Sodium Filled Exhaust Valves...

Discussion of the 331-354-392 HEMIs.

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Rob
Posts: 208
Joined: Thu May 05, 2011 10:15 pm

Sodium Filled Exhaust Valves...

Post by Rob » Tue May 17, 2011 9:32 pm

Howdeeee. I would like to get opinions about running the sodium filled exhaust valves. I am going to build a warm street motor....my goal is an honest 300 HP. Nothin crazy. Just somethin to cruise and have fun with. They are in excellent condition. As are the seats and guides. I know beyond a shadow of a doubt that a simple coarse and fine lapping in will be all that they need. All I have heard negative is that the larger stem affects flow somewhat. At my HP level, I ain't seein it. So is there any other reason not to run them? My thinkin is as long as they are good, use um. I mean heck, they were sodium filled to allow extra cooling under high exhaust temps while pulling heavy loads....seems to me that kinda goes hand in hand with a HP engine. Also, what about the exhaust rotators? Should they stay or go? I've always chunked um in other applications, but I have never run sodium filled valves, either. Thank you for your time.

mart
Posts: 536
Joined: Tue Mar 22, 2005 2:06 pm

Re: Sodium Filled Exhaust Valves...

Post by mart » Tue May 17, 2011 10:54 pm

If the valves needed replacement, I'd say chuck 'em, but since yours' sound like they're in excellent condition - and also, since you're only planning a mild street build, I'd say keep 'em and run 'em. As for the rotators, the truck engines used them, but there's no reason that they're needed that is specifically related to the sodium-cooled valves, so you could safely lose those.

mart
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Rob
Posts: 208
Joined: Thu May 05, 2011 10:15 pm

Re: Sodium Filled Exhaust Valves...

Post by Rob » Tue May 17, 2011 11:04 pm

Thanks mart. I will be adding some good pictures soon as I get everything cleaned up. Gonna take me a bit cause all I got is a five gallon bucket of carb cleaner. Can only do half a head at the time and then I'm gonna bead blast um after that. Gotta do all to it that I can since I'm on such a tight budget.

johnny5
Posts: 128
Joined: Mon Dec 05, 2005 3:52 pm
Location: St Charles, MO

Re: Sodium Filled Exhaust Valves...

Post by johnny5 » Thu Aug 11, 2011 10:02 pm

my very old service manual states:

if there are any visible cracks in the valve, dig a deep hole in the ground and bury it

no kidding. that was the way they suggested to dispose of it. that's because sodium 'explodes' like a grenade when in contact with water. get rid of them.

George
Posts: 645
Joined: Wed Aug 25, 2004 4:12 pm
Location: Fl

Re: Sodium Filled Exhaust Valves...

Post by George » Fri Aug 12, 2011 4:19 pm

johnny5 wrote: no kidding. that was the way they suggested to dispose of it. that's because sodium 'explodes' like a grenade when in contact with water. get rid of them.
Never seen what happens when a normal valve breaks going down the road, but I saw what happens when a sodium valve turns loose. Grenade explosion covers it.

budmspeeco
Posts: 133
Joined: Tue Dec 21, 2004 5:35 pm
Location: South Houston, Texas

Re: Sodium Filled Exhaust Valves...

Post by budmspeeco » Tue Aug 23, 2011 4:35 pm

Two reasons for pro; "1" - You are the one footing the bill. The first "con" person to step up & buy a new set of solid stem valves for you would be the first opinion I would take seriously!!! "2"- If the stems, valve faces, margins, and guides are in good shape, use them. Another misconception naysayers may have is they are heavy. I weighed some bad ones I replaced a while back & they were actually lighter than the stainless replacements I installed. Chevrolet started using sodium filled valves in their high performance engines in the 60s. I don't recall ever seeing or hearing of one breaking with grenade-like consequences. I don't think you will be twisting this one near as high as a DZ 302 was used to. My too pennies worth. Buddy
'48 anglia

392heminut
Posts: 488
Joined: Sat Nov 30, 2002 2:16 pm

Re: Sodium Filled Exhaust Valves...

Post by 392heminut » Wed Aug 24, 2011 8:29 am

budmspeeco wrote: "2"- If the stems, valve faces, margins, and guides are in good shape, use them. Buddy
I did that with my 392, but they weren't sodium filled valves. Started it up one day in the shop and now I have a piston on the shelf in my den with a pretty good sized hole in it! I will never ever use 50 year old valves in a rebuild again!
Owner of the Poor Man's Hemi Cuda

Rob
Posts: 208
Joined: Thu May 05, 2011 10:15 pm

Re: Sodium Filled Exhaust Valves...

Post by Rob » Wed Aug 31, 2011 1:37 am

Well I have decided to replace all of the valves with new stainless ones. I am going to have some money in this and the last thing I want is a nice engine destroyed by a 55 year old valve that should have been replaced. It will slow me down a tad, but since this is a long term project anyway, what difference does it make?

mart
Posts: 536
Joined: Tue Mar 22, 2005 2:06 pm

Re: Sodium Filled Exhaust Valves...

Post by mart » Wed Aug 31, 2011 9:11 pm

If you're going to change the valves, while your at it, you may as well upgrade from the stock 331-354 1.94 intake valve to the slighter bigger 2.00 inch-diameter 392 intake valve. They're only .060 bigger but that's enough to make a noticeable difference in power. Plus,the cost for aftermarket 392-size intake valves is probably the same - or maybe even cheaper, because they're more common - than for the smaller 1.94 intake valves anyway. - mart
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mart
Posts: 536
Joined: Tue Mar 22, 2005 2:06 pm

Re: Sodium Filled Exhaust Valves...

Post by mart » Thu Sep 01, 2011 11:25 pm

Hey Rob - if you're looking for stainless steel replacement valves, check this out
mart
--------------------------
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SI Industries Stainless Steel Valves
Application:
Chrysler Hemi 354/392
Intake Valve Head Diameter: 2.000"
Intake Valve Overall Length: 5.095
Exhaust Valve Head Diameter: 1.745
Exhaust Valve Overall Length: 5.060"
3/8" Stems
Stock style Multi groove locks
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Description: New set of 16 (8 intake, 8 Exhaust) Stainless Steel Valves. Premium quality Stainless Steel forgings, Chrome stems, Hardened Stelite tips and swirl polishing. Ideal for both High performance street and competition use. Unless otherwise stated all valves are made of 21-4N and EV-8 Stainless Steel, superior to any material used by original equipment manufacturers.
We can also sell you intake or exhaust valves only. We can also supply Bronze valve guides for many applications, contact us for price and availability
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