[T3] Mahle 1500 pistons

Fri Sep 7 17:37:08 PDT 2012

Ok, I took out the white gloves and opened my NOS 1961 VW official service
manual.  Looks like there were 9 different sizes available, the standard had
3 sizes, 82.95mm, 83mm, 83.05mm  then there were the .5mm oversize that cam
in 3 incriments too and the 1mm oversize and again, 3 incriments.  The
incriments were color coded.

Looks like I have the smallest pistons, the 82.95mm blue code.
They are stamped on the crown, SP 0,05mm and I don't know what that means
but I inserted them in the barrels and they are the same size as the
original domies, or damn close, certainly not .05mm different

I don't have a 3-4inch mic so I had to use feeler gauges, not the best
method but I think it sufficed.

Im sending other stuff to RIMCO so I threw the cylinders in there too...
they are slightly scored from the lack of oil incident so Im going to have
them look them over, ridge ream them and maybe do a light honing depending
on what they find when the get in there with a bore gauge and check out of
round etc... things I don't have the tools to do.  Hopefully I can re-use
them with the pistons I have, they are not badly worn.

Thanks

Keith

Top Notch Restorations
topnotch at nycap.rr.com 
http://www.a383ina68.addr.com/radiorest/main.htm
71 Squareback "Hothe"
65 Notchback "El Baja Rojo"
65 Squareback "Eggcrate"
87 golf "Winterat"
93 RX7 "Redstur"

-----Original Message-----
From: type3-vwtype3.org-bounces at lists.vwtype3.org
[mailto:type3-vwtype3.org-bounces at lists.vwtype3.org] On Behalf Of Dave Hall
Sent: Friday, September 07, 2012 4:02 PM
To: type3 at vwtype3.org
Subject: Re: [T3] Mahle 1500 pistons

The SP section in my parts book doesn't admit what SP actually stands for.
The ST section is called Standard Parts.  All of the SP section have parts
numbers 3xx x98 xxx and a suffix letter sometimes. The third x is the group
- eg 1 for engine, 8 for body.  They all appear to be sets of parts that may
also be supplied separately - eg back-up light set or set of mouldings.

So if you see a box with 311 298 055 it's a tailpipe/damper pipe fitting kit
(ring gasket, clamp, nuts and bolt and the tailpipe clamp with mounting
screw) and 311 498 071 is a front wheel bearing set up to chassis 315 067
550.  The contents are usually found at the end of the relevant group
section.

I guess when you're likely to need all the bits, it's easier than ordering
them separately.

As far as Keith's pistons are concerned, I can't see any sure way to check
apart from measuring or offering them up to the barrels.  I'm not sure I
would trust a 30 year old label anyway!

Dave
UK VW Type 3&4 Club
===================

-----Original Message-----
From: type3-vwtype3.org-bounces at lists.vwtype3.org
[mailto:type3-vwtype3.org-bounces at lists.vwtype3.org] On Behalf Of Jim Adney
Sent: 07 September 2012 14:26
To: type3 at vwtype3.org
Subject: Re: [T3] Mahle 1500 pistons

On 6 Sep 2012 at 20:43, Keith Park wrote:

> Looking over the NOS Mahle flat tops im going to use in the crate, 
> they say
> SP0.05 mm on them in addition to the 82.95 number.
> They are part number 311 107 105 AA
> 
> There is no indication anywhere on them that they are oversize other 
> than maybe that SP number that is on the piston itself, the box is not 
> marked oversize anywhere, any idea what that SP number is??

It doesn't mean anything to me, other than the fact that I've seen lots of
VW parts boxes marked SP xxx, where xxx is some whole number. 
I've always assumed that it meant Service Part, or Service Pack, as they
usually held a collection of parts used together to perform some particular
job on a VW. Oddly, however, there is no mention of SP numbers in the
microfilm, the older printed parts books, or later dealer parts price books
that I have. My impression is that these sets of parts must have been an
older VW system.

This was just one more thing I always meant to ask Russ about, as there MUST
have been a reference to them somewhere. He must have been familiar with
them.

How does this number appear? Is it inked on the pistons, part of the box
label, or stamped into the piston crown?

If it's part of the box label, my best guess is that this is a Service Pack
specially put together to replace the dome top pistons with flat tops on
engines where the owners found the high compression to be a problem, as
perhaps in parts of the world where high quality gasoline was not available.

--
*******************************
Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
*******************************

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