Help, pushrods grew? No rocker valve clearance O-360

[walkman]

Today in an attempt to diagnose some potential morning sickness I started the old rope trick on my O-360-A1F6D.

Got the #4 checked out. Smooth as silk, just perceptible play, valve face looks gorgeous.

However, when I came to reassemble I was unable to get the rocker aligned to get the rocker arm pushed in enough to get the pin through. It was like my push rod grew. Yes, piston is in the right position. Both valves definitely closed. I removed the pushrod tube and fished out the tappet, cleaned, put back in. Same problem.

Any ideas? I'm loath to start the engine with no clearance. Am I being stupid? What is up with my magically growing push rod?

[BobTurner]

It sounds like the tappets/cam followers are full of oil, not collapsed. Try pushing as hard as you can on the pushrods, for several minutes. See if they don't 'shrink'. You must not let up the pressure while you re-install the rocker arm, or the tappets will expand and fill up with oil again.

I didn't think the tappets were removeable, except on the H engine???

[Bubblehead]

Remove the hydraulic lifters, disassemble, clean out the old oil, reassemble and install, then check valve lash. See Lyc overhaul manual and various Lyc letters and documents for more info.

[rocketbob]

I wouldn't take the lifters out, just borrow a valve spring compressor if you can. But if you cant find a valve spring compressor you can take the lifter bodies out with a bent piece of safety wire. To make the lifters leak down before disassembly I always bring a valve open and leave it there for 2-3 mins, then do the same to the other valve. Enough leakdown occurs to get the rockers and pins off easily.

[DanBaier]

... I ... fished out the tappet, cleaned, put back in....

See image from overhaul manual (below). If all you pulled out was a single piece, then it is likely #2 and you didn't get the actual hydraulic lifter plunger assembly (the plunger body and spring).

A couple of things -

When reassembling the pushrod socket (#2), if you put this in backwards you'll have exactly the problem you describe - worth checking out.

When pulling the plunger body and spring - don't drop them and be sure to keep the parts together - don't mix them. (To remove them, use a piece of safety wire with a hook on the end - don't use a magnet.)

To get a good indication of the go/no-go clearance, I'd probably pull the plunger assemblies and clean them up.



Dan

[pat]

I agree with Dan, if you put the socket in backward(easily done) then the pushrod will appear long as you describe.

[walkman]

Or Lifter body. Misspoke. Push rod socket only. Lifter body would not clear the metal cap on the casting where the push rod tube fits. Removed socket, cleaned, and put back in correct orientation.

I did not realize the lifter could re-expand afterwards. Perhaps that is all I am seeing. Engine had not run in weeks, I assumed they would be completely collapsed.

Are pushrods different end to end? Looked identical to me although I'm pretty sure I did retain orientation.

Btw, strong recommend on Valve Wizard from Jolly Time Tools. Much better than traditional valve spring compressor.

[hgerhardt]

The hydraulic lifters need to be bled before you can reassemble the rockers. If you just use the brute force method (rocketbob), the valves might be held off their seats for a while after engine start, with that cylinder misfiring until then.

What happens when the pushrod is removed is, the plunger spring (#3 in Dan's pic) expands the lifter and fills the rest of its travel with oil, making the lifter a now-full-length rigid block.

The proper way to do this is remove the pushrods and shroud tubes, then using a piece of safety wire bent into a small hook, pull out the pushrod sockets and then the hydraulic lifters. Use a toothpick and depress the ball check valve (#10) and simultaneously collapse the spring-loaded plunger on the opposite end. The oil in the lifter will squirt out. Then, reassemble everything. The lifters will refill with oil in a few seconds after engine start.

[speyers]

Originally Posted by walkman

Are pushrods different end to end? Looked identical to me although I'm pretty sure I did retain orientation.

Yes they are identical. They can go either way without hurting anything.

[Walt]

Originally Posted by hgerhardt

The proper way to do this is remove the pushrods and shroud tubes, then using a piece of safety wire bent into a small hook, pull out the pushrod sockets and then the hydraulic lifters. Use a toothpick and depress the ball check valve (#10) and simultaneously collapse the spring-loaded plunger on the opposite end. The oil in the lifter will squirt out. Then, reassemble everything. The lifters will refill with oil in a few seconds after engine start.

I agree with the above procedure, this is way I was taught and has always been the way I've done it.