Heron Pistons and Larger Valves

[Bruce Bell]

Careful...

Those 1588 cc VW's used an 80 mm stroke. If you try to use these
pistons with your WE then about 3.2mm of those piston will be
above the block.  The heron pistons have a very deep dish,
similar to the dish in the WX/WR motors used in the Urq's. I
can't see how the heron could possibly raise the CR.

If you are going through this much trouble use the pistons from
an 85 or 86 GTI/GLI and  bore the block to 81.5 mm. This should
yield you a 10:1 CR. which you can lower by unshrouding the
valves while cleaning up the combustion chamber.

Bruce


-----Original Message-----
From: quattro-admin at audifans.com
[mailto:quattro-admin at audifans.com]On
Behalf Of Alan Kramer
Sent: Monday, December 18, 2000 9:16 PM
To: quattro at audifans.com
Subject: Heron Pistons and Larger Valves


Anyone know the part numbers for "Heron" pistons?  They were used
in the
european 1.6L VW's with the completely flat bottomed heads...
They came in
79.5mm diameter and are now a hot item for VW guys to put in 1.7L
VW 8v
motors (whose cylinders appear to be dimensionally identical to
2144cc WE
code I-5's) to increase the CR up to 9.2:1.

Also, does anyone know if larger valves can be fitted into the
2144cc
engine?  From what I remember last time I looked at the head, I
thought I
could go 2mm larger on the intake.  True?  I figure finding
valves of larger
diameter in 98.7mm length might be difficult...

I'm trying to find a few more horses in my new motor and pistons
and valve
size are the only two things I haven't touched yet...the site
shows what
I've done so far.

Thanks,
Alan

'83 CGT   http://www.geocities.com/audikramer
'86 4kcsq
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