bracketshark

I just bought a set of 243 heads, was told they were from a 02, z06. the springs have a blue stripe on them, how can I confirm they have the sodium filled valves? I ended up getting them for $600, did I shoot myself in the foot on these?

thepitstop2010

I know the weight will be different and I believe they are longer also. Not sure on exact weights and measurements. Hopefully someone will chime in with some numbers.

lucky131969

You'll have to pull an exhaust valve and weight it. 2002 LS6 exhaust valves were reported to weigh ~63 grams.

dblerman

I thought 02-04 had yellow springs and 01 had the blue springs?
Do you know if the heads you got had upgraded springs?
The only way to be positive I guess would be to weigh the valves.

bracketshark

I figured you'd know..... Was the exhaust valves the only one to be the sodium filled? Did i pay too much? Thanks

thepitstop2010

Yes, the intakes were hollow

dblerman

$600 is on the high end...I see them go for 400-475 all the time in the c6 for sale section...I don't think the sodium valves are worth an extra $150-200 to be honest.

lucky131969

Yes.

If they came with upgraded aftermarket springs, I'd say you did well. If they have stock springs, which are particulary known to break on 02's.....I'd say that's a little steep for my blood.

Tron Z

The sodium helps to keep the head of the exhaust valve cool, by conducting heat away from the head and down the stem. This is not necessary for the intakes, since a) they are not subjected to the same temperature extremes and b) the incoming charge provides a cooling effect.

AU N EGL

intake valves are hollow

also the light wt valves are good for up to 7200 rpms with out valve float

the stock valves or even Stainless Steel valves have a max ~6500 rpms, but still may experience valve float above 6500 rpms

These rpm ranges is were a cam with a max of .575 really produces.

NukeC5

Dont feel bad about what you paid. Its normal for real LS6 243 heads to go for that much. But if they are normal 243 head, the seller took you. If you weigh the exhaust valves at 63-65 grams they are sodium filled. around 88 grams and they are not.

(Not to argue with Lucky at all, but 63 and 88 grams are the specs I have wrote down). These are just weights that you might see.

bracketshark

Thanks, I'll post the weight later. I wonder how much extra spring pressure would be required to overcome the weight difference.

lucky131969

I show 86 grams on regular 243 head exhaust valve, but that was a 2001 comparison, and all my information was from 10 years ago, so I actually had to dig it out.

I would not think of arguing with you, based on your extensive automotive experience.

NukeC5

Im not sure what the actual weight is because I have not weighed a set myself. I just collected that info from an LS1Tech board at one point. Any weight he does get will be close enough to tell whether or not they are sodium filled or not.
I was just giving another possible weight he might see, yours may be what he comes up with. Then I will alter my specs.

OP: Ill be interested to see what you come up with.

SteveDoten

I've got some cracked in half; please note this thread states either or both valves are hollow.

best way is to measure on scale.

The Wrench

The 243 valve stems are 0.024" longer than other LS valves, and it's all above the spring keeper. So, theoretically, You might be able to compare the 243 with a std head without removing a valve. You could eyeball or measure the distance from the top of the valve spring keeper to the top of the valve stem and compare, looking for the .024 longer stem on the 243. But removing and weighing a valve seems pretty easy and more difinitive.

DG

ZeeOSix

See page 5 of the linked PDF .. it says:

"The ’01 intake weighed 99 grams but the ’02 weighs
only 76. The ’01 exhaust weighed 86 grams but the ’02
exhaust weighs 63 grams. The exhaust stems are
filled with a 78% potassium/22% sodium mix to help
cool the valve."

http://www.cadillacfaq.com/faq/answe...-article-2.pdf

The other LS6 (Part 1) write up by Hib Halverson:
http://www.cadillacfaq.com/faq/answe...s6-article.pdf

MY03C5Z

I would recommend replacing the springs with a new set of LS2 blue springs before you install them. Not sure what springs you have on there with a blue stripe. New LS2 springs are only $75 from GM, worth the peace of mind IMO, springs failing seem to be the most common cause of engine failure on the LS6.

bracketshark

You already know the answer, 88 grams on the exhaust valves. Damit, and to top it all off the more I look at them I doubt they came off of the same motor. one head is a lot cleaner than the other and the valve looks fresher also.

NukeC5

So they are basic LS2 sylte heads then? That sucks, still know where to find the seller?