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Engine Specific Info and Questions => IDI Engine => Topic started by: Turbofan on April 06, 2012, 03:55:56 pm

Title: Turbo vs NA Cylinder Heads
Post by: Turbofan on April 06, 2012, 03:55:56 pm
I'm planning on replacing my HG soon (with an AAZ and some ARP's) and I'm anticipating tgat my head is cracked in between the valves for several reasons. If I'm right, I'm contemplating replacing the head with a rebuilt one. I have a hydro head on my '86, and while I was checking prices, I saw that there were turbo heads too (presumably from the Eco's?). What's the difference? The valve composition? Is it a worth while swap? I have a VNT 17 (cold side from an '02 Saab 95) if I recall. No gov. mod yet. Stock injectors, 1.9 IDI camplate.

On a completely separate note, anyone have any experience with HID kits? I found one that is a bi-beam kit, and includes projector lamps that (I think) will fit my Westy front end. Maybe I should just get some tried and true Euro-beams instead.
Thanks for the help!
Title: Re: Turbo vs NA Cylinder Heads
Post by: theman53 on April 06, 2012, 04:09:26 pm
cracks are normal. TD heads had sodium filled valves.

No idea, but H4 with relays is plenty good.
Title: Re: Turbo vs NA Cylinder Heads
Post by: Turbofan on April 06, 2012, 04:41:55 pm
Thanks. I think the specs are for nickel sized cracks or something? Maybe I can just have them welded. A rebuilt head is like $450, and I know that'll more than pay for a valve job. I'm cheap anyway, so I'll probably go that route.

I'll probably go the H4 route too.
Title: Re: Turbo vs NA Cylinder Heads
Post by: wdkingery on April 06, 2012, 07:31:21 pm
HID's are fantastic; seems you already have a vendor, or i'd turn you on to one. i have some in my mustang, and i'll never go back. i'd like to do the jetta, but .. hell the damn thing doesn't even run right now! but HID's.. especially in a projector i would imagine would be the bee's knees. also, spring the extra coins for the bi-beam. when you hit them highs it's a wonderful thing
Title: Re: Turbo vs NA Cylinder Heads
Post by: mystery3 on April 06, 2012, 10:31:18 pm
HID's are fantastic; seems you already have a vendor, or i'd turn you on to one. i have some in my mustang, and i'll never go back. i'd like to do the jetta, but .. hell the damn thing doesn't even run right now! but HID's.. especially in a projector i would imagine would be the bee's knees.

If you run hid's in a non-projector lamp you are an idiot, not only will you blind everyone else but the scatter will be so bad that you likely won't see any further than with a proper bulb.

As for the head, I'd just have it pressure tested to check if any of the cracks are bad.
Title: Re: Turbo vs NA Cylinder Heads
Post by: billybobf on April 07, 2012, 12:40:07 am
I agree with the pressure test,

I want to make my own pressure test plate for the diesels, flat plate, neoprene, some block off plates and HELIUM. pressure testing with helium is 4 times more likely to show a leak... or will show the same leak at 4 times less pressure then compressed air... just a helpful hint ;)

not certain on the math and numbers. but I used to test chemical lines and the smaller helium molecules would take flow more bubbles from a pin hole then just shop air, and on a regular basis showed pinholes that shop air did not show.
Title: Re: Turbo vs NA Cylinder Heads
Post by: Turbofan on April 07, 2012, 08:02:31 pm
Good stuff guys, thanks! I don't think the machine shop I use pressure tests with helium, but I'll razz them about it next time I go in! Ha! When I first did my VNT swap I think a combination of back pressure and boost did in my head. My clutch used to slip on the highway, now it doesn't at all. Who knows, maybe I'll get lucky and find out that it is just some funky head gasket problem, but I'm still averaging 41 mpg, and since I'm not pressuring up the coolant, and my oil is clean, I tend to doubt it. Only time will tell.  Once I finish prepping my Lemons car, I'll have time to pull the Golf apart.
Title: Re: Turbo vs NA Cylinder Heads
Post by: wdkingery on April 08, 2012, 01:30:27 pm


If you run hid's in a non-projector lamp you are an idiot, not only will you blind everyone else but the scatter will be so bad that you likely won't see any further than with a proper bulb.


yes, yes all of these things. you aren't truly able to see any further, altho where the light does shine is much brighter, and i'm sure i piss off every car i pass, both day and night. i'm sure of it.
Title: Re: Turbo vs NA Cylinder Heads
Post by: R.O.R-2.0 on April 08, 2012, 02:38:15 pm


If you run hid's in a non-projector lamp you are an idiot, not only will you blind everyone else but the scatter will be so bad that you likely won't see any further than with a proper bulb.


yes, yes all of these things. you aren't truly able to see any further, altho where the light does shine is much brighter, and i'm sure i piss off every car i pass, both day and night. i'm sure of it.

Jeremy just put HIDs in his non-hid housings..
Title: Re: Turbo vs NA Cylinder Heads
Post by: billybobf on April 08, 2012, 04:05:49 pm
Hey, back on topic for JUST a second, can you get replacement sodium filled valves? I know when I had my old ford pickup and we rebuilt the heads we put in new guides and standard valves due to cost.

Also, can you put the sodium valves in a mechanical head?
Title: Re: Turbo vs NA Cylinder Heads
Post by: theman53 on April 08, 2012, 04:51:31 pm
Yes, and yes, IIRC TRW makes them or at least 3 years ago I found them, search is your friend.
Title: Re: Turbo vs NA Cylinder Heads
Post by: R.O.R-2.0 on April 09, 2012, 08:35:53 am
Hey, back on topic for JUST a second, can you get replacement sodium filled valves? I know when I had my old ford pickup and we rebuilt the heads we put in new guides and standard valves due to cost.

