exhaust valves.....

[oblark]

I found a article on VS that was go on about the difference between N/A & turbo exhaust valves.

The articke mentioned that the turbo exhaust valves have sodium in them, I`ve tried searching to confirm wether this is correct.

Can anyone on here throw some light on this subject ?

[claymore]

I would be surprised if they didn't, even the old metro turbo had sodium filled exhaust valves.

[jamesy12345]

Volvo 460 turbo did (have sodium filled exhaust valves)

better heat dissipation but weaker, or something like that

[merc85]

Yes they have sodium valves, hence they can break up easy

[oblark]

The head on my project engine I`ve been told is a N/A head.

I`ve checked the book of lies and the turbo exhaust valves are a different stem diameter to the N/A valves.

I`ll check the stem diameter this week, If the head is a N/A head it`s going on a turbo block !!!!!!

[960kg]

Yes also they have always had sodium filled valves on the Volvo Turbos but being Volvo they don`t break up easily unless abused by the stupid or tight fisted owner that will only use 95 ron fuel!

Burnt exhaust valves all over the place in the USA because of dirty fuel and also the price of 98ron over here causes owners to use the cheaper dirtier fuel which the T5 is not designed to be run on for long periods of time.

91/92 or 95 ron just for emergencies.

If one does use 95ron the ECU cuts back the ignition thus preventing damage or detonation which also increases the fuel consumption and reduced performance so why own a T5!

[960kg]

Vadis pic.

[oblark]

Abit of a long shot, but can anyone tell me if this is a N/A or turbo head ??

[Wobbly Dave]

As the son of a chemistry teacher & being fairly aware of the dangers of sodium - it appears I have learned 2 things. They really do fill valve stems with sodium & sodium metal still explodes on contact with water.



Guess its ok until you expose it to H2O - and that goes for fast breed nuke reactors too.

[jamesy12345]

Abit of a long shot, but can anyone tell me if this is a N/A or turbo head ??

According to this Swedish breakers site, that is a turbo head. I thought they were the same anyway apart from valves & cam

http://en.bildelsbasen.se/?link=list...ry=1001524 P04

Third one down

[oblark]

According to this Swedish breakers site, that is a turbo head. I thought they were the same anyway apart from valves & cam

http://en.bildelsbasen.se/?link=list...ry=1001524 P04

Third one down

I checked the 2.5 N/A engine in the garage and it had 1001525 PO3

And according to the web site on your post its a 2.5 N/A head

I`m still going to double check the valve stem dia

[jamesy12345]

I checked the 2.5 N/A engine in the garage and it had 1001525 PO3

And according to the web site on your post its a 2.5 N/A head

I`m still going to double check the valve stem dia

oh right hope I didn't post BS & mislead u. I can't see anything more useful on the net

Valve guide diameter should be 12.0 - 12.2 mm?

[oblark]

The information you posted was spot on I was just confirming the casting numbers mean something.

The valve dia is 8-9mm off the top of my head

[artfulflounder]

Sorry if i'm completely off the mark but thinner valves only came into effect '99 onwards I think.

[jamesy12345]

Sorry if i'm completely off the mark but thinner valves only came into effect '99 onwards I think.

My info from here.....

http://www.volvoclub.org.uk/tech/ser...cyl_vin_57.pdf

[960kg]

The inlet valve stem size is the same for turbo or non-turbo but the exhaust non- turbo = 6.955 to 6.970mm
.................................................. .................................................. ....and turbo = 6.945 to 6.960mm

Up to -1999

...........................................

[oblark]

The inlet valve stem size is the same for turbo or non-turbo but the exhaust non- turbo = 6.955 to 6.970mm
.................................................. .................................................. ....and turbo = 6.945 to 6.960mm

Up to -1999

...........................................

The imformation I`ve got on the valve stem dia is

Non turbo 6.955-6.970
turbo 6.810-6.960

[960kg]

Not arguing at all .....but your figure of 6.810 - 6.960 gives the exhaust valve a tolerance to fit of TEN times that of the non turbo = 0.15".......15 hundreds of an inch

Where non turbo exhaust valve 6.955 - 6.970 = 0.015"......15 thousands of an inch tolerance to fit

The inlet valve has the same 0.015" tolerance to fit as the exhaust but the exhaust as it runs hotter is smaller diameter to start with.

If you open your micrometer to 0.015" then open it to 0.15" you will see what i mean!!........0.125" is 1/8 of an inch ........0.15" is more than 1/10 of an inch......the valves may go up and down sideways at that fit!

[oblark]

Not arguing at all .....but your figure of 6.810 - 6.960 gives the exhaust valve a tolerance to fit of TEN times that of the non turbo = 0.15".......15 hundreds of an inch

Where non turbo exhaust valve 6.955 - 6.970 = 0.015"......15 thousands of an inch tolerance to fit

The inlet valve has the same 0.015" tolerance to fit as the exhaust but the exhaust as it runs hotter is smaller diameter to start with.

If you open your micrometer to 0.015" then open it to 0.15" you will see what i mean!!........0.125" is 1/8 of an inch ........0.15" is more than 1/10 of an inch......the valves may go up and down sideways at that fit!

The sizes I listed are from the book of lies and if you look at stem dia in the PDF file in post 15 all list slightly different sizes

I`m going to take a exhaust valve out at the weekend and get my dad to measure with his imperial mic

[960kg]

Well, that is spooky .....as i quoted also from Halfords book. So our books are different mine is the dark blue S70-V70-C70 1996-1999 are you the red 850 book?

I never call Halfords the book of lies as with all information it can vary just like as you say the .pdf file in the link does......there sizes are the same for both valves but it states clearly turbo engine!

I do think Halfords does give good information......even Volvo produced Vadis is full of errors, one just has to suss out with your own logic!

As you know being a practical man, always find out your self and never rely on hearsay as it can drop you in the £££££e.......take one out and measure it against a known sodium filled exhaust valve.