Actually the air won't close the valve if it is already open. But with the valve closed the air will hold the valve closed. Also with the piston at TDC the valve won't drop into the cylinder. It can only drop to the top of the piston. Also you can tell if you are not on compression stroke if there is pressure pushing down on the valve. Both valves are closed on compression so the rockers are in the up position. Make sure you are on the compression stroke and turn the motor over only by hand. DO NOT USE the STARTER. The battery should have been disconnected when you started taking it apart. Good luck...

 

+1 RedTruck-VA.
TDC is at the top of the compression stroke. Also, the valve will not fall all the way through if the piston is set at TDC or is at the top of any of it's strokes.
It's better that it's on it's own particular TDC as your then guarenteed both valves will be shut.
BTW...what cylider is it that has the damaged spring?
Here's the Hemi firing order with it's appropriate coil pack which is stamped on the intake manifold to the right of the throttle body.

Firing order:
CYLINDER FIRING ORDER (IGNITION COIL NUMBER) 1 8 4 3 6 5 7 2
CORRESPONDING SPARK PLUG NUMBER 6 5 7 2 1 8 4 3

Cylinder #1 is the cylinder closest to you on the drivers side when standing at the front of the truck.

To determine TDC for your damaged cylinder, just turn the engine over by hand and watch the cylinder in the firing order before your damaged cylinder valve and watch it's valves both close shut. That's TDC for that particular cylinder.
The next rotation of your engine, should see your damaged cylinder come up to TDC. You then know 100% for sure, your at TDC for your damaged piston.

In your case, all you want to do is initially get your spring off and check that the valve is OK. Id' suggest that now you know for sure your at TDC on your damaged cylinder and if air is passing, use the rope trick. Just feed the rope into the cylinder as it's coming up to TDC, then slowly hand turn the engine until you feel significant resistance. This is the rope being compressed on the top of the piston/bottom of the head.
Then, put a zip tie at the very top of the valve stem when you've got the spring off. That will make sure the valve won't drop into the cylinder. That worry is now removed for you.
Remove the rope, by turning the engine by hand in the reverse direction and slowly pull the rope out. Just turn the engine over a bit, just eough to remove the rope. Pull the rope out and inspect it very closley, making sure none is left behind.
Turn the motor slowly over by hand past TDC, so there is enough room in the cylinder for the valve to move from fully closed to fully open.
With this distance set, gently rotate the valve in your fingers, all the while letting the valve slowly slide down to it's fully open postiton. If you can't feel any binding and the valve slides relatively easily up and down it's guide, your valve is OK and not bent. Make sure that at the closed position, the valve is fully shut. That's the acid test and you must be 100% sure of that fact. If any significant sticking of the valve is felt and you have to push the valve to get it to move, it's bent and you will have to pull the head.
If all's good, re-establish TDC on that piston and install your new spring.
When re-assembled, rotate the whole engine over slowly with a breaker bar and watch/listen to your valve train paying partivcular attention to the new spring. Make sure that it's moving the same as the rest of the other valves with no strange noises etc.
If everything looks OK, button her up and fire her up.
Then you can do your yee haa dance and take great delight, in solving a very nasty problem.
Sorry If I've walked you through this a bit slowly. Please don't take offense.....I don't know your level of experience, that's all.
The best of luck on this and get her done.
Al.

 

Yep, take your time and follow Al's steps and all will go well. Good luck.

 

Glad to see you are making progress with this.

 

Al,
Awesome explanation of the process and best of luck to the op on his repairs.

 

Why thank you sir.

I think that when the OP gets right in there, things will become a lot clearer.
I hope we can help the guy, as I think we've all been in situations where we are really really worried and need to get things done correctly, but cheaply.
Good luck to the OP and post up if you need any futher help mate.
Al.

 

Al, thank you so much. That's basically what I need, to have my hand held thru this task. My level of experience is none when it comes to this. Only that I helped a dear friend on a cam/spring/push rod/timing gear swap on my LS1...many years ago and basically I was just a hand there when needed, so I don't recall much of it...and the exact process of the why's...do's and don'ts were not explained to me.

So, with you and everyone else walking me thru this slowly is the best help I could ask for anywhere. I'm on pins and needles, couldn't get to sleep til about 330am this morning. I'm self employed, my wife was laid off back in December and I've got to get this truck back on the road by this weekend and as fast and as cheaply as possible. So, yes, I am very strict in making sure I get it done correctly and praying that my valve is ok.

I am headed out, to get this done. I will post up the results. Also, wait til you guys see what I made a spanner wrench out of to get the fan clutch nut off. Cost me probably 30 cents and took less than 2 minutes to break that nut free. Yes, took pic's of it and will post up.

You all have a blessed day and I look forward to posting positive results later this afternoon.

PS It's the #5 cylinder top spring which is the intake.

 

So, you want to be watching the valves on #6 cylinder, as they open and close when you slowly turn the engine over. When both valves are closed and the piston is at TDC (use the wire coat hanger ethod to find that out) the next cylinder to reach TDC will be your damaged one. Turn the engine over slowly and watch cylinder #5 valves both shut. That's TDC right there.
It's unusual that it's your intake spring goosed, as previously mentioned it's usually the exhaust valve springs that go.
I hope you have some good luck this afternoon bud. Will be thinking of you and post up if you need further help OK.
Al.

 

DF memebers...isnt there someone near by who can lend a hand if needed?

 

just read through this thread. VERY informative. looking forward to hearing how today went...