes suggests as it does seem a bit sloppy. I haven't had much time to look at it recently but I did find something I can't explain.

I was careful to keep all the rockers and rods in proper orders and organized so I know the #1 rockers and rods are in their original locations. However when I put the leak down tester on #1 and have torqued the rockers at TDC there is no position where either one or both (?!) valve ports seem to leak pretty badly. If I loosen the rockers slightly there seems to behave as one would expect (leak down is <5%). In the past I've had rocker arm gap adjustments, but this engine doesn't seem to have that but the rockers seem too tight on the valves (I've only looked at cylinder #1 very closely like this). Again there's really no crankshaft rotational setting with the rockers on #1 torqued down where the valves won't leak. However easing the bolt out (at TDC) so they aren't depressed will seal up the cylinder tightly and rotating it behaves like you would expect on the cycles.

Are there specifications somewhere that I could use to check to see what might be out of tolerance or what might be causing this? I'm not sure where to look to figure out why this is happening. I was thinking a bent cam shaft, but I'm not sure it's possible for all the cylinders have this same problem. The rods all look good and if the rockers were worn you'd think I'd have gaps and not this case where the valves are depressed slightly.

 

Something is very wrong if #1 valves open when tighten down with CAM mark at 6:00<<<<<this set #1 TDC not the Crank, although the crank mark should be at 12:00 at this time

Hydraulic lifters should be compressed a bit but you should be able to spin push rods with fingers

Did you change lifters or push rods?

 

No I didn't change the lifters, rockers or rods. Good to know at TDC the rods should be able to spin a little. There doesn't seem to be a rotation where the valves aren't slightly open but I'll look closer at the TDC. I remember the exhaust seemed closed but the intake was slightly depressed. It's kind of hard to do with only two hands because the cylinder doesn't want to stay at TDC with the leak down tester air pumping in.

 

Timing chain slop will not cause zero compression, nor will badly worn rings.
When my Dad was young he drove around this 53 Ford that was so worn out on the rings, it would not start very well.
He lived at the top of this big hill where he would roll it down the hill to get enough compression in the engine to get it running.

I still think your lifters are the problem, it sounds like they're all varnished up, full of milky oil and stuck.

The lifters on these trucks are very close tolerance (as with most vehicles).
My truck was a city truck, lots of short runs and the engine was badly varnished up, including the lifters (some ticking)
I couldn't get the lifters apart with out heating them up with an oxy acetylene torch.

I don't really have an explanation as to why the engine ran for that short period of time and now it won't, assuming it is the lifters, why would they work and not now ?
Maybe there was just enough heat in the engine to effect them and stick them in place.

It's the only thing left that could cause zero compression.

 

I don't know why it ran fine and sounded really good which inspired me to start this adventure rather than sell it for parts.

The lifters seem to move pretty freely and don't appear varnished. I've ruled out the cylinders, rings, head gaskets and the valves themselves because the leak down results are really good as long as the rockers are not torqued down and opening the valves. I also injected higher pressure directly from my compressor and the cylinders were all tight under that condition too.

I'll research the rockers, rods and lifters and see if I can find some tolerances to check.

 

Are we talking about the same thing ?
I'm referring to the internal workings of the lifters them selves, not the lifters moving with in the block itself.

 

Any idea how much material this machinist removed to make the heads flat/true ?

I'm thinking valve stem length might be to much.

Might be possible to correct with a thicker head gasket, if that's the problem.

 

It appears that it might have been a non-trivial amount. Perhaps they were warped. They were very busy and the guy who did the job wasn't there when I picked it up. Since I've done this before for other engines at this shop and never even remotely had a problem I was feeling overconfident and didn't really worry about it.

I think the tolerance stackup to the top of the rockers might be related to the problem. Can the rockers be shimmed? Is that something that is done?

Any idea where I might be able to find some reference of the lifter to rocker travel heights? I'm not sure what to call it or where to start.

