FOR THE

AND

948c.c. &l098e.e. ENGINES

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Issued by:THE BMC SPECIAL TUNING DEPARTMENT

ABINGDON-ON-THAMES, BERKSHIRE, ENGLAND

C-AKD 5097

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- ,..... -'.SPECIAL TUNING DATA

Issued by: The BRITISH MOTOR CORPORATION LTD.

SPECIAL TUNING DEPARTMENT. Ablnldon. Berkshire. Enllan<!

Hod.1 MITGET/SPRITE 948 & 1098cc She« So - 1 Issue 2

DESCRIPTIVE INDEX

Desc r i ptionBODYWORK

Bonne t s ecuring straps - Buckl e half- To ngue half

Retainer

P a r t No .

C- AHH 5518C-AHH 5519C- AHH 5517

Qty.. /Car

112

Shee t No.

B-6B-6B-6

B-3B-3

8-6

B-7B-78-7

8- 4B-2

B-4B-4B-4B-48-58-5

B-l ,B-2

B-3B-l ,B-3

8-1B-1

111

1

1111

11

112211

11

116

731229

816881696

1943304485

10785

3360

1154485449

135

44484449

C-27H 7766

C- AUDc- AJJC-AEAC- AHTC-AEHC- AJJ

C- AEA8SG

C- BTAC- BTAC- BTA

C- AHT

C- AHTC- AHAC-AHAC- ARA

C-SHAC-BHA

or

948 )29

0

( 2A

8RAJ<ESOS 11 brake pad set (Fo r disc brakes o nl y

CAMSHAFTCompet i t ion 24° , 64° ,Tuni ng 16°, 56° , 51° ,

CARBURETTERI f " Twin S..U.. Assembly

Installation Kit for C- AUD 194 Carbs .Fl a r e pi pe f or 1"''' S. U. -Carb . (St eel )

" II to " to " (Glassfibre)Weber 45 D. C. O.E. c a ibure t ter (M. G. B.)I ns t a llat i on Ki t & mani f o ld f or C-AHT 143

CRANKSHAFTHeav y duty, f or al l 948cc engine s (under consi deration)

CLUTCHHe avy Duty c lutch (Cove r as sy.From Engine No. Pref ix IOCC (Dr i ven plat e

DISTRIBl1l'ORFor us e with 2A 948 or C-AEA 731 camshaft

EXHAUST SYSTEMCompeti tion large bOre Mani f o ld3 Br anc h Manifo l d & clips AHA 5450PipeSi l ence r

FINAL DRIVE4. 55: 1 ratio , mat ched crown wheel & pinionLi mit ed s lip di f ferential

GASKS!'SCyl i nde r head jointManifold jointRocker covec joint

GEARBOXClo s e ratio f or AN5 only ( 2nd speed gear

(li s e wi th 22A 426, 22A 204(3rd speed gea rand 22A 207) (1st motion shaft

Straigh t cut c l ose rati o gear s e t compl et e

C-AEAC- AEAC- AEA.

C-22AC- 22AC- 22AC- AJ J

647411511

226227228

3319

1111

B-1B-1

8-1 ,8-3

B-18-1B-1B-8

cont i nued on Shee t Sa - 2,

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SPECIAL TUNING DATAIssued by: The BRITISH MOTOR CORPORAnON lTD.

SPEQAl TUNING DEPARTMENT, Abingdon, Berkshire, England

Model MIIXJET/SP RI TE 948 & l098cc Sheet Ba - 2 Issue 2

DESCRIPTIVE INDEX (Co n t ' d)

B-1

B-1

B-1B-1

B-3

B-1B-1

B-l ,B-3B-1B- 3B-6B-6B-3

B-1

B-6B-6B-6B-68-68-6B-6B-6

s-r. e-sB-6B-1B-1

Sh eet No .

4

5

88888131

84

11211111

1111

1

Qty. / Ca rPart No .

C- 2A 94 6

C- AKD 10 21C- AKD 5061C-AKD 5093C-AKD 5097C- AKD 5100

c- 2A 954C- 2A 9 5 5

C- AHA 7906C- AHA 7907C- AHA 82 72C-AJJ 3322C-AJJ 3314C- AHT 56C- AHT 57C- AJJ 3356

C- AHA 7 573

C- AJJ 3324

c- 2A 950C- AEA 432C-AEA 494C- AEA 49 3C-AEA 524c- xas 399c-xzo 392C- AJJ 3325

C-AHA 6451C- AHA 6452C- AHA 6453C- AHA 6454

R. H.L.H.R. H.L. H.

FrontFr on tRea rRear

Shock absorber , ad j us t able(For t e l l i ptic s pr i ngs onl ya f t e r Car No . HAN 5/ 4333)

Shock abs orbe r , ad jus t abl e Rear R. H.(for '" elliptic springs only ). Rear L.H.

