NG headwork - carbon deposits

[Kim Johnson]

Hello Ben,

Just finished this job on my 20V.

I found a 5 minute soak in muratic acid followed by a wire brushing on my
bench grinder was the perfect combo. It took two applications to get the
intake valves shining like new. You can get muratic acid at the local
hardware store. Be sure to wear some protection on your hands and eyes. If
you want to talk about it e-mail me and I will give you my phone number.

As to lapping the valves Sears sell a GREAT tool for doing these for about
$10.00. I was very, very happy with the job that this inexpensive tool did
in seating the valves.

Kim Johnson
1991 90 20V
1986 5ktq (1.8 bar)
others not worth mentioning


----- Original Message -----
From: "Swann, Benjamin R. (BSWANN)" <BSWANN at arinc.com>
To: <JShadzi at aol.com>; "Swann, Benjamin R. (BSWANN)" <BSWANN at arinc.com>;
<quattro at audifans.com>
Sent: Friday, July 06, 2001 12:53
Subject: RE: NG headwork - carbon deposits


> Thanks Javad,
>
> Since the valves are out now and I'm already 1 step from putting in new
> seals, I'd prefer not to take this to a machine shop.  How would they
remove
> the carbon from the valves.  Is there some kind of solvent.  I don't mind
> using an abrasive, just I don't want to do more harm than good.
>
> I wish I had a metal lathe, but perhaps I can put these in the drill press
> and carefully clean them by spinning.  I was just going to hand lap the
> valves in place.
>
> Basically, I'm trying to do this all myself.  If I wanted to I'd just go
buy
> a performance motor, or even a new car.
>
> This project started over a year ago and I will just keep moing ahead at
the
> snails pace 'til I'm finished.  Well right now I'm trying to be a fast
> snail.
>
> Thanks again.
>
> Ben
> '85 4000csquattro - project GTQ moving forward again.
>
>
> -----Original Message-----
> From: JShadzi at aol.com [mailto:JShadzi at aol.com]
> Sent: Friday, July 06, 2001 10:47 AM
> To: BSWANN at arinc.com; quattro at audifans.com
> Subject: Re: NG headwork - carbon deposits
>
>
> Ben, you are right, the valves don't really need to be unshrouded.  As far
> as
> the carbon deposits, it wouldn't be a bad idea to take your head to a
shop,
> for about $150 they can clean up all the valves, lap the seats, and put in
> new valve guides and seals.  This would be a really good idea, especially
if
>
> the head has over 100k miles.  Personally, I would want those deposits off
> the valves.
>
> As far a porting, one of the best tricks I know of, esp. on the NA cars
(the
>
> turbo cars need all the valve seat surface they can get) is to have 1.5mm
> machined out of the ID of the valve seat, which can effectively be like
> putting in 1.5mm bigger valves.  I always go inside the bowl areas and
> smooth
> them out, and the nub that supports the valve guide can be brought down on
> the sides to make it more elongated when looking from the top.  The "short
> side radius" (where the valve port turns 90 degrees or so) can always use
> work in smoothing, often there are sharp edges here from machining of the
> head originally.
>
> The exh. port turns exactly 90 degrees to go to the manifold, I always
spend
>
> a lot of time on the SSR here and often it can be a sharp 90 degree bend
> here!  Then, overall smoothing of the ports, I like to finish everything
off
>
> with 200 grit, you don't want any of the area AFTER the injector to be
shiny
>
> smooth, a little tumble will help atomize the fuel.  Port matching the IM
to
>
> the head is probably the biggest gain to be had, and of course, the IM can
> always be polished and opened up more, at least get the 1/8" of grease
that
> I
> always find in there!
>
> HTH, let me know if you have Q's about specific areas.
>
> Javad
> www.80tq.com
>
>
> In a message dated 7/6/2001 6:29:04 AM Pacific Daylight Time,
> BSWANN at arinc.com writes:
>
> << Any tips on porting or polishing for this specific head would be
>  appreciated.  I understand from previous posts, that the valve  seats
don't
>  need to be unshrouded.  I'm not looking to remove much material, only to
>  clean up some casting imperfections, mostly on the manifold side.
>   >>
>