Maybe a kit like this for $15: https://www.summitracing.com/parts/fms-m-6529-b302

 

Michael (Supercab) has given me a plausible explanation.
If even 5 or 10 though was taken off the head, that would move the hydraulic workings of the lifters into a different position.
The different position of the plunger inside the lifter moved into an area where there was varnish build up and now they are stuck internally.
The varnish build up was made even worse from all the milky oil.
This would cause a " no close" on the valves, or at least on the intake or the exhaust, enough to cause "zero" compression.

Eric, if you have to shim the rockers, then that should not be necessary, proper working lifters take up any discrepancies in valve wear and or how much material was taken off the head.

The only exception to this is when Ford started using soft valve seats where they were literally hammered into the head, the lifters could take up the space created by the faulty valve seats.

I can't be actually 100% sure this is what is going on, but I'm betting a new set of lifters would solve the problem.

When installing new lifters, after installation, remove all the plugs and turn the engine over by hand at least 2 full revolutions.
After that disconnect the ignition and use the starter to fill the new lifters with oil; about 15 to 30 seconds of cranking, or until you see oil coming up the push rods and onto the rock arms.

On this engine you can also remove the cam shaft sensor and use a drill, an extension and a small socket to turn the oil pump over to do the same thing, but of course you would have to note the position of the sensor.
It's also advisable to use some masking tape to hold the socket on the extension so it doesn't accidentally fall into the oil pan.

 

Thanks. I'll look into getting a new set of lifters and give it a try. And since I have the plugs out now, I can pretty easily spin the engine to move the oil around.

Edit: Do you think it's viable to remove and clean the lifters or do they need to be replaced? Many people on the web recommend just lifting them out with a magnet, But there seems to be something retaining them when I lift them up. There appears to be a metal retaining piece that covers a set of forked bars that sit around the lifters. Does this need to be removed to extract the lifter?

 

You may try, but if they are stuck in place like I think, getting them apart will not be practical, no amount if soaking in anything will dissolve the varnish build up.
Plus it's a very tedious job, it would take you a weekend to do so _ very fiddley.
Mine were bad and it took the heat if an acetylene tourch to expand the outside enough to get the piston out, but of course that sort of heat destroys the return spring on the inside, so that doesn't really work either.

The thing that retains them is called a spider, it keeps them from rotating in place because they are roller rockers, so that needs to come out first and after that they should just lift out, but they can get stuck if the bottom half has varnish build up on it, so be prepared for that.
After the spider comes out, note the orientation of the bar on each set of lifters, that has to be put in correctly so the tangs of the spider keep the bars in place properly.
You'll see once you get in there.

 

Here's a video, but the guy totally forgot about the check valve to take it apart and clean that.
It involves a very fine spring and a steel ball bearing.

 

This is all I could find, it's a terrible video because it's so dark, you can't see anything. (it's a 302, but it's exactly the same plus two more cylinders)
Also the guy is soaking the lifters in oil _ that does not do any good, they have to be in the engine and pumped up with the action of the cam to fill with oil.

 

Thanks Jeff, SuperCab, and Ron. I understand a lot better what I'm looking at now. I think I'm probably going to be better off buying a set because I see now how badly worn they probably are inside. I'll take one apart just to see what's going on inside and if they are likely a problem but it makes a lot of sense that they could be causing problems with the rockers opening the valves. I suppose there still could be an issue with the material being removed but I'll try the lifters first and see how that goes. If I'm lucky I'll find something locally that's not too expensive.

 

I have these in mine and it's been a couple of years now.

https://www.rockauto.com/en/moreinfo...38302&jsn=1014

 

I know it's been a looong time, but I finally got the lifters and push rods. The old lifters were shot. Once installed the rockers were right and the leak detector looked good at TDC. I borrowed a compression gauge from the auto store but it would never register compression and wasn't reading right using my air compressor. Unfortunately I was not able to get PSI numbers for the cylinders.

Long story short, I got it to fire up and run. It's a little rough for some reason, but I haven't been able to run it much because I need to test the coolant system (hole in timing cover, new pump, etc.) then commission the transmission (rebuild).

Thanks for all the help on this one. I have a lot better understanding of how these engines work now, that's for sure.