GEN 2 BORE SCOR­ING

911 Porsche World - - Letters -

Well done 911&PW for con­sis­tently get­ting down and dirty with the hard facts and truths be­hind mod­ern Porsche own­er­ship and en­gi­neer­ing. I re­fer to Chris Hor­ton's on­go­ing in­ves­ti­ga­tion into bore scor­ing with 997 gen 2 en­gines, and no­tably the case study of a 2010 997 Turbo DFI en­gine, it cer­tainly makes for in­ter­est­ing read­ing even if there isn't a de­fin­i­tive an­swer or pat­tern and, as Chris says, ev­ery­one loves a 'who­dun­nit.'

Plac­ing the blame with the in­jec­tors does sound plau­si­ble, par­tic­u­larly in view of the harsh work­ing en­vi­ron­ment of a DFI en­gine. I have a vested in­ter­est be­cause I have a DFI 991 of 2012 vin­tage, which has so far been fault­less, but even so I will be get­ting the in­jec­tors’ resistance checked out, after the graphic image of the six in­jec­tors from the af­fected en­gine. After all it can't do any harm and it may of­fer a use­ful early warn­ing. Ob­vi­ously phys­i­cally check­ing the in­jec­tors on a DFI en­gine is pretty much im­pos­si­ble, with­out en­tirely removing the en­gine. Oh, for good old Bosch in­jec­tors on an ex­ter­nal fuel rail, that can be re­moved by a sim­ple twist and a tug!

Like many, my Porsche is a sec­ond car, so doesn't al­ways get the long jour­ney that it de­serves. One thing I al­ways do, though, is de­ac­ti­vate the stop/start. I don't care what any­one says, but this sop to emis­sions can't do an en­gine any good. Con­stantly squirt­ing a start-up quan­tity of fuel into the bore must pro­mote some sort of bore wash. Mod­ern so­lu­tions and un­in­tended con­se­quences spring to mind. James Prior, via email

Steve Ben­nett replies: We pride our­selves here at 911&PW in get­ting to the bot­tom of all man­ner of tech­ni­cal is­sues. Rest as­sured we will con­tinue to mon­i­tor the bore scor­ing is­sue and maybe one day ar­rive at a de­fin­i­tive an­swer.

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.