S1 exhaust manifold nuts ( what size are they ? )

[mytvrandbay]

Hi HELP!!What size spanner do i need for my S1 exhaust manifold bolts,trying to remove my down pipes and exhaust.Not whitworth not mm not AF ....!!!!! What are they ? are they UNC?
Cheers

[phillpot]

If same as later 2.9 engine they'll be M8 which is 13mm spanner normally. Should they be 5/16 UNC or UNF they'd be a half inch spanner size BUT may well be very corroded so "correct" spanner is too loose ?

A single hex or one of those sockets that drive on the flats not the corners may help but I know from experience on my S3 some of the heads are so close to the pipes can only get an open spanner on.

Guess worst case senario is cut/grind/chisel head off then unscrew remains with Mole grips once manifold is off ?

Good Luck !

[mytvrandbay]

Hi,thanks for replying so quickly.Something must be wrong with mine then.The nuts on mine are between 16mm and 17mm.(downpipe to manifold) 16 too small and 17 too big.Any ideas
Your help will be appreciated.
Thanks again

[phillpot]

5/8 AF ?

I was on about manifold to head bolts earlier.

[mytvrandbay]

Hi,looks like a cutting job then.They are siezed anyway.
Thanks again
P