Lowe red Rea r Road Spri ngs (t elliptic)Front s uspen si on l owe r ing kitAnti- r oll bar kit compl ete 9/16" di.a,Anti- r oll bar i" d i .a,An t i - roll bar 1l/16u dia.Ins t a l la t ion Kit f or C- AHT 56 & 57

VALV E GEARVal ve s pring - Outer (9C e ngi nes onl y)

Bottom col l ac . f or spr i ng AEA 40 1Valve sp ring - Inner, f o r 9CG & lace enginesBot tom col l a r f e r C-AEA 494 spr i ngsValve s pri ng - Oute r , f or l OCe engi nesStrengthened rocker s haftDi 5 t ence tubeDuple y. ti~ing chain ki t

WHEELSWire , 60 spoke 13" x 5"

De sc r ipti onLI TERATU RE

Speci al Tuni ng Bookle t - Spr i t e Mk . I on l yBi nder - f o r Tuning She e t sDi vi de r se t for Bi nderTuning Booklet (948 & l 0 98cc Engi ne s )B. M.C . Speci a l Tuning Rose ttes (1 pair)

PI STONHi gh compre s s i on fl a t top Std .

(a l so +. 010 " , +.020", +. 030" & +.040" )(Fo r 9C and 90G engi ne s on l y)

Pis t on r i ng - c ompre ssi on, al l sizesPi s t on r ing - scra pe r 1 al l s i zes

SUMPDe ep s ump and oi l pick-up kit

SUSPENSIONShock ab sor ber , compe t ition s e tting

, IM'~TANT: Tvn'", oi ell. IeIM ct.i:iib-dcinchb.hMt lI_prealy adllMd -br che c.ma q/ tIMWarnncrcltM~.~.

I

SPECIAL T0NING DATA1sS1i.-'I'~y: The BRITISH MOTOR CORPORATION LTD,

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'SPEClAL TUNING DEPARTMENT, Abingdon, Berkshire, England

Model SPRfTE HfAN 5 , HfAN6 & MIrx;ET GfANl $hee( 8 - 1 Iss.. 5Engine Type Prefixe s 9C & 9CG

,<N. B. ¥~$~ of t he engi ne par t s can be fit ted to any B . M.C ~ 948cc engine i f -carei s t~en in t he sel ection of parts i n conjunc t i on wit h t he .Mechanical Parts List.

946

793229

7766511401432950402434493653

544854491354 11

c- 2A

C- l\II!\C- l\II!\C-!IRAC- AEA

12GSSG

C- 27HC- AEII

AEAC- AEAC- 2A

AEIIC- AEAC- AEA.

AEII

Detai led t uning information f or 9C engines is described in Tuni ng Bookl etC- AKD: 1021 mos t of which a lso appl i es to 9CG engines . The f ollowing parts ares t i l l avai l abl e , but before car r yi ng out any tup~ng of t hi s nature . ens ur e t ha tthe engine i s i~ good condition .

High compre s s i on piston (9 . 3:1 )( St d . , + _0 10", +. 0 20" , +-030" & +· 040" sizes)

Oi l pump- l a rge c apa cityCamshaft tUning (2A 948)Distributor. f or tuning camshaftRocke r cover j o i n t - F.J . typeValve spring - inner 9C ONLYBottom collar for inner spring 9C ONLYVal ve s pr i ng - "outer 9C ONLYTop cup , f or doubl e springs 9C ONLYValve s pring, i nner 9CG ONLYBottom Collar f or spring 9CG ONLYTo p cup f or springs 903 ONLY

Competit i on exhaust sys'tem, 'compris i ng :Manifol d <i.nc l udes c lip s AHA 5450 )PipeSi l encerJoi nt - manifold

Use the fol l owi ng pa~ts t o conver t 9C gearbox to 90G clos e r a t i os .

