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[HEADWORK] Port Match and Polishing



Now you are starting to talk about the real shit, more
power!

Head shaving: in my Bentley Engine and Clutch Chapter,
page 36 Fig 6-13

"Cylinder head resurfacing dimension. Head's
combustion chamber surface can be milled or ground in
order to correct warping or other damage so long as
dimension a (from head gasket surface to cylinder head
cover gasket surface) is not reduced to less than
5.219 inches."

In a stock JH motor doing so will raise the CR about
half a point. The downside is that it becomes an
interference motor. Break the t-belt, and you have to
replace 8 valves, and redo the head.

As far as an 8V JH head matched to an ABA block,
you'll have to do your own math regarding CR. I can't
answer that.

P&P
I am just about to redo some port matchings, I just
need to get off the computer, and into the garage...
First again, check this out:
http://www.sa-motorsports.com/diyport.htm

I am using an air grinder with the above kit. I am
more or less doing a street port matching. going 1.5"
- 2" deep into the port to match with the gaskets.

On the 8V head, all 8 ports have a nasty casting thing
(what's the exact word to use you English fellow VW
nuts?), remove it all the way. 

Also, search the archives, Meze did post a long and
very interesting article about head porting.

While you are at it, port match the intake manifold
for as deep as you can into the runners. One just went
for 150$ on ebay today. It is a joke to do, save some
$$$. And port match yous TB the right way (by welding
metal in the back of the intake manifold, just like TT
does it). Then by grinding the opening.

One last thing, you do have a 4 into 2 manifold (port
matched? yes), and at least a 2" mandrell bent exhaust
system all the way back. Do you?

Remember, aluminium is soft, so be conservative, as
the grinder does cut into it very fast. Use lots of
WD40.

Cheers.

Marc
'83 Scirocco
'88 Scirocco Slegato

 --- ATS - Patrick Bureau <pbureau@attbi.com> a écrit
: > Very Sweet... What did you use to do the P&P on
the
> head, I am about to do
> this on my 8v JH Head, and I have been looking for
> information on what
> materials to use to do this (BY Hand or mechanical
> means?)  0.40" shaves
> eh..? thats a lot indeed... I have thinking of
> sending mine out to be shaved
> 0.20" (to push the compression from 10:1 to
> 10.5/11:1 maybe, what kind of
> compression you have now with a 0.40" shave doen to
> the head, I am very
> curious of the results on that !
> 
> ==========================================
> ATS - Patrick Bureau
> 1985 8v "ATS GTX" <- About to embark in ABA/JH
> project
> 1988 16v "ATS 16V" <- For Sale : 1500.00
> Web Site : http://longcoeur.com/scirocco
> 
> 
> =>-----Original Message-----
> =>From: scirocco-l-admin@scirocco.org
> =>[mailto:scirocco-l-admin@scirocco.org]On Behalf Of
> Dave Ewing
> =>Sent: Sunday, April 14, 2002 4:36 AM
> =>To: Scirocco List
> =>Subject: Re: [HEADWORK] Port Match and Polishing
> =>
> =>
> =>I installed a head that I port and polished myself
> last week.  I
> =>didn't take
> =>a bunch off but smoothed things out mostly.   Runs
> very strong and quiet.
> =>The following is what I did:
> =>
> =>1.  Shaved head 40 thousandths  (the MAX for
> shaving a 16v head without
> =>having to move the tensioner stud--I can flip the
> tensioner all the way
> =>over!!!)
> =>
> =>2.  New intake valves, exhaust valves, and valve
> guides.
> =>
> =>3.  Exhaust cam on intake side which creates an
> asymetrical cam set and a
> =>nice lumpy idle but not radical.  Have heard that
> this is similar
> =>to a 268?
> =>I might, and probably am, wrong but I measured the
> lobes and the exhaust
> =>lobes were much bigger over all and longer
> duration.
> =>
> =>4.  2.0L cam gears for quieter chain operation.
> =>
> =>5.  Adjustable cam sprocket--almost a necessity
> for shaving the head so
> =>much.
> =>
> =>6.  Autotech HD springs.
> =>
> =>7.  Ground vave seats.
> =>
> =>8.  Deshrouded valves.
> =>
> =>9.  Slight combustion chamber polish.
> =>
> =>10.  Minor port and polish.
> =>
> =>11.  2.0L 16v head.
> =>
> =>12.  STOCK TIMING BELT ADJUSTER STUD!!  I
> installed the head with the
> =>adjuster on the stud so I didn't have to pull the
> stud to install the
> =>tensioner.  From now on, I will jack up the motor
> to replace this
> =>so I don't
> =>wear out the threads in the head.  Heck, it's only
> time and I have more of
> =>it than money!!
> =>
> =>I like this setup and feel it flows nicer and
> smoother than the
> =>P/P 1.8 head
> =>with euro cam.  I still need to play with the
> timing a little since I
> =>adjusted it advanced because of the increased
> compression and cam
> =>setup and
> =>still don't get even one ping so I think I might
> need to play with the
> =>adjustable cam sprocket a little.
> =>
> =>Check out pictures of the head not installed here:
> =>
>
=>http://pages.prodigy.net/dcewing/_uimages/2.016v1.JPG
>
=>http://pages.prodigy.net/dcewing/_uimages/2.016v2.JPG
>
=>http://pages.prodigy.net/dcewing/_uimages/2.016v3.JPG
>
=>http://pages.prodigy.net/dcewing/_uimages/2.016v4.JPG
> =>
> =>These weren't the final product but it was nice to
> be able to
> =>take pics then
> =>shape and smooth more accurately after looking at
> the pics.
> =>
> =>Dave


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