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 &amp998 as above but a hole in the front for temp gauge
12G185 (and/or marked as 12A185 * -see bottom of page- ) 1 1/16″
26.98mm
1″
25.4mm
24,6cc 997 Cooper fits as bigvalvehead for 850 &amp 998
12G202 1 5/32″
29,53mm
1″
25.4mm
26,1cc Austin/Morris 1100
and/or 997 Cooper * -see bottom of page-
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 itbecause 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″
26.9875 mm
1″
25.4mm
25.5cc 998 Mini
A+ and lead free
Last modified: 22 September 1996, with facts from Frans Marx
—–Enginetype—– ——Stroke—– —–Bore—– —–CC`s—–
1000cc 76,2mm 64.57

65.08

65.33

65.58

66.1

68

998

1013

1021

1029

1045

1106

1100cc 83,75mm 64,57

65,08

65,33

65,58

66,1

68

68,5

68,76

69,01

69,52

1098

1113

1122

1131

1149

1216

1234

1243

1252

1271

1300cc 81,28mm 70,61

71,12

71,37

71,62

72,12

73,5

73,65

74

74,15

74,40

1272

1290

1300

1309

1328

1379

1385

1398

1403

1412

1300cc Shortstroke 76mm 73,5

74

1289

1306

1300cc Longstroke 84mm 70,61

71,62

72,12

73,5

74

74,7

1316

1353

1372

1425

1444

1472

1300cc Longstroke 86mm 73,5

74

74,7

1459

1479

1506

1300cc Longstroke 91mm 73,5

74

74,4

74,7

1544

1565

1582

1594

850cc 68,25mm 62,94 848
Engine ———– Casting — Chamber volume —-
850

948

2A628

12A1456

2A629

24,5cc
997

1098

12G202 26,1cc
998

1098

1100

12G206

12G295

28,3cc
1275

1300

12G940

12A185

AFG163

21,4cc
Performance figures per type: According to ‘the sporting minis’ p. 119 Horse Power Max Speed (Mph) 0-60 time Mpg source
Mini Cooper 997 55 85 17.2 34.6 The Motor 20/9/1961
Mini Cooper 998 55 90 14.8 31.5 The Motor 6/11/1965
Mini Cooper S 1071 70 95 12.9 26.8 The Motor 24/4/1963
Mini Cooper S 970 65 92 n/a n/a
Mini Cooper S 1275 76 97 10.9 29.9 The Motor 5/9/1964
Mini 1275 GT 59 90 13.3 30.5 Autocar 6/9/1971
Cooper S Touring 1.3i 85 95 9.95 38.6
Cooper S Sport 85 97 9.65 36.5
Cooper conversion 998 64 88 13.2 29.6 Autocar & Motor 14/6/1989
Mini Mayfair 41 78 22 38.0 Autocar & Motor 23/8/1989
Mini “Hot Rod” 160
Mini Van 850 34 71 28.3 41.6 Mini Gold Portfolio ’59-’69 (p. 91-93)
Mini Clubman Wagon 1100 48 130 km/h 19.4 (0-100 km/h) 8.3 l/100km Mini Gold Portfolio ’69-’80

Date sent:       Tue, 28 Sep 1999 07:40:13 -0700 (PDT)
From:            Kelley Mascher <mascher@u.washington.edu>
To:              Theo van den Bogaard <T.A.J.M.vdnBogaard@uvt.nl>
Subject:         Re: BOUNCE Casting “MOWOG 12A185” on a cylinder head

Please feel free to use anything I write on
the list. Also please use any retraction I
may have to write later. ;^)

You have the most complete list I’ve seen for
heads and casting numbers. If you like I’ll
send you numbers for the North American
smog heads these were mostly from Canada.

I did notice a couple of anomalies in the list.
There is a typo, AEG163 is listed as AFG163.
Also there doesn’t seem to be a listing for
the 997 Cooper head. In my book it’s listed
as a 12G202.

Cheers and thanks for the website,

Kelley Mascher                                            (206) 528-2713
Children’s Hospital & Med. Center               mascher@u.washington.edu
Audiology Research                              Seattle, Washington USA

On Tue, 28 Sep 1999, Theo van den Bogaard wrote:

