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Looking for 39mm Sodium filled exhaust valves

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deadken

Member
Joined
Mar 31, 2009
Location
Long Island, NY
I have a 531 head at a local machine shop that has a good reputation. While discussion what can be done, we talked about installing 39mm exhaust valves instead of the stock 38mm valves. The machinist likes this idea as it could be done while retaining the stock valve seats and should help exhaust flow. The price is reasonable for the work ($10 a valve), but the question is where to find a 39mm Valve, sodium filled if possible? I have found some listings by searching around the internet, but none of them seem to list the valve size. They all give application (year, make, and model) rather than dimensions. So, I wrote an email to TRW / ZF and I'm awaiting a response.

Figuring that I don't need to re-invent the wheel, I figured that I'd ask here what valves others have used. I realize that it's probably a very small percentage of the users that have done this, but I also realize that of the Volvo owners that have done this, a rather large percentage are likely members here! Thanks in advance for any helpful or humorous suggestions!
 
When my machinst installed larger exhaust valves. He told me 38mm was the largest he would go safely using the stock seats. He had 38mm inconel exhaut valves made and installed them. It will be cheaper to just have the inconel valves made in the size that you need than to find sodium valves that fit.
 
Machinist doesn't own a set of "very-nears"???

Cause it he did he know and then he can tell you that the stock exhaust valve dia ain't 38mm...
Personally I believe it should be the stock size and it is LONG ESTABLISHED that it is safe to put 38mm on the stock seats....

But it isn't 38mm stock...

Next.

38mm is fine

Next.

Sodium filled is meh...Bazillions of higher stressed than limp-dick lame ass Volvo turd-boats went quadrillions of miles just fine without sodium filled valves..

Worry more about matching shaft finish/material to guide material..correct stem length and correct seat pressure on the valve springs.....

But if your machinist can talk about this "1mm up from stock "38"" which is not 38, and sodium filled blah blah...Either he's over 75-80 years old and just pat him on the shoulders, or he's a BSer..or confused but either way run away.
 
When my machinst installed larger exhaust valves. He told me 38mm was the largest he would go safely using the stock seats. He had 38mm inconel exhaut valves made and installed them. It will be cheaper to just have the inconel valves made in the size that you need than to find sodium valves that fit.


Except it is the height of folly...Nobody here in turbobricks is even halfway to making the kind of power that would make inconel valves a worthwhile investment..

As kindly as i can figure out how to say it in the face of such overkill: get real
 
upgrading from the 35mm valves to 38mm will see you a gain. As already pointed out factory was never 38mm and no need to bother with sodium filled valves
 
Except it is the height of folly...Nobody here in turbobricks is even halfway to making the kind of power that would make inconel valves a worthwhile investment..

As kindly as i can figure out how to say it in the face of such overkill: get real

They are a worthwhile investment if you want to build a long lasting powerful engine which was my goal when upgrading from the stock valves to the 38mm ones. Plus the upgraded valves were cheaper than even the stock 35mm sodium filled valves.

Nice try at trolling my post though.
 
They are a worthwhile investment if you want to build a long lasting powerful engine which was my goal when upgrading from the stock valves to the 38mm ones. Plus the upgraded valves were cheaper than even the stock 35mm sodium filled valves.

Nice try at trolling my post though.

It wasn't trolling sensitive little whiner boy..They are ridiculous overkill..talk to an honest engine builder and tell him you're building a 600 HP 8v redblock and ask them if they're "NEEDED"....I have and my head guy I've worked with for 35 years giggled..He builds plenty of Pro-stock and fuel drag motors, he know what makes power and what is needed..
He giggled.

In your whining and crying you just skipped right over the valuable part: neither you or your adviser managed to measure what stock is....
How can that be?

Grow up and quit accusing people of trolling when you write crap that is based on a flat lousy initial presumption. (If you can't even bother to measure the stock valve and see its size, that then discussion of should you upgrade to 39 inconel is certainly based on equally presumptive assumptions..
You also missed in your simpering crap the friendly and actually useful advice about stem to guide material compatibility---if you want a long lasting engine period much less a powerful one..