Std. CfR1st 3.63 3·20 1st speed wheel2nd 2· 37 1. 92 2nd speed gear (28 tee t h )3rd 1.41 1· 36 3rd speed gear (24 teeth )

Rever se gear1st motion shaft ( 20 t eeth )Laygea r (26 , 2 3 ,19 & 1 3 t eeth)

Compet ition shock aosorbe r

Ad j us table' s hock absorber(Af t e r Car No. H/ AN 5/ 4333 onl y)

Strengthened disc road wheel8. M. C. Speci a l Tuning Ros e t t es t i pair)J oi nt - cyl i nde r head

R.H. FrontL. H. FrontR.H. RearL. H. Rear

22A 426C-22A 226C-22A 227

22A 204C- 22A 228

22A 207

C- AHA 6451C-AHA 6452C-AHA 64 53C-AHA 6454

AHA 6455C- AKD 5100C-AE:A 64 7

N. B. No t uni ng was ever r ecommended for the l OCG Engine .

-".~, .~----

------:•• lfCHlTANT: T ,cf tMkl_.~Md...,_ ", ,, .',Warn;u t) oi,• ..•1Ihich --- . --.

SPECIAL TUNING DATAIssued by: The BRITISH MOTOR CORPORATION LTD.

SPEOAL TUNING DEPARTMENT, Abingdon, Berkshire. England

Issue 4Sheet B - 2Maciel SPRITE H/AN8 & MIDGET G/ AN3( ~gine Pref i x IOCe only)

Bef ore carrying out any t uning on t he s e ca r s , i t i s essential t o ensur e thatbo th t he engine and chas s is components are i n good mechanical c ond1 tion. Wo rkshopManual AKD 4021 is avai labl e givi ng f ull details of t he correct maintenance andr epair or t he car. Parts Lists may also be obtained quo t ing the f ollowing Par tNumber .

Aus tin Hea l ey Spri te Mk.I & Mlc. I I Mechanic a l Pa r t s Li s t AKD 3566& M. G. Midg e t Mk . I Body Parts Lis t AKD 3567

Austin Heal ey Sprite Mk. I I I & Mk.lv Body Par ts Li s t Al<D 3514M.G . Midg e t Mk . I I & Mk. I I I Mechanical Pa r t s Lis t A!<D 3513

Cylind e r Hea dA s mall i ncrea s e in power c an be obtained by l i gh tly polishing t he va l ve

ports and cowbustion c harrber s . However, do no t al ter t he shape of these as t heya r e cas t to optium s hape. In addit i on , t he compr es s i on ratio can be raised bymachinin g t he f ace of t he cylinde r head in accordance with the f ollowing tabl e ,which shows the power out put f i gures assuming polished va l ve por t ,s ,

Ignit i on Setting B~T . D .C. & S .H.P . @ 6OCJO RP MComp . Machine CombustionRatio Head Chamber c c Std. Camshaft Camshaft 2A 948

8· 9 ,1 NIL 29 c c 5° 60 BHP 2° , 6 3 BHP,t· ~ : l . 0 35" 26· 5 cc 3° 62 BHP 1° , G5 BHP,

10 : 1 . 060" 24 . 7 c c 3° 62· 5 8HP 0° 6 7 BHP, ,10·5 ,1 .080 " 23.2 c c 2° 64. 5 8HP 0° 68. 6 BHP• ,

oopens 51 BBDC. c l os esTappet c learance · 0 15"

CamshaftA camshaf t wi t h i ncreased opening pe r i ods Part No . SSG 229 ( 2A 948)

be fitted . This c amshaf t will give the powe r outputs sh own i n t he chartt he f o llowing specifica t ion .

Inlet opens 16° BTDC. c los es 56° ABDC. Exhaus tVal ve lif t 0 ·312"

mayand

a] sohas

Distribut orUse a new Di s tri but or Part No. C- 27H 7766 with this camshaft, but t he s t andard

ai r c l eaner s and ca r buret t e r needles are r e t ained. Alte rnat i vely pancake airc l eaners 12A 222 may be f1.tted usi ng screws ZCS 0 51 3 (2 of f) and ZCS 0 51 2 (2 o f f ) .GZ needles ( Part No. AUD 1473) should then be used ( r i c h AH2, Part No . AUD 1059 ,weak EB, Part No. AUD 1149 ) with red piston s pr ings Part No . AUC 4387.

Exhaus tAn extr ac tor e xhaust manifo l d C-AHA 5448 i s also avai l abl e which wil l

i ncrease t he power output by a f ur t he r 2- 3 B4H.P . when used with either t hes tanda rd camshaft or SSG 229. The standar d exhaus t sys t em will be qui t esa t i s f ac t or y for use wi t h this mani fo l d and s t age of t une .

IMPOIlTANT; Tl,lnlfll oI t.... klnd dlscribed on thluhelt .. UPi '7 ud'Hd b7 the terms at theW,,""lJ' 01 the "ehlde rnanufKwrer.

It

SPECIAL TUNING DATAIssued by: The BRITISH MOTOR CORPORATION LTD.