Also, can you put the sodium valves in a mechanical head?

most definitely, im running an 84 Jetta TD head on my 83 Vanagon engine, and it has sodium filled valves..
Title: Re: Turbo vs NA Cylinder Heads
Post by: Toby on April 09, 2012, 02:48:53 pm
How do you know? Or rather how can you tell they are sodium filled exhaust valves? Any that I have ever seen had rather large valve stems. It would be kind of hard to get a 8mm valve stem to have much strength and still have much sodium in there.
Title: Re: Turbo vs NA Cylinder Heads
Post by: 745 turbogreasel on April 09, 2012, 07:40:58 pm
They  have a different dish in the face.
Title: Re: Turbo vs NA Cylinder Heads
Post by: Toby on April 09, 2012, 08:00:30 pm
And what makes you think the different dish means sodium filled? I have done heads on 4 and 5 banger TDs and never seen a sodium filled exhaust valve on any of those, nor have a ever seen the sodium valve warning in any Bentley manual either. So what year and model supposedly have the sodium filled valves? Every sodium filled valve that I have ever seen had a big stem and was marked as such, and the manuals had the sodium vale disposal warning as well.
Title: Re: Turbo vs NA Cylinder Heads
Post by: R.O.R-2.0 on April 10, 2012, 10:44:08 am
Toby, grab an old TD exhaust (im sure you have 500 laying around) valve, and cut a notch in the valve stem. then throw it in a bucket of water.. tell us if it goes nuts once it touches the water..

i would totally cut a worn out TD valve, but i only have 4 exhaust valves, and they happen to be installed in a TD head right now..
Title: Re: Turbo vs NA Cylinder Heads
Post by: billybobf on April 10, 2012, 07:44:42 pm
you know that in moist air that a sodium filled valve van do some serious damage right?
Title: Re: Turbo vs NA Cylinder Heads
Post by: Toby on April 10, 2012, 09:41:28 pm
I have a set of TD exhaust valves on the bench and they look identical to the regular diesel stuff. So what would make me think they are sodium filled?
Title: Re: Turbo vs NA Cylinder Heads
Post by: bajacalal on April 10, 2012, 10:16:44 pm
Toby, grab an old TD exhaust (im sure you have 500 laying around) valve, and cut a notch in the valve stem. then throw it in a bucket of water.. tell us if it goes nuts once it touches the water..

i would totally cut a worn out TD valve, but i only have 4 exhaust valves, and they happen to be installed in a TD head right now..

I thought the sodium was only in the center of the stem.
Title: Re: Turbo vs NA Cylinder Heads
Post by: R.O.R-2.0 on April 11, 2012, 09:02:41 am
I have a set of TD exhaust valves on the bench and they look identical to the regular diesel stuff. So what would make me think they are sodium filled?

Toby, grab an old TD exhaust (im sure you have 500 laying around) valve, and cut a notch in the valve stem. then throw it in a bucket of water.. tell us if it goes nuts once it touches the water..

i would totally cut a worn out TD valve, but i only have 4 exhaust valves, and they happen to be installed in a TD head right now..

I thought the sodium was only in the center of the stem.

you guys know that water and sodium react right? sodium BURNS when you introduce water..

thats why i said to notch the stem of a valve.. that will expose the sodium, and allow the water to touch it, and react.

i wish someone would do it, and take a youtube video of it..

and i swear ive read somewhere in a bentley that it says to NOT GRIND THE VALVES on a TD, because of the valves being sodium filled?
Title: Re: Turbo vs NA Cylinder Heads
Post by: bajacalal on April 11, 2012, 10:34:07 am

you guys know that water and sodium react right? sodium BURNS when you introduce water..

thats why i said to notch the stem of a valve.. that will expose the sodium, and allow the water to touch it, and react.

i wish someone would do it, and take a youtube video of it..

and i swear ive read somewhere in a bentley that it says to NOT GRIND THE VALVES on a TD, because of the valves being sodium filled?


I know it does. I want to try this. But I think you would have to do more than "notch" the valve. I think you would have to saw the stem in half to get at the atomic sodium. I thought it was pretty well sealed in there. As far as grinding them, I don't know... maybe because they are hollow they are weaker? I don't think the sodium is that close to the surface though.
Title: Re: Turbo vs NA Cylinder Heads
Post by: R.O.R-2.0 on April 11, 2012, 10:37:40 am
when i say to notch a valve, i mean to take a grinder, and cut a notch half way thru the valve stem.. or cut the valve stem in HALF. that will surely expose the sodium.
Title: Re: Turbo vs NA Cylinder Heads
Post by: Trips_B on April 11, 2012, 02:26:51 pm
I will take a look when I get home, I may have an extra valve but im pretty sure they were all tossed when I got rid of my extra head
Title: Re: Turbo vs NA Cylinder Heads
Post by: bajacalal on April 11, 2012, 02:51:17 pm
Other (usually turbo) engines had sodium filled valves, usually exhaust valves.

If you want to do a science experiment just make sure to wear eye protection and to put it on youtube.
Title: Re: Turbo vs NA Cylinder Heads
Post by: Dakotakid on April 11, 2012, 06:18:56 pm
This is why the replacement TRW valves for the hydros are so damned expensive.
Oem TD solid exhausts were sodium from the factory.
Every Bentley I have ever had has this warning in it.
Less argumentation. More reading.
Title: Re: Turbo vs NA Cylinder Heads
Post by: Trips_B on April 11, 2012, 07:36:39 pm
sorry guys, I just went through and cleaned the garage and alas I have no extra exhaust valves to try this