the difinitive prechamber size thread

[NintendoKD]

Ok, so I stared this thread in the hopes that it could be added to the faq, in the way that others may use the information therein.  It occurs to me that precups are becoming more and more dificult to come by, and there must be a solution, however, until that solution is discovered, we are stuck to using precups from another head, USED.  Willl this fit that, that sort of thing, will 1.6 N/A fit AAZ? will 1.5 fit 1.6 Turbo?  what are the dimensions and gains/losses of said swaps.  There is a lot to be learned gents so please pipe up.

thanks,

Kevin

[MRTANGOMAN]

Check this site out
http://www.eurocartogliani.191.it/EN-FrameBase.htm

looks like the N/A and TD 1.6 are the same, the 1.9 and 1.5 are both different..

[MRTANGOMAN]

ok some sizes in mm
                                                width @ head face      width inside head       height of the flange
1500 diesel (oem p/n 068103391)          30                            25.35                         3,75
1600 n/a td (oem p/n 069103391)         32                             27.3                          4
1900 n/a                                           30                            25.35                         4
1900td       (oem p/n 028103391m)        32                            27.8                          4


ALL MEASUREMENT TAKEN FOR THE WEB SITE LISTED IN MY POST ABOVE!!
THESE ARE FOR REFERANCE ONLY , ANY MISTAKES, NOT DOWN TO ME

[NintendoKD]

thanks tango, this should be very useful to many here on the forum.  any way you could get pictures for comparison?  or pictures period, there may be other differences that are pertinent.

[maxfax]

IIRC, someone once mentioned that there is a difference in the cups between the hydro and mech heads. I don't recall what this difference was supposed to be, but I recall this coming up at one point...

[rabbitman]

I "quick" search showed this: http://www.vwdiesel.net/forum/index.php?topic=20075.0

http://www.vwdiesel.net/forum/index.php?topic=20672.0

There's a lot more but lots of the info is contained in some loooooooong threads

[NintendoKD]

hence the nice, short, thread with up-to date information.

[NintendoKD]

I agree, does someone have access to the 1.5 1.6N/A 1.6 TD and 1.9 cyl heads as well as the L5 audi/VW head then we can get some real answers.

[Rabbit on Roids]

i have 1.5 cups, 1.6 n/a cups 1.6 TD cups, and audi 2.0 5 cyl cups.. what measurements do we need?

[NintendoKD]

actual cc containment, diameter both at the bottom and at the lip, in other words, to find out if the prechambers can be exchanged from one head to the next.

thanks ROR,

Kevin

[Rabbit on Roids]

i have no way to CC these things, unless its with water and a graduated syringe.. and thats just going to be a close measurement. i have a set of standard calipers. nothing beyond that really.

[745 turbogreasel]

I know on the GM diesels, the port varies in shape and size by application as well.

[NintendoKD]

maybe there is a tech page somewhere that lists the cc containment no's but the depth and diameters, as well as other dimentionL details will be very helpful in this thread maybe one of our senior members can assist with this.  Maybe a Machinist? Jedi Master Giles?

[Rabbit on Roids]

I know on the GM diesels, the port varies in shape and size by application as well.

on GM's the n/a J-code heads have the biggest ports and flow the best in factory form.

[NintendoKD]

Thats interesting. I've computed the following from engine data tables:

1.5 Swirl chamber volume 11.457 cc

1.6 Swirl chamber volume 12.794 cc

1.9 Swirl chamber volume 16.376 cc

found this in another thread, thanks krautster