SPECIAL TUNING DEPARTMENT, Abingdon, Berkshire, England

Issue 6Sheet B-3MOdel SPRITE H/AN8 & MIDGET G/AN3(Engine Prefix loce only}

Valve Spring~

Stronger valve springs are available, but do not use springs any strongerthan'necessary, as the load on the valve gear is increased.

The following spring should be used in sets:

140 Ibs. Valve Springs Inner AEA 768 8 offOUter AEA 767 8 off

165 Ibs. Valve Springs Inner C-AEA 494 8 offOuter C-AEA 524 8 off

Use with - Bottom cup AEA 403 8 off

A heavy duty rocker cover joint C-AEA 511 is also available ..

Valve Rocker

Forged valve rocker AEG 425 are available, which can be ground at the sideto lighten them. Note that only screw AEG 167 or lengthened screw C-AEA 692will fit these, together with locknut FNN 60S as the diameter and thread aredifferent.

Timing Chain

When using competition camshaft and stronger valve springs, the standardchain will wear and stretch very quickly. A duplex chain can be fitted, usingthe correct camshaft and crankshaft sprocket.s , The front plate will needcountersinking to take special bolts, but all the necessary parts and instructionsare contained in Duplex Chain Kit C-AJJ 3325.

Deep Sump

In order to prevent surge away from the oil pick-up when cornering, orbraking violently in driving tests, etc. a deeper sump is now available. Thisrequires the oil pick-up to be lowered to the bottom of the sump, and all thenecessary parts are contained in Deep Sump Kit C-AJJ 3324.

Clutch

A competition clutch cover assembly C-BHA 4448 is available with strongersprings to prevent slip. This should be used with a competition _driven plateC-BHA 4449 designed to withstand a certain amount of slip. If a very highdegree of tuning is being undertaken and the car used purely for racing, itmay be necessary to obtain a special clutch assembly to suit these requirements.

Exhaust Manifold

A large bore competition exhaust manifold C-AHT 11 is available fori1bsolut0 maximum power, when the cylinder head ports have been opened outfUlly and twin It" carburetters are fitted. An exhaust system can be speciallymade up to suit this manifold with a suitable size of silencer.

IMPOaTANT: Tunlnt 01the kind daetlbed Oft this sheet Is exp. eal, exduded by the termsd theWUTVlty olth. ",--"kl.mlllufatturer.

UI'HOGIlAPHEO IN ENGLAND

SPECIAL TUNING DATAIssued by: The BRITISH MOTOR CORPORATION LTD.

SPECIAL TUNING DEPARTMENT, Abingdon, Berkshire, England

Issue 4Sheet B - 4Model SPRITE H/AN8 & MlffiET G/AN3(Engine Prefix lace only)

Large S.D. Carburetters

1+" s s u, carburetters are available as a pair C-AUD 194 together withInstallation Kit C-AJJ 3304. Remove the standard carburetters, but beforeremoving the heat shield, use one of the insulators Part No. AHH 5713provided in the Installation Kit C-AJJ 3304 to mark out the larger diameterinduction holes in the heat shield and file out to suit. Holes should bedrilled in the lower edge of the heat shield immediately under the throttlereturn spring levers to anchor the springs. Two insulators for eachcarburetter must be fitted over the heat shield to maintain induction pipelength. The bore of the manifold is already chamfered to accept largercarburetters but can, with advantage, be cleaned and polished.

The existing connections for the throttle and mixture cables are used,but the mixture cable is clamped to the abutment bracket which, in turn, isbolted to the inside of the carburetter air cleaner flanges. No air cleanersnre called for but trumpets C-AEA 485 (steel) or C-AHT 10 (Glassfibre) areavailable to suit these carburetters.

The carburetters supplied C-AUD 194 are fitted with No.6 needles, butsome engines may be better suited by No. 5 needles which are slightly weakerthroughout the range. Rich Needle No.7.

Using these carburetters with polished valve ports, camshaft 2A 948,distributor C-27H 7766 and extractor exhaust system C-AHA 5448, the poweroutput will be as shown in the following table according to the compressionratio.

Alternatively, camshaft Part No. C-AEA 731 may be fitted, which will givethe power outputs shown in the table and has the following specification.

a a 0 0Inlet opens 24 BTDC, closes 64 ABDC. Exhaust opens 59 BBDe, closes 29 ATDCValve lift 0·320" Tappet clearance 0.015"

With this camshaft, the same needles and distributor will be required, butsee the table for ignition timing.

