Found new AE prechambers

[wil892]

Having just received a head with cracked chambers I went on the hunt for some new ones. I looked in the Federal Mogul UK electronic catalogue for them and found some for the 1.6td head under the Audi 80 1.6td section. They are for the SB GTD engine and there are two different sizes listed but only one is available in STD size and 0.5mm oversize. My local supplier says he can get them in from Belgium for £12 each. Link: http://www.fmecat.eu/selProd2.asp?make=5&model=%20&engine=4211~SB&litre=%20&prdgrp=4&langID=1&TsVer=&engseal=0
Before I order I'm trying to establish if they will fit correctly, Federal Mogul lists the dimensions which seem to correspond with some measurements taken from this thread:
http://www.vwdiesel.net/forum/index.php?topic=2329.msg17375#msg17375

These are the dimensions in the catalogue of the chambers with part number PCC111:
Outer Diameter [mm]    25.400
Flange Ø [mm]    30.000
Height [mm]    4.300

I have measured the current cracked chambers which are still in the head, and they have a 30mm diameter on the face. Which I assume is the "Flange", so what is the "Outer Diameter", maybe the inner ring?
I can get either standard size or 0.5mm oversize to 30.5mm Flange, I assume this would just mean slightly boring the seat in the cylinder head.
I will get them ordered tomorrow and have them in about 10 days, when I shall do some comparisons of the orginal and new ones. I checked on the same catalogue for non-turbo engines, and there is a different part number listed.
Will

[92EcoDiesel Jetta]

Pull one of your's and measure before ordering?

[rabbitman]

These are the dimensions in the catalogue of the chambers with part number PCC111:
Outer Diameter [mm]    25.400
Flange Ø [mm]    30.000
Height [mm]    4.300

I have measured the current cracked chambers which are still in the head, and they have a 30mm diameter on the face. Which I assume is the "Flange", so what is the "Outer Diameter", maybe the inner ring?
I can get either standard size or 0.5mm oversize to 30.5mm Flange, I assume this would just mean slightly boring the seat in the cylinder head.
Will

I think you're right but best is too pop 'em out and measure, hit it with a wood dowel through the injector hole. If it's stubborn heat the head and try again.

[wil892]

Pulled the prechambers today and measured them. The specs are spot on so I have ordered 4 new prechambers at £15 each including VAT. Not a small amount of money but it means I can use a genuine head!

[Mark(The Miser)UK]

Pulled the prechambers today and measured them. The specs are spot on so I have ordered 4 new prechambers at £15 each including VAT. Not a small amount of money but it means I can use a genuine head!

How easy do they pull out?
Are they then tight to push back in?
Just how strong is a badly cracked one?

I still have the German head from my very first vw diesel. It blew a headgasket, and as a virgin looking at all the cracks on the head, ie between the valves and on the inserts, I naturally assumed that the head itself was leaking.

Time to resurrect perhaps.  Damn I think it was hydro, and my current one is mech

[wil892]

I welded a bolt to each of the prechambers, put a mount over them and used a nut to pull them out the head. They came out smoothly, and didnt suddenly let go. I think most of the interference is the carbon build up. The machine shop said the new ones are pressed in with a little locktite and have to protrude ever so slightly (he gave a figure).

[92EcoDiesel Jetta]

Are the cracked swirl chambers magnetic? I think R.O.R says that Inconel ones are non magnetic and steel ones are. When you get the new ones, please check if they are magnetic or not.

[Mark(The Miser)UK]

I welded a bolt to each of the prechambers, put a mount over them and used a nut to pull them out the head. They came out smoothly, and didnt suddenly let go. I think most of the interference is the carbon build up. The machine shop said the new ones are pressed in with a little locktite and have to protrude ever so slightly (he gave a figure).

Sounds like a little welding of the precup would have worked.
 Even a dab infront of the hairline crack.
Good info.Thanks

[R.O.R-2.0]

Are the cracked swirl chambers magnetic? I think R.O.R says that Inconel ones are non magnetic and steel ones are. When you get the new ones, please check if they are magnetic or not.

yes!

real Inco pre chambers are NOT magnetic..

steel cups came in VERY EARLY diesels, and in aftermarket heads..

i recently dug up a pre-cup from a 1976 1.5D (was from a bare bones car, even had manual brakes) and it WAS STEEL, so VW did use some steel cups in very early engines.. (this engine had NEVER been opened up, since it rolled off the factory. i got it from the 2nd owner, and the original owner was his dad, and had never had the engine open)

my 1980 1.5D has Inco pre-cups tho. and again, its an OEM head.

the cups in my 1.6TD head tho, couldnt get a magnet to stick to them if my life depended on it..

and, for anyone who cares, here is a pretty good article about Inco on Wikipedia.

http://en.wikipedia.org/wiki/Inconel

[wil892]

Sorry this hasn't been updated. I have installed the new chambers in the head now but here are some pictures of them out the packet. They speced out exactly the same as the originals but I forgot to test them with a magnet. I will check next time I can.

[rodpaslow]

I don't know if you still need to mag them, but the ones in my head are very, very easy to tell because they are a slight tan color and don't look like regular carbon steel; By the pictures below I'd say they are not Inconel.  My opinion, I don't think it matters as I had three of the Inconel ones in my OEM vw head that were cracked.  Maybe if you do a lot of WOT driving it would make a difference. 

I've just had my head off and the steel ones look good and were installed over 1 1/2+ years.

[R.O.R-2.0]

those are steel i would say, inco looks more tan because of all the nickel in it..