Collapsed Lifter?

[Freakin A Scrib]

This might be dumb, but I hate doing the same thing twice and wasting money... I assembled my stroker with roller rockers and wanted to figure out push rod length to get the appropriate path across the valve tip. In that process, I turned over the engine with the valve train assembled. The hydraulic lifters had never received oil. When the process was done, I realized a couple of the lifters had lost their springiness (collapsed). I then primed the oil system hoping it would bring them back, but it didn't.

The question: Do I need to take the head off and replace the lifters? This would waste the head gasket and the head bolts, wouldn't it?

[SilverXJ]

Yes, you need to pull the head to replace the lifters.

However, don't fret yet.

Bring the cylinder up to TDC. Remove rockers and pushrods and wait 5-10 minutes. See if the lifters returned to top... usually you can look down the bore and see them. Or just remove all the lifters and pushrods and wait them look at them.

Also, just because they aren't springy doesn't mean they have a problem. They may just be filled with oil.

[IH 392]

I'd fire it up and see if they were bad before I tore it back down!
I built a Chrysler 225 once that had the late hydraulic valve train, they oil bass akwards! the oil goes from the rockers to the push rods then to the lifters!, I pumped them up by hand during assembly and it sounded good when I fired it off, but shortly after and within about 5 minutes all twelve lifters were ticking!, after about twenty minutes of chin scratching and three of us ready to tear back into it all of a sudden they all quieted down and it sounded like a sewing machine!, we sent it out and never saw it again.

[6TIME]

You should at least try firing it before doing anything. The lifters work like a check valve as they move up and down with proper oil pressure, which pumps them up. I've never seen one pump up with just priming the system.. They need to be in motion. Sometimes it takes a few minutes of running for them to take up slop and adjust to the valvetrain. Especially, if it's a new set of lifters and they have air in them...

[SilverXJ]

x3, I'd go ahead and run it first. I bet its fine as long as preload is in spec

[Retlaw01XJ]

Check lifter preload first, then fire it up.
Your not likely to damage a lifter by bottoming out the plunger, that happens in normal use. Unless something is so out of spec that you run out of clearance, such as too much lift for a spring and it 'coil binds' (becomes solid). That usually results in a bent pushrod or broken rocker.