Camp. Machine CombustionIgnition Setting B.T.D.C. & B.H.P. ® 6000 RPM

Ratio Head Chamber cc Camshaft 2A 948 (8SG 229) Camshaft C-AEA 731

8· '): 1 NIL 29 cc 5° 68 BHP ,0 69 BHP0'

~ ,9·5:1 .035" 26·5 cc 5 , 70 BHP 4° 71 BHP

10.0: 1 ·060" 24.7 4° 720'

73 BHFcc BHP 3 ,1O~ 5:1 .080" 23· 2

0'73·5 BHP 3° , 74 BHPcc 3 ,

IMPORTANT: Tunln, of 'he kind dac:rl_d on~&sh_1$exp....ty excluded by the ter'm$ of dieWvnnty elf the vehlcltl manuflctvrer.

LlTHOGIW'HEP IN ENGLAND

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••••SPECIAL TUN1I'JG 0/\TA

Issued by: The BRITISH MOTOR COPJ'ORATlON LTD.

SPECIAL TUNING DEPARTMENT. Abingdon. Berkshire, England

"f '~ ·- '., ' f ;'-" :·:

Modlll SPRITE H/AN8 & mOOET G/AN3 laue 4

RoCker Shaft

A s trengthened r ocker sh aft ( A) Part No. C- Affi 399 is now a v::ailable, wh i c hr equires an additional tapp~d pedestal ' (8 ) 12A 210 , locking plate (C) 2A 515 andlocating screw ( D) 2A 258. The loc ating screw ( El i n the r ear pedestal shoukdbe cut of f flush with t he end of t he t hread , s o that the oi l f eed t o this pedes t a li s still maintained . The location is now maintained by the adj acen t pedestal ( B)which should line up with the repositioned hole i n the new rocke r shaft .

Alternative ly , one of t he existing pede s t a l s may b e drilled to s upply theo il f eed f rom the h ead t o the s h af t , bUt ensure i t i s f itted in the c orrectposition.

F

\4 • • .- • • • • • III

To reduce friction, t he coil spring r ocke r spacers can be replaced by s ol i ddi s t ance t ubes ( F ) Part No. C- Affi 392 ( 3 off) and spacing washers (G) Am 168( 6 o ff ) . These shoul d normally be eithe r s i de of the end pedes tals, but may bemoved t o ensure each ~er i s immediately above the valve s tem.

Fan Belt

Where reg-ulations permit running without a dynamo, use the s t andard waterpump pulley 2A 601 and s ho rt fan belt Pa r t No . C- AEA 539. A spare fan belt oft he correct type can be clipped around t he timing c as e and water pump f or aquick changeover i f one breaks dur i ng compe t i t ion .

Weber Carburetter Mani f ol d

For abso lu t e maximum power . a spec i al mani fo l d is now avai l abl e t o take~ 45 D. C. O.E. Weber car bur ett er . Kit C- AJJ 3360 i ncludes t his manifold and allthe contro l rods, l evers , s prings , fuel pipes , et c . neces sary for mounting t hecarburetter.

In view of the wide variat ions in tuni ng , it is no t poss i ble to advi s e onsui t abl e jet s , but Weber carburet ter C- AEH 785 has 36 %chokes and wil l onl y r.eedchanges of jets.

IM"",IANTI TU~lnf t1It.he tlfMf dllcrtMd ontl.- JMiet... .... 't ud;:sd:..:;:.,.;":....~..:::,:..~"':;:...:::"--------­W ••MtjJ of t'" ""Ie» 1MfMIfw:cutw.

~HID IN ENGLAHO

" ,."....• ',.'. ....-. ''''.''"/',.\ ..,..'. . --• BMC".' . -;'..-~ "-:.:.. ;/'~-..... co.,~..~. ';. .

SPECIAL TUNING DATAIssued by: The BRITISH MOTOR CORPORATION LTD.

SPECIAl TUNING DEPARTMENT. Abingdon. Berkshire. England

Model SPRITE & MIDGET Sheet B - 6 Issue 3

~etition Shockabsorbers

Front shockabsorbers with a harder setting are available Part No.C-APA 6451 Right Hand, and C-AHA 6452 Left Hand. Before fitting these,they should. be held in a vice and the lever operated for the full lengthof its stroke for a few minutes to expel all air from the valve ..

Rear adjustable shockabsorbers are available Part No. C-AHA 7906R.H. and C-AHA 7907 L~H. These can be adjusted in position to suit theride conditions required.

Anti Roll Bars

A 9/16" (14.3 %J di.a, anti roll bar is available as an optional extraon new cars, but this bar can also be fitted afterwards using kit C-AJJ 3314which contains all necessary parts and fitting instructions..

