z0sicktanner

I did this video today. It shows different valves and how they wear. These are SS Valves and what they look like when they have miles on them.


These are all the other videos I have posted over the past year or so. Please take no offense if I sound mad in some of these videos. At the time I was.
















Look at these videos and make up you mind. I take this very seriously.

jedblanks

I would like to see a picture comparison of an ls7 stainless one pc valve out of bronze guide with 10k street miles vs the stock ls7 valve at 10k

But I think the comparison in the video to the mustang valve yields the same result.

People around here say the valve stems do t wear, but mine were. Half the clearance was guide wear, the other half was stem wear.

z0sicktanner

I dont have any ls7 valves I have cut them up to check wall thickness I will have another set soon with valves but not with bronze guides. when I get them I will post up

LT5 John

Thanks for taking the time to post up the videos...Big help to those of us that are concerned...

JwT

Rock36

I love watching these videos, they really help with putting it all together.

Do you ever get LS6 heads in? One of the more common arguments is that since LS6s had sodium-filled exhaust valves that worked then that means the LS7 sodium-filled exhaust valves must work too.

66L72

I have a set of valves and guides from my recent rebuild.
Trouble is they are not matched,just mixed up in a box. 16 guides and 8 valves.

'06 Quicksilver Z06

Very informative videos Chad.

Thanks for posting all of them up in one thread.

ByByBMW

z0sicktanner

Thank you Sir It is clear what is causing this Heat and valves that can't be quality controled. this is why some guides wear more than others this is also why some cars make it 170k. please guys listen to me gm is covering their *** on this issue. yes I do ls6 243 casting heads alot I've done a few hundred sets. I have not seen burnt marks on the valves. the ls6 heads used diff valve angles 15'vs ls7 12' but a diff company made these valves and they got them right. this was the main reason why I thought it was guides at first. it's not. I've tested valves from the ls7 I'm 100% sure it's the valve. I've seen some valve with know sodium in the valves at all.

z0sicktanner

thanks guys for the kind words, I'm doing my best to help

04_Z06_CE

Thanks for the heads up! Great stuff

Vette @ 71

Are you saying a valve or several of these Sodium filled valves have been observed to have no Sodium?

Trying to understand your points but I am having difficulty following..

z0sicktanner

Yes I have seen one with No sodium in the valve none. once the valve head is welded on thats it..gm gets them and install in the head. sorry for the difficulty call richard at wcch if you can.

Mark2009

Since the sodium is what transfers the heat from the head to the stem, wouldn't a valve with no sodium have a cooler stem?

z0sicktanner

No the soduim is to reduce heat because the valve is hollow it would be like taking a torch to a hollow valve and a solid one and see which one melts first

Jawnathin

My guess is that it would result in an overall hotter valve and possibly parts of the stem.

The point of the sodium was to take heat away from the seat of the valve, distribute it throughout the stem, and then out through the guides and whatever else.

Without the sodium, you have less effective heat transfer out of the valve resulting in a hotter valve and probably the lower parts of the stem. Possibly too hot causing the galling and burnt marks we've seen. All that heat and energy is now in less mass and has less distribution than there would be if there was sodium. The end result is a valve that is hotter and has less effective ways of getting rid of that heat, a self inflicted wounding cycle.

This is like suggesting an engine without that pesky hot coolant will run cooler. Sure, at some point a specific component may be cooler but the rest of the system isn't going to be happy.

z0sicktanner

well said

Mark2009

Good analogy which proves the earlier part of your post incorrect.

The sodium acts as a coolant, transferring heat from the head of the valve to the stem (and thence to the guide, assuming the guide clearance is within spec).

Without the coolant (sodium), the head is hot, the stem is cool (respectively). With it, those extremes in temperature are balanced somewhat.

And therein lies the problem with replacing the sodium valve with any non-sodium version.... heat is going to be left in the combustion chamber and valve seat. Heat that the GM engineers clearly wanted removed from that area (otherwise they would not have used a sodium valve).
.

Jawnathin

Not sure how it disproves what I mentioned earlier.

I think we agree the sodium acts as a coolant, but why do you think the rest of the valve stem will remain cool without the sodium? Even without the sodium the heat transfer will continue, just in a different format.

I suggested that parts of the stem may be too cool (top) and other parts may be too hot (lower) without the sodium. The sodium would have normally helped distribute it across the whole step so it is even, but without it, there would be a large variance across the length of the stem.

It isn't all or nothing like you seem to have suggested.

Additionally with less mass to contain the heat and a less effective way of distributing it, the stem would be hotter overall.

Here is an example, and without a measurement, I just made these numbers up, but something along these lines.

With Sodium
Valve Head - 2300F
Lower 1/3rd of the stem = 1700F
Middle 1/3rd of stem = 1500F
Upper 1/3rd of stem = 1300F

Without Sodium
Valve Head - 2500F
Lower 1/3rd of the stem = 2300F
Middle 1/3rd of stem = 1900F
Upper 1/3rd of stem = 900F