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Dutch924-racer · Joined: 23 Jul 2007 Posts: 1081 Location: The Netherlands

I can buy a set of pistons which came out of an Carrera GT.
The strange thing is that the pistons are from Mahle instead of Kolbensmith.

Is this possible or has the engine/ pistons already been swapped ealier?
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937 trackday car
Series 2 engine
951S turbo and intercooler
Fast road camshaft
Forge recirculation valve + boost controller

Fifty50Plus · Posted: Tue Jul 14, 2009 3:53 am Post subject:

Both companies have been piston suppliers to Porsche for many years. With some other early Porsches, each company sometimes made the same part.
Regards,
Chuck
Edit: In my experience, Mahle had done a lot of limited run productions for specific applications.
_________________
1979 924 NA race car H-Prod SCCA
1982 924 NA race car - Sold
1981 924 Turbo sold
1982 924 Turbo sold
1972 911 E race car - traded for Cayenne Diesel
1975 914 1.8 Building for H-Prod SCCA

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Per FSM, and as Chuck said, both were suppliers for 931.
_________________
Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

gegge · Joined: 27 Jul 2007 Posts: 1124 Location: Sweden

The GT pistons were forged and that is easy to see compared to the cast ones with marks from the moldings. The cast have reinfocements/inserts of steel on the inside of the skirts. The forged ones doesn't.
_________________
Carl Fredrik Torkildsen

924 turbo -81 Carrera GT RESTOMOD
924 turbo -80 Dolomite De Luxe
924 -85 DP kit, BBS RS, M030 and tuned engine
924s -86 Black on black turbo with Fuchs

gegge · Joined: 27 Jul 2007 Posts: 1124 Location: Sweden

This one is a forged GT piston from KS:

This is how a cast turbopiston from Mahle looks inside:

_________________
Carl Fredrik Torkildsen

924 turbo -81 Carrera GT RESTOMOD
924 turbo -80 Dolomite De Luxe
924 -85 DP kit, BBS RS, M030 and tuned engine
924s -86 Black on black turbo with Fuchs

cwr-fl · Joined: 15 Nov 2002 Posts: 50 Location: Lake Helen, FL

I have a damaged 937 piston on my desk that came from my 937 prior to the engine rebuild. It is a Mahle piston and the numbers inside are 86V53 and R011.
_________________
Chuck Russo
Lake Helen, FL

81 937 (924 Carrera GT)
88 924S M030 SCCA ITS
87 924S PCA I/SCCA ITS
87 924S (Redoing interior)
87 924S (Engine needs rebuilding)
85 944 (Parts car)

gegge · Joined: 27 Jul 2007 Posts: 1124 Location: Sweden

86V53 are common turbopistons. I got two sets of 86V53 and they are definitly cast.

V stands for: Auto-Hydrothermik or Auto-Hydrothermatik cast piston (piston w/ cast-in steel struts). Should be a P for forged or at least F for Pressure cast.

A Mahle guide:
http://www.motorenteile.mahle.com/eLIZA/mahle/pc/doc/pdf/en/piston_types.pdf
_________________
Carl Fredrik Torkildsen

924 turbo -81 Carrera GT RESTOMOD
924 turbo -80 Dolomite De Luxe
924 -85 DP kit, BBS RS, M030 and tuned engine
924s -86 Black on black turbo with Fuchs

Belgian924t · Joined: 07 Jan 2006 Posts: 104 Location: Belgium

jessy1984 · Joined: 09 Jun 2009 Posts: 82 Location: belgium

Belgian924t · Joined: 07 Jan 2006 Posts: 104 Location: Belgium

Hi, I live in Stekene. My garage is in Hulst, just across the dutch boarder.
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'79 931 with Carrera GT look
'86 944 turbo (sold)
'88 944 turbo S (sold)
'85 911 Carrera 3,2 (to be restored)
'80 911 SC "SOLD"
http://www.cardomain.com/ride/2224272