For competition two larger diameter roll bars are available, ttl (15·9 %)dia. C-AHT 56 or 11/16" {17.5 %J dia .. C-AHT 57. These will fit straight ontocars already fitted with a works roll bar, but if no roll bar has previouslybeen use~ installation kit C-AJJ 3356 is required.

~ension Lowering

The front suspension can be lowered about 1" (25 %) with lowering kitC-AJJ 3322.. It is important to fit the rebound stop packing which isincluded in the kit.

Reference to the Mechanical Parts List AKD 3513 will show that twodifferent front road springs have been fitted in production. Part No.2A 4214 was fitted to earlier cars, but when 'AHA 8003 was fitted, thi&raised the car, which may be useful on earlier cars being used for rallywork. Obviously it is essential to use two of the same springs.

Rear road springs, with a lowered setting for racing are availoblePart No. C-AHA 8272 {2 off} and should be used in conjunction with the frontlowering kit C-AJJ 3322.

Bratees

The standard rear brake lining will be set.Lsfectory for most competitionuse, but competition DSII pad sets are available to eliminate fade under severeconditions Part No. C-AHT 16.

Bor:net stra~

Leather bonnet straps are available to provide additional safety with theforward oper.ing bonnet on these cars. Use:-

Bonnet strap buckle halftongue half

- retainer

C-AHH 5518C-AHH 5519C-AHH 5517

1 off1 off2 off

IMPORTANT: Tunln.4_klncI~Oft thk.... II ....' tr exduited...,. eM __at.Wa,.,alltJd... YlIhIdtl matlufKturw.

SPECIAL TUNING DATAIssued by: The BI\ITISH MOTOI\ CORPOAATION LTD.

SPECIAL TUN ING DEPAI\TM ENT. Abingdo n. Berksh ire, England

.-Hodol SPRITE AND MI I::GET Shoot B - 7 Issue 2

.__-c____-7A

Axl e Ratios - Ea r l y CarsTwo t ypes of r e a r a xle have been £ i tted to t he s e cars, and not a ll e re....m

wheel s and pinions are i nterchangeable on the e a rli e r type. The f ol l owingt able shows the relative part numbe£s of t he main component s. £or us e on Mk .I~nd Mk. II Austin-Healey Sprite UP TO CAR NO. H-~7-247 31 and M. G. MidgetUP TO CAR NO. G-AN2-16183 ONLY. The s e may b e identif ied by the o i l fille r p l ugbeing in t he carrier assembly ' B' J and not in t he axle case. For part numbersof sp~cers and bearings, the appropria t e vehic l e Mechanical Part s Lis t shou l ~

be consulted .

Par t s mar ked • are no l onger ava~lable , but are ~nc luded f or r efe r ence •

Axle Ra t ios - Lat e CarsAFTER Spr i t e Car No. H-AN 7- 24732 and Midge t Ca r No . G- AN 2- 16194 , a new axle

as s emb l y was fitted , whic h may be identified by the oi l fil l e r pl ug i n t he axlecas e . This was fit t ed .....ith 9/38 Crown wheel and pinion BTA 539 , Ca r rie r Assembl yBTA 549 , and t he Di f f erent ial Assembl y Part Number i s BTA 550.

Only t he followir~ alterna t i ve r a tios wil l fit t hi s di fferentia l as s embl y:

3.727 , 11/41 t eeth Crowr. wheel and pinion BTA 5354.555, 9/41 t eeth Crown wh~el and ~inion C- BTA 816

N.B. ALL axl es mentioned are fitted wi th Diff e r enti al Cage ATA 7036 (I l l us . C) ,and can ALL be fi t t ed with Limit ed Sl i p Differential s C-BTA 696 and C-BTA 881(a l t e rnatives ) .

StrongPr Axl e ShaftsFor competition use, it is possi b le to fi t the 1 ~ 7 5 axle shafts BTA 806

{Di sc Wheels > or BTA 807 (Wi r e I,o,'heels ) .

c.w. & P. Carrier As s y.No .of Part No. Pa r t No . Diff e cential

Ratio Teeth Il l us t r ation A I l lus t r a t i on B Ass • Part No . St anda r d Mode l

3· 727 11/41 ATA 7240 • ATA 7167 ATA 7239 • Early Riley 1·53· 900 10/ 39 C-ATA 7354 • ATA 7167 ATA 7353 • -4· 222 9/ 38 ATA 7266 ATA 703 2 ATA 7326 Early Spr idge t4·555 9/ 41 8G 7129 ATA 7032 ATA 7093 Mor~is t Ton V~n

4·875 8/39 C4 110 ATA 7032 2A 7230 A35 Van5· 375 B/43 ATA 7040 ATA 70 32 ATA 7073 Merds GPO Van

• •

IMrotITANT; T. "'''I cl thekltaddelalbed 011 this I I'lftt "aiM 'YadYo.d by elM: tennI cI dwW.......,. 01 die~~fa:cw• .

