RE: Crazy Idea No.2

["Lewis, Gary M" <Gary.Lewis@West.Boeing.com>]

I believe that the 89 and later MC's had 8.4:1 compression.  Was this
accomplished through the head or piston?  If the pistons are 8.4:1, I
would be looking at 89 and up MC's for more compression.  Putting in
non-turbo parts scares me.  The turbo motors seem to have been built
stouter than NA.  

My .02

*********************************************************************
Gary M. Lewis
1986 5000   CS Turbo 5 Speed   195,000 miles 1.8 bar
*********************************************************************


> Technically, I think it can be done. As I remember VW used oil
> squirters in
> most of their blocks after about '85.  They should have some 8.5:1
> pistons
> (81 mm) that would drop in. Also, I recall VW tuners would update
> their
> early blocks with the squirters and clearance the pistons to work -
> tectonics comes to mind.  As for compression, If 8.5 seems too high
> then a
> few thousandths could be taken off the piston tops. Certainly wouldn't
> want
> to go very high with the CR though and I would plan on some quality
> head
> work to reduce the chance of hot spots  developing.  Valve clearance
> won't
> be a problem - nothing here different than a JT with high lift cam. 
> Personally, I wouldn't consider this option since the extra work
> prolly
> wouldn't be worth the benefits and money could better be spent on IM,
> IC,
> TC.   
> 
> Bruce
> ----------
> > From: HAREST@allenbrook.iix.com
> > To: quattro@coimbra.ans.net
> > Subject: RE: Crazy Idea No.2
> > Date: Wednesday, May 20, 1998 2:31 PM
> > 
> > Other things to keep in mind.  The piston skirts on turbo motor
> pistons
> have
> > been clearanced for the oil squirters.  If you were to put NA
> pistons in
> a
> > turbo block, you'll damage either the pistons, or the oil
> squirters... 
> You
> > may also have a problem with valve meeting the piston tops, due to
> different
> > shapes and different lift and duration between the NA and turbo
> cams...
> > 
> > Food to dissuade crazy ideas from becoming crazy actions.
> > -Stott
> > 
> > 	Harrison wrote:
> > 
> > > I think that the title to this e-mail says it all: CRAZY. Wouldn't
> this
> be
> > > like
> > > sticking a turbo on a NA engine and blowing pistons or connecting
> rods?
> > > 
> > > harrison
> > > 
> > > Tony Lum wrote:
> > > 
> > > > Hey gang,
> > > >
> > > > Has anyone tried increasing the compression of the turbo engines
> by
> > > using
> > > > pistons from NA engines during a rebuild?  Then you could get
> some
> low
> > > end
> > > > grunt and even back off on the boost.  It probably wouldn't pass
> CA
> smog
> > > > anymore, and you would certainly have to remap the fuel
> curve...just
> a
> > > thought
> > > >
> > > > -Tony
> > > 
> > 
>