Chip off your shoulder yet?:roll:

You're welcome.
 
I'm not sensitive. If you are gonna be a D**k GTFO.

What constructive anything thing did you add? Other than criticising my suggestions without any knowledge of what I was doing? The very same thing you complain about .

GO AWAY.
 
I've got no clue about Volvo valve stem sizes, but maybe cut down LS9 exhaust valves?


39mm = 1.535"
 
I'm not sensitive. If you are gonna be a D**k GTFO.

What constructive anything thing did you add? Other than criticising my suggestions without any knowledge of what I was doing? The very same thing you complain about .

GO AWAY.

You are the reason Turbobricks performance section is a ghost-town...
I a) alerted you that you don't know what size valves are stock
b) altered you you head guys could not be troubled to know what size is stock
c) and that he was too lazy/incompetent/stupid to look up what size is stock and what can fit on the seats without the added expense and bother of changing all your seats for not measurable or perceivable benefit...knowing he has not bothered to check that makes any thinking person wonder how he would explain the extra expense if you somehow found valves.
d) alerted you that inconel is ostentatious overkill and dreaming
e) suggestion paying attention to stem finish (hard chrome, nitriding etc) to guide comparability....if you want long term life (hi performance or not)
f) suggested checking seat pressures---Mitsubishi 4G63 valve springs being an excellent spring dor 8v reblocks...no ridiculous titanium retainers needed--unless revving way past 10,000 rpm
g) and mainly I helped you understand what a ignorant twit you are when you answer all those helpful things by calling me a troll..

I don't need to know your plans and since you didn't say anything evidently they're not important...but that doesn't alter all your and your head guys assumptions and errors and omissions...
I'm glad you aren't sensitive, that's so annoying when you take the time to help people and just because they are whiny f**ktards they get angry when you point out their assumptions and start telling people to go away...

Oh wait.
 
I've got no clue about Volvo valve stem sizes, but maybe cut down LS9 exhaust valves?


39mm = 1.535"

Volvo is 8mm aka .315" Not 5/16----aka .03125"

Any idea of stem dia for that thing? LOA? price? sodium filled?

Are they all titanium? You machined titanium before? single round locks..That means more time and money finding the locks and retainers and setting the length right...And which underhead shape?
And what bit me in the ass when doing some 7mm stem titanium valves for a n.a. Redblock: : what about stem tips life span???
 
Editing for the non-essential parts that break the rules.
It wasn't trolling sensitive little whiner boy..

In your whining and crying

Grow up and quit accusing people of trolling when you write crap that is based on a flat lousy initial presumption.

You also missed in your simpering crap the friendly and actually useful advice

Chip off your shoulder yet?:roll:

You're welcome.
Look in a mirror (if a written tone can be seen in a mirror).

You are the reason Turbobricks performance section is a ghost-town...

g) and mainly I helped you understand what a ignorant twit you are when you answer all those helpful things by calling me a troll..

whiny f**ktards they get angry when you point out their assumptions and start telling people to go away...

Oh wait.
1 week ban.
 
I'd agree that sodium isn't worth chasing, and that inconel isn't necessary (not to say that there's NO reason to use it).

I spent a good portion of the winter on the phone with Ferrea racing having them cut custom valves to install in my RSI stage 2 head. We ended up using LS7/LS9 blanks for one side, and a blank they list for Ducati's on the other.

I have not run it yet, but the final machining and assembly was done by a high end machine shop and they gave everything the A-OK. Below is my invoice for part number references.

y71wqVZh.jpg
[/IMG]
 
I have a 531 head at a local machine shop that has a good reputation. ... The machinist likes this idea as it could be done while retaining the stock valve seats and should help exhaust flow. The price is reasonable for the work ($10 a valve)...
Figuring that I don't need to re-invent the wheel, I figured that I'd ask here what valves others have used. I realize that it's probably a very small percentage of the users that have done this, but I also realize that of the Volvo owners that have done this, a rather large percentage are likely members here! Thanks in advance for any helpful or humorous suggestions!

