Which Exhaust Valves have Sodium?

[Walt Fricke]

I'm refreshing a set of 2.2-2.7 heads used on a 2.8 long stroke race motor. Valves are just stock size for these heads. I've decided that between my making too much use of my Snapon valve griding machine (first use for real of it by me), and perhaps a bit too much cutting with the Neway cutters, I've dropped the exhaust valves deeper than is good for the motor's CR. If these valves had been shimmed to Aasco's spec before, I need two extra shims to get the spring height back to that, which means they are sunk a fair amount - perhaps enough to drop the CR. So I am planning to replace the exhaust valves.

The usual advice for race motors of this general size is to use sodium filled exhausts.

EBS sells valves made by AE, and by Schottle. Both have the little dimple in the center of the head that the stock ATEs have. I have seen it mentioned that this dimple shows that the valve is sodium filled.

However, EBS was uncertain about this. And the TRW valves, which for certain are sodium filled, are maybe 3X more expensive.

Are the AE or Schottle exhaust valves of this size sodium filled?

[Two Rivers]

Sounds to me like new valve seats are in order. That kind of cutter is very aggressive.

[Walt Fricke]

New seats may be in the future for these heads. However, I think new valves also may be required, hence the inquiry.

[Iciclehead]

Hey Walt, just wondering if the sodium is really necessary and is it even available any more (other than from Porsche).

I must admit I gave up on the idea when I found that my original from the factory 1979 Euro SC engine did not have them (at least there is no divot on their tops), the spare set of new, sitting-in-the-box valves I bought do not have divots and the new valves that Steve put in my new 3.4 heads did not have divots either. Haven't checked the Kremer, but I do not recall seeing divots on those either...

Basically while my brain says that sodium filled is a great idea, the reality seems to be that they are not typically available any more.....so I just gave up and settled for Steve's recommendation.

...but then again, you race your stuff!

Dennis

[Walt Fricke]

Well, I guess no one knows the answer here.

After grinding 8 used exhausts I got from friends which looked OK, and had a reasonable thickness left after grinding and lapping, and sealed in my test head, I weighed them.

4@88 grams
1@87
1@86
1@89
1@94

The 94 was TRWT3064/3K, and did have the thickest head. I'll see if that is so when I get done measuring installed height, as my plan is to pick the six which are shortest in that regard (I'm just measuring on one head to see how they vary, not setting the height). That should give me the thickest head rims of the bunch.

Now if I can get someone to weigh new aftermarket valves, perhaps that weight will suggest whether sodium filled or not.

[Iciclehead]

Originally Posted by Walt Fricke

Well, I guess no one knows the answer here.

After grinding 8 used exhausts I got from friends which looked OK, and had a reasonable thickness left after grinding and lapping, and sealed in my test head, I weighed them.

4@88 grams
1@87
1@86
1@89
1@94

The 94 was TRWT3064/3K, and did have the thickest head. I'll see if that is so when I get done measuring installed height, as my plan is to pick the six which are shortest in that regard (I'm just measuring on one head to see how they vary, not setting the height). That should give me the thickest head rims of the bunch.

Now if I can get someone to weigh new aftermarket valves, perhaps that weight will suggest whether sodium filled or not.

I can do that.....I have a set of 6 TRW (I think)....

Dennis

[Iciclehead]

Just checked my new spare set of valves....all of them were 106 grams, within .1 gm

I would have suspected sodium filled to be lighter than solid, as the sodium is lighter than steel and basically there is a big honking hole in the steel and it is only partially filled with sodium.

Dennis

[Walt Fricke]

Dennis - interesting.

TRW is, supposedly, an OEM supplier here. If you can measure within 0.1gm, you have a better scale than I do - I have a postal scale which measures to 1gm. And, perhaps because my garage is cold, I found reweighing often produced a change of a gram. But the ballpark is good enough. I'd expect mine to vary some, as they have been ground, and they were more or less decarboned, depending.

I'm pretty sure the sodiums are lighter. Might that mean that your new TRWs are solid? What are the alpha/numerics stamped around the tip?

[Iciclehead]

Originally Posted by Walt Fricke

Dennis - interesting.

TRW is, supposedly, an OEM supplier here. If you can measure within 0.1gm, you have a better scale than I do - I have a postal scale which measures to 1gm. And, perhaps because my garage is cold, I found reweighing often produced a change of a gram. But the ballpark is good enough. I'd expect mine to vary some, as they have been ground, and they were more or less decarboned, depending.

I'm pretty sure the sodiums are lighter. Might that mean that your new TRWs are solid? What are the alpha/numerics stamped around the tip?

Wife has a super duper kitchen scale/digital readout/high end that we bought in Europe, it has a stated tolerance, so I think it is pretty good.

I looked at the stem of the valves and they say TRW T3051/1. These are brand new, not a spot on them. I have a set of intakes from my '79 Euro that are all carboned a bit, did you want me to give them a weigh (it'd take a bit to dig them out)? The carbon would add a bit of weight, but the differential between yours and mine is probably bigger than the weight of carbon.

And yes, I am almost positive the TRW's are solid....the stem end is machined flat and smooth without a mark on it.

Dennis

[Walt Fricke]

Thanks for checking on this.

I think only 935 intakes got the sodium treatment (Inconel for the exhaust). Certainly not our NA motor intakes. Weight only of interest here as a way of trying to tell if exhausts are sodium filled.

My lighter exhausts with TRW markings show T-TRW3064, T-TRW3064 14, or TRW T3064/3K. Since the ATE exhausts also have 3064 on them, or 3064 22 or 52, I am guessing 3064 indicates sodium filling for ATE and TRW.

And 3051 indicates a solid stem.

So I now know if an exhaust of this diameter weighs over 100 grams, it is not sodium filled.

Your wife must be a fanatic cook if she weighs ingredients to the 1/10 of a gram!

[proffighter]

Maybe not useful, but 930 Turbo exhaust valves are Natrium filled...

[Iciclehead]

Originally Posted by Walt Fricke

Your wife must be a fanatic cook if she weighs ingredients to the 1/10 of a gram!

She uses it for spices...heavy into the curry where the saffron (I gather) is pretty pricey and the measurements need to be exact. I think that 99% of her weighing though is for much more mundane things....

D.

[Flat6pac]

3.0 is larger valves than the 2.2 to 2.7, intake and exhaust.
Bruce

[Iciclehead]

To be clear, the valves I have are 41.5 mm diameter...

Dennis

[proffighter]

Originally Posted by Iciclehead

To be clear, the valves I have are 41.5 mm diameter...

Dennis

Same as 930 turbo 76-89...

[haasad]

Its good fun to cut open u/s sodium valves and play garden science...at least my son thinks so.........

[cgarr]

Your not to grind sodium valves? Is this also true for the Porsche valves?

[Walt Fricke]

Natrium sounds a whole lot like sodium (NaCl)?

Craig - I don't recall seeing a factory workshop warning not to regrind the sodium valves. I hope that is not contraindicated, as I have ground all of mine, and have one bank of the top end redone as of today.

[Iciclehead]

As I read it, all the sodium is in the stem and that isn't ground at all....don't see any reason why it was not possible....

Dennis

[cgarr]

I asked about grinding because VW makes a big deal about not grinding their sodium valves, they say to only lap them. I don't know if this is because the height is critical when assembling the head or because of the sodium near the valve face?