TBF in France ...no issue ?
10-14-2010, 01:55 PM
#31
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My genuine GTS pistons have 8 holes (1/2holes) around the skirt, just behind oil ring ...but I can't see where they go, don't seem to communicate to center....
10-14-2010, 05:26 PM
#32
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I'm sorry to listen that... Happily I could catch my S4 before she went downhill...
I can confirm what Constantine said, there are no blocks available from Factory - I know it first hand. The GTS blocks are different. Thought, they could be used.
However, I'd try to get a poper S4/GT engine and tune her - without major changes you can easily get about 438 HP and still have an engine that enjoys to rev. Or use a supercharger / compressor to improve it (I might get a LOTEC kit that I could offer you).
About the holes in the piston I'm quoting that note here from rennlist:
Good luck!
Marc
I can confirm what Constantine said, there are no blocks available from Factory - I know it first hand. The GTS blocks are different. Thought, they could be used.
However, I'd try to get a poper S4/GT engine and tune her - without major changes you can easily get about 438 HP and still have an engine that enjoys to rev. Or use a supercharger / compressor to improve it (I might get a LOTEC kit that I could offer you).
About the holes in the piston I'm quoting that note here from rennlist:
Good luck!
Marc
10-14-2010, 05:28 PM
#33
Former Sponsor
Note the build-up of oil on the sides and the top of the pistons. Since the oil could not return properly, it is trapped and gets into the combustion chambers.
Mahle simply forgot and Porsche didn't catch the problem.
Simple modification.
10-14-2010, 05:30 PM
#34
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10-15-2010, 12:55 PM
#36
Rennlist Member
Rarely the Gods of Rennlist fail, but today both Greg and Erkka were wrong...
https://rennlist.com/forums/928-foru...-pictures.html
Clearly you can see the 4 holes drilled by the factory and you can also clearly see that Porsche did not put any holes on the skirts like it did on the S4/GT pistons...
https://rennlist.com/forums/928-foru...-pictures.html
Clearly you can see the 4 holes drilled by the factory and you can also clearly see that Porsche did not put any holes on the skirts like it did on the S4/GT pistons...
10-15-2010, 01:07 PM
#37
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Just to make clear to people who don't know better. 
Alex has pistons which do not have anything to do with normal GTS pistons. Those are something special which haven't appeared in any other GTS engine.
Alex has pistons which do not have anything to do with normal GTS pistons. Those are something special which haven't appeared in any other GTS engine.
10-15-2010, 01:30 PM
#38
Rennlist Member
The pistons were found in my GTS engine, which was supplied by Porsche. So Porsche put them in and they are Porsche GTS pistons so to speak... 
I think Adrian Clark in the UK has seen similar pistons, but not made by KolbenschmidtSlightly off-topic - I took apart my GT motor and guess what I found - it is tolerance 1 block, but cylinders 1-4 were sleeved by the factory with alusil liners. WTF? Has anyone seen anything similar?
10-15-2010, 04:07 PM
#39
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01-09-2011, 03:40 PM
#40
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... some short news about my TBF !
..I've found a new block never used (I'm really lucky sometimes...) from a Porsche parts dealer (about 20 miles from my house !!!), and everything is Ok to start assembly !
I've cleaned all the pistons heads ( ...ouch ! couldn't see the 4 valves holes cause of carbon !!!), and drilled the 8 holes under the oil ring !
My 2 cylinder heads are checked with new guides, tomorrow my crankshaft will be balanced with everything necessary inclusing weight of one piston equiped... I hope everything will go on !!!
..I've found a new block never used (I'm really lucky sometimes...) from a Porsche parts dealer (about 20 miles from my house !!!), and everything is Ok to start assembly !
I've cleaned all the pistons heads ( ...ouch ! couldn't see the 4 valves holes cause of carbon !!!), and drilled the 8 holes under the oil ring !
My 2 cylinder heads are checked with new guides, tomorrow my crankshaft will be balanced with everything necessary inclusing weight of one piston equiped... I hope everything will go on !!!
01-09-2011, 06:54 PM
#43
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Really lucky if even tolerance group is correct between pistons and new block. Though group 1 seems to be more common in GTS engines than earlier models. Maybe Porsche got better with manufacturing tolerances.