,,-- .. -

SPECIAL TUNING DATAIssued by: The BRmSH MOTOR CORPORATION lTD.

SPECIAL TUNING DEPARTMENT, Abingdon, Berkshire, England

Modo! SPRITE AND KIDGET Sheet B - B Issue 1

Clos e Rat io Gea r s (He l i ca l Cut) NO LONGER AVAILABLE

De t ai l s are i nc l uded for r e f e r enc e purpcs e s , but replacements a re nolonger availabl e from the Factory. The f ollowing parts cou l d b e fitted togear boxes havi ng ' A' series teeth (See ,Mechanica l Parts List f or details )t o convert t hem to c lose ratic :-

C- 2 2G 304C-22G 305

1st Motion Shaft ( 21 t ee t h )Laygea r (25, 23, 19 & 1 3 teet h )

Close Ratio Gears (St r aigh t Cut)

For competition use where some gear noi s e is accept able , close r a t iostraight cut g ears are available g i vi ng the following ratios: -

C/R (s t d . )1st 2· 573 ( 3.2)2nd 1· 722 (1 .92)Sr d 1· 255 (1 .36)

" Af ter Engine No. l OCC/Da/H4642 and l OOClDa !L2356 close r ati o gear kit': C-Jq.g 3319 will b e requi red. This cont ains t he ge a r s and all the neces sary

l,o.~shers and join t s r equired. On a ll 9CG engines and IOCC engines BEFORE"'the abov e changepoint, use the following parts.

Clos e r a tio gear- kit C-AJJ 33191st Speed Whee l 22G 326Reverse Wheel 22G 240

'N. B.. An improved Lay s haf t 226 613 is now f i tted in produc t i on and s hou ld be<u s ed with these c lose ratio gears•

.These gears wil l NOT fit ge arboxes from e ngines wit h a prefix 9<:./ .

1st2nd3rt!. i.-

N. B. I t these ge ars requireas detailed below.

Thes e parts gave the fo llowing ratios :

C/R ( St d.)2.93 ( 3·20 )1· 754 ( 1 · 92 )1 ·242 (1 .36 )t - 0 I ' 0

replacernerit -;-"s fraight cu-r-geat" ~t rr.ay be u sed

,,

.j,

tMPORTA,NT; Tun"'. of elM kind cMtcriW on thb aheiIt is _rw-Iy ududed by the urn 0( en.W~,of,tk yehlch rlllIMlhav.rw.

UNOGu.fllO 14 8 .... 'IIID

m _

, ' ' , ,,,,IIlIll_.' ,,." ...,. . ._. .­,- "/"",-'.....It ., •.a_:; BMC :-'. _,j•.~".._..,' .~,.... ;.,

'...... ;S, , /"

SPECIAL TUNING DATAIssued by: The BRITISH MOTOR CORPORATION LTD.

SPECIAL TUNING DEPARTMENT, Abingdon, Berkshire, England

Model GENERAL Sheet z - 1 Issue 3

The fdllowing information is issued in order to facilitate the choice ofQ sUitable final drive ratio for any particular application.

Toe table indicates the wheel revaluations per mile for the tyre sizeCO~dhly used on B.M.C. vehicles. From this the vehicle speed per 1000 enginereVolutions per minute can be calculated using the formula.

60000

axle ratio x wheel revs per mile

or K.P.H./lOOO R.P.M. 96560

axler~tio x wheel revs per mile

This formula gives the speed in direct top gear only but the equivalentroad speed in any intermediate gear can be calculated by dividing this by thegearbox gear ratio.

Tyre Size & Type Wheel revs Tyre Size & Type Wheel revs(Dunlop) per mile @l 30 MPH (Dunlop) per mile @ 30 MPH

520 x 10 C41 1058 145 x 13 SP 934145 x 10 SP 1095 165 x 13 SP 892520 x 10 CW44 1060 175 x 13 SP 874500 x LlO R7 1053 •

520 x 14 C41 865550 x 12 C41 960 550 x L14 R7 807 •-145 x 12 SP 980 560 x 14 C41 853155 x 12 SP 960 590 x 14 RS5 842550 x 12 CW44 955 590 x 14 C41 831

145 x 14 SP 8925;20 x 13 RS5 914 155 x 14 SP 873520 x 13 C41 917 165 x 14 SP 854560 x 13 C41 884550 xL13 R7 840 • 550 x LIS R7 775 •590 x 13 RS5 871 560 x 15 C41 814590 x 13 -B6'I<41 867 590 x 15 RS5 807600 x L13 R7 807 • 590 x 15 C41 803

500 x LIS R7 747 •165 x 15 SP 820

.• Wheel revs @ 100 M.P.H.

