Firstly, let me apologise. I had no idea that a condition of posting on this board was that I had to pre-determine the age of all possible readers and ensure nothing is discussed that pre-dates the youngest whipper-snapper. The race has been running since 1923, for fucks sake.
Rev H - your epistle is as wrong as your spiritual diatribe. Being a committed and enthusiastic satanist, I am somewhat offended by your missionary position on this forum. Be gone, foul evangelist!
Steve - you are a quitter. For one as adept as you, at the snappy internet search, I am thoroughly disappointed.
For the rest of you (who obviously don't give a rats ass), the answer follows - and is quoted from the afformentioned authority, "Porsches at Le Mans", which is second only to Razzle in my library of on-bog reading matter.
"Twenty seven Porsches start - sixteen finish.
.....an interesting footnote is that, in fact 28 Porsches started: an Equadorian Carrera, #29, which had not qualified, somehow slipped into the starting line-up and had done three laps before the organisers spotted the car and stopped it!"