[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

AAH vs AFC V6's



I was paging through the Bentley for my 100, and they actually list 3 V6
engines, the AAH, AAH/AFC and AFC. Here's the specs they list:

Engine Code                AAH                AAH/AFC                AFC
Dates                      11/91-8/94           8/94-5/95
5/95-
Liters                        2.771                  2.771
2.771
Output                      174 hp                174 hp
174 hp
Torque                      184 ft-lb               184 ft-lb
180 ft-lb
Bore                         82.5 mm              82.5 mm
82.5 mm
Stroke                      86.4 mm              86.4 mm                86.4
mm
Compression ratio     10.3:1                  10.3:1
10.0:1
Valve timing:
    Intake opens         4 deg.                10.5 deg.
10.5 deg.
    Intake closes        42 deg.               45.45 deg.
45.45 deg.
    Exhaust opens      42 deg.               37.5 deg.                 37.5
deg.
    Exhaust closes      2 deg.                2.55 deg.                2.55
deg.
Min. RON                  95                      95
91
Fuel injection            MFI                      MFI
MFI
OBD                        yes                        yes
yes
O2S control              yes                        yes
yes
Knock sensor con.    yes                        yes
yes
3-way cat. conv.        yes                        yes
yes
Exhaust gas recirc.   no                          no
yes

They also have a little explanation on why the oil circulation was revised
on engines produced 8/94 and newer. It says it was revised so that the oil
pressure refief valve in the oil pump is on the "clean oil" side. The
advantage is stated that the oil pressure is now controlled from the oil
filter and oil cooler, so that the oil pressure available at those locations
is supplied via the pressure relief valve or from the oil pump. No mention
on why the larger filter though. On the subject of OBD I and OBD II, it says
that beginning 3/94, manual transmission FWD vehicles with the 2.8 V6 have
OBD II capabilities. Surprisingly, there is no mention of when the automatic
and quattro V6's switched over to OBD II.

Craig
'92 100S (78k)