> Date: Tue, 28 Sep 1999 09:03:40 MET
> From: Theo van den Bogaard <T.A.J.M.vdnBogaard@uvt.nl>
> To: Kelley Mascher <mascher@u.washington.edu>
> Subject: Re: BOUNCE Casting “MOWOG 12A185” on a cylinder head
>
> Hi Kelly,
>
> thanks for the clarification, may I use this mail to quote from in my table ??
>
> TIA,
> Theo van den Bogaard
>
>
> Date sent:       Mon, 27 Sep 1999 09:10:17 -0700 (PDT)
> From:            Kelley Mascher <mascher@u.washington.edu>
> To:              Theo van den Bogaard <T.A.J.M.vdnBogaard@uvt.nl>
> Copies to:       mini-list@autox.team.net
> Subject:         Re: BOUNCE Casting “MOWOG 12A185” on a cylinder head
>
> >
> > Just before I wrote my last message on this
> > subject I went out to the garage. Sure enough,
> > the head said 12A185 in the casting and it has
> > the beak in the chamber like a small bore head.
> >
> > I recall measuring the valves when I first noticed
> > the casting number about a year ago. I though I
> > had myself a real Cooper ‘S’ head. Small valves,
> > the same as a 12G295. I wasn’t too disappointed
> > after all it was on an 850.
> >
> > Until someone on the list tells me that they have
> > a 12A185 head with AEG163 valves in it, I’ll assume
> > that the books are inaccurate on this point.
> >
> > Photos upon request…
> >
> > Kelley Mascher                                            (206) 528-2713
> > Children’s Hospital & Med. Center               mascher@u.washington.edu
> > Audiology Research                              Seattle, Washington USA
> >
> > On Mon, 27 Sep 1999, Theo van den Bogaard wrote:
> >
> > > Date: Mon, 27 Sep 1999 13:16:00 MET
> > > From: Theo van den Bogaard <T.A.J.M.vdnBogaard@uvt.nl>
> > > To: mini-list@autox.team.net
> > > Subject: Re: BOUNCE Casting “MOWOG 12A185” on a cylinder head
> > >
> > > Date sent:       Sun, 26 Sep 1999 15:39:30 -0700 (PDT)
> > > From:            Kelley Mascher <mascher@u.washington.edu>
> > > To:              krausefamily <krausefamily@uswest.net>
> > > Copies to:       mini-list@autox.team.net
> > > Subject:         Re: BOUNCE Casting “MOWOG 12A185” on a cylinder head
> > >
> > > >
> > > > I have seen the 12A185 head listed as a MkI
> > > > Cooper ‘S’ head.
> > > >
> > > > On the other hand I own a 12A185 head that
> > > > is a bog standard small bore head. It came
> > > > on a MkII 850 I bought for parts. I would
> > > > guess that it originating on an 1100 is
> > > > a definite possibility.
> > > >
> > > > Cheers,
> > > >
> > > > Kelley Mascher                                            (206) 528-2713
> > > > Children’s Hospital & Med. Center               mascher@u.washington.edu
> > > > Audiology Research                              Seattle, Washington USA
> > >
> > > http://cwis.uvt.nl/~dbi/users/theo/heads.htm
> > > lists the 12A185 as Cooper S
> > > and the  12G185 as small-bore
> > >
> > > .. perhaps the MOWOG got his lettes mixed up an a ‘bad’ day ??
> > > measure the valves and compare to the table …
> > >
> > > >
> > > > On Sat, 25 Sep 1999, list adMINIstrator wrote:
> > > >
> > > > > Date: Sat, 25 Sep 1999 22:05:44 -0600
> > > > > From: list adMINIstrator <chichm@planet.eon.net>
> > > > > To: mini-list@autox.team.net
> > > > > Subject: BOUNCE Casting “MOWOG 12A185” on a cylinder head
> > > > >
> > > > > BOUNCE   Non-member submission from [krausefamily <krausefamily@uswest.net>]
> > > > >
> > > > > Date: Wed, 15 Sep 1999 20:56:07 -0600
> > > > > From: krausefamily <krausefamily@uswest.net>
> > > > > Subject: Casting “MOWOG 12A185” on a cylinder head
> > > > >
> > > > > Does casting number “MOWOG 12A185” on a cylinder head give
> > > > > some indication as to the origins and application for the
> > > > > particular head?  One theory I’ve heard is that this is a
> > > > > head from an 1100cc Morris?  The other theory is that this
> > > > > is either a 1275cc head or will otherwise function with a
> > > > > 1275cc Sprite/Midget.  Can you shed any light on this?
> > > > >
> > > > > John Krause
> > > > > krausefamily@uswest.net
> > > > >
> > > > > *********************************************************
> > > > >      OK, so I’m busy getting on with my life, OK?
> > >
> > > HTH,
> > >
> > >
> > > Theo van den Bogaard
> > > Mini Cooper 1.3i BRG + ’71 Red Van
> > > 998cc Appreciation Society
> > > Mail: T.A.J.M.vdnBogaard@uvt.nl
> > >
> > >