hi guys may have dropped on some reasonable 81mm wossner pistons , but problem is they made slightly smaller ,ie stock vr6 piston size is 80.985 wossner pisons size is 80.93? making these 0.07m smaller , plus on top of this theres bore wear , so surely isnt a good idea to fit them , unless it was a new block (hens teeth ) i know most would say get a rebore/rehone to a bigger size ie 82/83 mm whats ur veiws, as i phoned wosser up they stated all wossnerr pisons have a clearance of 0.07m due to expantion/temputures and state i wouldnt have any problems , im personly not conveinced. ive also read 4043 arnt that good in ways , found a link below http://speedtalk.com/forum/viewtopic.php?f=1&t=19612&start=15 (((oppss meant 4032 )))
Wossner are correct, forged pistons tend to run more wall clearance for expansion, so 80.93 will be fine. But if your bores are ovalised, it's a moot point anyway. FWIW, I have run 83mm Wossner turbo pistons for over 50K miles with no problems. I think the discussions taking place on that forum are perhaps a littel too indepth and out of scope for an average road car engine. My wossner block feels like it will do 100K no problems, which is good for a cast pistoned 12V, let alone a forged one!