Is this for an NA or turbo application? How will the engine be used? How many miles do you want to go between head rebuilds? That will really be the deciding factor in Ex valve material.

As others have mentioned, the stock valve size is 35-36mm depending on how much carbon is on the valve :)
38mm diameter exhaust valves are the largest that will fit on the stock seat.

The price of $10/valve to have the head work done is very cheap, sounds too cheap. To get the full benefit of the OS valves, the ID of the seat needs to be opened up to ~88-92% of the valve diameter. This means removing over 2mm from the ID of the ex seat, and then opening and blending the bowl area to match. A lot of shops will just transition the valve angles into the stock seat ID. This is the easy way to do it, but reduces flow over the correct way, as you're still flowing air through a stock sized hole...


Except it is the height of folly...Nobody here in turbobricks is even halfway to making the kind of power that would make inconel valves a worthwhile investment..

Inconel, and other high nickel SS valves, have been around for a long time. They were developed for durability over the long run in engine with high EGTs. Standard SS valves look absolutely beat on a 8v turbo (and hi-po NA) motor with 40k miles. If someone wants to spend an extra $100 on valves to get more miles out of a head between rebuilds, I'm all for it.

They are a worthwhile investment if you want to build a long lasting powerful engine which was my goal when upgrading from the stock valves to the 38mm ones. Plus the upgraded valves were cheaper than even the stock 35mm sodium filled valves.
Bingo.

I've got no clue about Volvo valve stem sizes, but maybe cut down LS9 exhaust valves?

39mm = 1.535"

Of the shelf OS valves will be cheaper and less work overall. If the need is to go Inconel, there's usually a group buy a few times a year through Gary and REV valves.

KL Racing has decent OS steel and SS valves for cheap: https://shop.klracing.se/sv/artikla...lar/200-serien/motor-21/ventiler-2/index.html

And what bit me in the ass when doing some 7mm stem titanium valves for a n.a. Redblock: : what about stem tips life span???

That's the easiest part to fix with Ti valves....
 
One other thing to add, in case a reader has never done this:
You MUST open up the port and seat to get any performance gain. I know it sounds like a no-brainer, but I have seen plenty of big valves obstructing a tiny stock seat/bowl/yadda. One wasn't even bigger at the seat, the valve print was wayyy inboard (motorcycle).
The best approach is to use a one-piece multi-angle cutter on a mill for the seat and just inside, then port as needed. (I like to do final seat cutting after porting in case I booger something, but YMMV)
 
One other thing to add, in case a reader has never done this:
You MUST open up the port and seat to get any performance gain. I know it sounds like a no-brainer, but I have seen plenty of big valves obstructing a tiny stock seat/bowl/yadda. One wasn't even bigger at the seat, the valve print was wayyy inboard (motorcycle).
The best approach is to use a one-piece multi-angle cutter on a mill for the seat and just inside, then port as needed. (I like to do final seat cutting after porting in case I booger something, but YMMV)

100% this.
Here's a big valve RSI head that was originally set up with stock seat IDs. The images are after a rough cut with a multi-point cutter. The shiny part on the ID, is the lip left after the cutter made a full seat cut.

40149639132_a09bbcc0b6_z.jpg


39284034155_ce823fc9fa_z.jpg


I then bored the seat out ~2mm and transitioned it into the bowl (after cleaning it all up).

40149621872_c883c2b26b_z.jpg
 
Increasing valve size also increases shrouding, at what point does un-shrouding become necessary?

Also appears that indexing the ground electrode to the exhaust side would be a benefit to get it out of the flow.
 
Increasing valve size also increases shrouding, at what point does un-shrouding become necessary?

General rule of thumb:
Make a cone that has a 36deg angle from vertical and starting from the edge of the valve. Anything this cone touches up to full lift causes shrouding.
Shrouding effects can be minimized with port biasing.

There's a lot of info in the book linked at the bottom of this article: https://www.musclecardiy.com/cylind...-valve-shrouding-improved-performance-part-9/
 
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