Hey, a face to the name! Cool. We don't get that very often around here.
Nice shop/garage/laundramat too by the way.
;D
Not joking, as it's a really nice habitat for your engine!
Now if we can just get it back into a Bronco and driving, all will be right with the world again.
And you're right, that tight one is exactly what you would expect of any valve that is more than just beginning to open against the spring. They'll stay a bit loose in the beginning stages of opening too, but naturally get tighter and tighter (very quickly) as the pressure ramps up.
I figured you'd have more than one at a time that felt at least slightly tight, but that may not be the case for every engine. And it might also be due to any lifters that have drained their oil out.
It did look like some of the other rockers were at least in the initial stage of opening, but not by much.
Be nice if someone else had their engine opened up like that so we could compare movement as it's rotated. Yours seemed more like a low-lift cam than a typical aftermarket upgrade. But looking at the video again it does look like the lift is approaching the typical .500" mark.
Maybe you can verify that?
While it's on the stand you might want to take a cursory measurement (unless you happen have a dial indicator and magnetic base handy?;D) of just how far any given valve opens up. Maybe a small machinist's ruler with very small graduations?
You may not get a perfectly accurate example of course, again since the lifters are likely not all pressurized any longer.
But it would give you an idea of how much each one is opening, and if they are all consistent with one another. Taking measurements of three or four valves should give you an indication.
And as was said, on a non-adjustable valvetrain you just "set it and forget it" usually, but there is also a test for verifying that things are within spec that you do when you are tightening.
I think there are a couple of ways to do it, so maybe someone has a book handy or has committed it to memory. But basically one way is to get a cylinder to TDC on the compression stroke, tighten the nuts until the rockers are at "zero lash" (a bit finicky on that setting and takes a little getting used to for the first-timer. But it's easy once you know how!), then see how much is left to get to the 20lb torque spec.
If I'm not mistaken there is a specification for the number of remaining turns of the nut (like between 1/2 and 1 full turn after zero lash), and also for the distance (measured at the stud threads), or maybe another method as well.
One other thing that's important to valvetrain setup you can check now as well. At least with the one rocker that's not set, get a good look at the tip of the valve stem. Is there a wear pattern visible? If so, where is it?
If it's perfectly centered on the valve tip, then there's a pretty much 99.8% chance that the pushrods are the correct length. Too short or long and the wear pattern moves towards the inner or outer edge, putting sideways pressure on the valve and wearing the guides prematurely.
You're at the point now where you could actually check those. If everything was done right, you don't even need to check as it should fall within spec. But since it was rebuilt and many different things handled, fiddled with, tweaked and potentially machined, it would be a very good idea at this point I think, to verify at least a few of the rockers for that specification.
Again, I don't remember it but maybe some following the thread will. Rustytruck is usually full of all that good Ford technical mumbo jumbo!
Paul
