Clacking sound out of #4 Intake when turning the Engine

[brightcourse]

Reinstalled my engine today, started right up. Then we heard a clang. Upon further investigation, we narrowed it down to the intake on #4. Does anyone have any thoughts on the sound in the video below? We feel the vibration in the pushrod tube and it is very clear that it is where it is coming from. We verified that the pushrod is seated well.

I will note that the valve is moving.

Here is the 6-second video:




Link

[orwell84]

That’s a weird one. I got nuthin’, but someone will know.

[bsairhead]

Valve spring

[Whaanga]

So with a valve spring, might this indicated a stuck valve?
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Late 1973 Bay w/a transplanted 914 Engine

[bsairhead]

[Whaanga]

And here’s the dumb question ….

But is it possible to get the vale freed up from the outside or must the head come off? (And I’m sure the answer is somewhat dependent on the situation/condition of the valve).
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Late 1973 Bay w/a transplanted 914 Engine

[bsairhead]

[Wildthings]

Looks like you have a lot of thread showing on the adjustment screw. How does this compare to the thread on other other screws?

[Wildthings]

You can get oil to the valve stem by just taking a bottle of engine oil and poring it through the valve spring at the retainer end. If that seems to help, then dump a full quart of synthetic oil into a full tank of fuel and let that help lube the valve stem. Premixing the fuel with gasoline will help make it mix instead of just sitting in the bottom of the tank and possibly clogging the outlet.

[Whaanga]

Thank you for the responses.

The real question here is what is the cause of the issue?

If you read through Randy's post, what lead us to this point was a hot running #3 cylinder. We pulled the engine a few weeks ago in an attempt to discover the cause of the hot running #3. We were mostly wanting to see if the new AMC heads on this recently built engine were clogged with cast flashing.

We pulled the engine, removed the push rods/tubes, and the tin underneath the 3/4 side of the heads to get a closer look. Once we took photos of the head, we put everything back together and torqued the valve trains to spec. We checked and adjusted the hydraulic valves.

So today, on startup after the installation, we experienced a smooth running engine (which ran quieter). We let it run a few minutes and then shut it off.
A few minutes later, we were prepping to go on a test drive and started the engine again. This time, it did not start right up, and I was in the back and heard a ticking sound. We quickly abandoned the staring process and soon found the issue as explained above by Randy.

The question I have is, what might have caused this issue? We have to consider the valve adjustment and re-installation of the valve train, but these are things we have experience doing before and we did our due diligence with this work.

We turned the engine many times by hand during the last couple of weeks and found no issues. So again, we are trying to evaluate what might have caused this issue and 'HOPE' we can resolve it.

Jeff
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Late 1973 Bay w/a transplanted 914 Engine

[bsairhead]

A chunk of carbon can cause this.

[timvw7476]

Just pull the pushrod tube, pushrod & check the lifter.
80% chance it came apart. There's a retainer spring that holds the 'guts' together. Either it's let go & made this happen, or a valve seat is popped loose.
Start with the lifter. It may come out in pieces.

[brightcourse]

We pulled the pushrod out on #4 Intake and look what we found...

Suggestions on finding a new pushrod?

[Abscate]

I think you had better fix that stuck valve first.
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.ssS!

[timvw7476]

At least that WAS the proper pushrod for a hydro engine.

[Whaanga]

The valve is not stuck. It moves just fine - I’m pretty sure this was our error with the installation - we didn’t get the rod seated correctly.

To check the health of the lifter and valve, we swapped the rod from #4 exhaust and 1), the noise is. Is gone, and 2), the intake valve moved freely as designed.
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Late 1973 Bay w/a transplanted 914 Engine

[airschooled]

[timvw7476]

Good Catch (on the steel pushrod)
The aluminum body solid lifter units are so thick it's obvious when it's those.
And yeah, bummer. Always 'feel' the ends go in the 'cups'. I unwind my adjusters because I've snagged one or two in the past. And come close to stripping those delicate rocker studs. The tiny ones with 11mm nuts. Treat those gently, you cannot just shove pushrod ends in the cups & torque down, those rockers rae best torqued flush to the surfaces on the heads, all four, before you even think to set lash, solid or hydro. Yes I stripped a nut back in the day. Not my finest hour. : l

[Clatter]

Yep, happens.. BTDT.

I'd be putting your leak-down tester on that hole to be sure the valve didn't kiss a piston and get bent.
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What’s That Noise?!?