|
| Model |
casting |
Inlet diameter |
Exhaust diameter |
Compression standard |
Bhp standard |
| 1300 America, 1275 Spridget,mini 1275 GT and standard Metro |
|
1 5/16"
33,33mm |
1 5/32"
29,53mm |
8.8:1 (GT) |
56 (GT) |
| 'S' units, MG metro, 1300 GT,'90's Cooper and Sprite Tbi |
|
1.4" (TBASE page 161 (2nd edition))
35.56 mm |
1 5/32"
29,53mm |
|
19-2-2002- from the yahoo.list: "Dear all
FB has probably seen this already,but it appears the Maestro/Montego 1275
models used the MG Metro big valve 12G940 cylinder head and cam to produce 69bhp.
According to Haynes they started off
with 1.312" inlets and 1.156" exhaust valves.But from engine No.12H999104761 and 804102434 they had 1.4" inlets.Which is worth
about 5bhp.Get down that scrapyard!
IAN Nicholls" |
| MG Metro Turbo |
|
1 5/16"
33,33mm |
1 5/32"
29,53mm sodium cooled |
9.4:1 |
94 |
| 1.3i minis with cats 1991 on |
|
|
|
9.4:1 |
|
| 1991on injection minis |
|
|
|
10:1 |
54
63 for Cooper |
| 1990-92 non injection coopers |
|
|
|
10:1 |
|
| 1000s with cats 1989 on |
|
|
|
9.6:1 |
|
| 1000s 83-89 |
|
|
|
10.6:1 |
|
| CooperS mkIII |
|
|
|
9.75:1 | Different heads to the A-series engine
compiled by Jerker Johansson,Sweden
1987 |
|
From the book: The Sporting Minis |
by: John Brigden |
ISBN: 0-947981-40-3 |
|
| Number of Casting |
Inlet |
Exhaust |
Volume |
Normally fitted to |
Fits also |
2A629
2A628
12A1456 |
1 1/16"
26.98mm |
1"
25.4mm |
24,6cc |
850 Mini, A35,A40,Minor, SpriteMkI |
998,1100 and Cooper |
| 12A1458 |
1 1/16"
26.98mm |
1"
25.4mm |
24,6cc |
late 850 &998 |
as above but a hole in the front for temp gauge |
| 12G185 (and/or marked as 12A185 * ) |
1 1/16"
26.98mm |
1"
25.4mm |
24,6cc |
997 Cooper |
fits as bigvalvehead for 850 & 998 |
| 12G202 |
1 5/32"
29,53mm |
1"
25.4mm |
26,1cc |
Austin/Morris 1100
and/or 997 Cooper * |
As above but square formed inlets |
| 12G206 |
1 7/32"
30.95mm |
1"
25.4mm |
28,3cc |
Early MG 1100 |
upgraded 12G202 |
| 12G295 |
1 7/32"
30.95mm |
1"
25.4mm |
28,3cc |
998 Cooper
MG 1100
Sprite MKIII |
Fits on 998 when bigger valves are needed |
12G940
9 Bolts |
1 5/16"
33,33mm |
1 5/32"
29,53mm |
21,4cc |
1275GT,A/M1300
Sprite MK IV
Marina 1,3 |
Can be modified to the specifications below |
12G940
11 Bolts |
1 13/32"
35,6mm |
1 5/32"
29,53mm |
21,4cc |
Austin 1300 GT
MG 1300 MK II
late Cooper S |
Fits on 1275 Gt when bigger valves are needed |
12A185
AEG165
AEG163 |
1 13/32"
35,6mm |
1 7/32"
30.95mm |
21,4cc |
Cooper S |
Can be used instead of the 11 bolted 12G940 |
| 12G940 |
1 5/16"
33,33mm |
1 5/32"
29,53mm |
21,4cc |
Turbo MG |
|
| 12G1316 |
1 5/16"
33,33mm |
1 5/32"
29,53mm |
21,4cc ?? |
1275 Austin America |
The 12G1316 is the Austin America smog head. It's a really beefy head and Vizard liked it because it had plenty of room
for modification. There isn't a lot of information on modding these heads, I suspect, because they were not generally available
in the UK. It's quite probable that Vizard knew of them through APT.
They are a good solid head, same valve size as
the standard (non-MG) 12G940. I think they are a good choice.
Cheers,
Kelley
|
| CAM4180 |
1.0625" |
1"
25.4mm |
25.5cc |
998 Mini A+ and lead free |
Last modified: 22 September 1996, with facts from Frans Marx |
|