For further information contact the tyre manufacturers direct.

I~~~:r~..!:!unln&~~~"kindd-.crlbedon this sheet b expnssly excluded by the terms 01 cbelJ'(~ty\:~~~IJ~enlcle''''~nufliCtu ....

SPECIAL TUNING DATAIssued by: The BRITISH MOTOR CORPORATION LTD.

SPECIAL TUNING DEPARTMENT, Abingdon, Berkshire. England

-Model GENERAL Sheet z - 2 Issue 6

The f o llowing c h a rt s r.o....rs details of the va r-ao u a B. M. C. camshaf r.s pro duc e df o r 'A' se ries in- l i ne and Lra~sverse e ngi nes .

Part Nos with 80 712 1'" 165 Am 148 8 80 - 2Q AEG 51C C- }\ EA 731 C-AEA 643..~ , -\ ,pin type o i l 2A 297 AEA 6 30 2A 948

pump d rive . '2/< 571 1ZA ' MII .. U

Harking 2 r i ngs 1 =i.ng 1 r~ng - r-ings AE}, &4S- - I,

cam lobe wJ.dth i" t " t " ' " ' " i " -~. ".. ~ ,

Standa r d use Mini 1100 & Cooper' S ' Cooper Cooper ' S ' Ra c i r.g IMidget Mi.aget II 997cc 1966 •

X 5° X 5° " 5° X 16°@ lr? tI' 24°

@ -I nlet: opens ETDC 5Co

Icl oses ABDC 45° . • 0 • • 0 56° . SOO 64c xP-, ~ o.;, 'J' "Exh eu s 't opensBBDC 40° , , 0 5:i

0 51° 51° c , o 75°0 , -, ,:!

c10sesATDC 10° ~. ~ 0 21° 21° 21° ""ao 4 'c ,a c _ ,

, I

2?J.:P 23rF 2?IJo,

2c"P 240° "' _00 300° IiI n l €' t peri od -.. ,-,. b L'

Exhaust perio d 2 30° 2520 2 r.: ~o 2520 252

025S

o 300°J <

Cam lift · 221 " · 250" .... SO" • 2 50" • 250" · 25 2" · 31 5"• <

Valve lift • 28 5" • 31S" • 31 Q " . 313" • 318 " • 320 " • ~Q4".- " "

Runni ng Clear ance . 0 12" · 012" · 0 1 2" . 0 15" • 0 1 5" · 0 1 '.)" . 0 15" ,(030 %) ( · 30 %) ( . 30 %) ( .38 %l ( . 38 %l ( 038 %> ( . 38 "i )••

Par t Nos wi th I 12AI 0 6 5 12G 72:6 Affi 522 C- AD:iS6 7 C- AEES4 2 - C- Affi S29•

Q ,...E~s pid e r pump drive • • <: ? "jo u > -

Ca.", l obe width J" -t" t n +" *" i ",Mar k i ng s - - - Affi567 AEG54 3 AEG 530

- ? ring l; - - 1 Ll.ng -•

Fe ::' Ldentdf Lcatuon s ee ma r kings arn ::1 c am l obe \·;id t h (i" ,

" Fo r- checking , se t rocker- cls,ar2J1ce t o · 0 19 " ( • 4g;,;l.. For c h ec k.i ng . set r ocker c .Ie e rence to · 0 21" ( .53',,>

•

g

I

Fi t t e d f ro m Er.gine No . 9P- SA-Y i 40Q06

Fi t t ed to 1 275c c Midge t e nd Sp ri t e wi t il e ng i ne pre fix 1 2CC­

Fi t t e d t o a u t o ma t i c ve r s i o n s o f Mini or 1100 cang e

Pa r t No . 12G 729

N. B. See Mechanical Pa r t s List of apPI~priate vehicl e f orfu ll deta i l s of cha~g€points . e t c .

1.... ,.OftTANT , T~n",( o f t " " k'nd de.e ~ I l>.d on t h " t ~ . et ' . ... p n ... ly ...d"d..d b y fll ~ tHm~ 01 t~ ~

Wlrr ~ l'I ty 01 clot' veh 'c!e m~ ... uh n ", r t'r

.•...~ ' ,.' '.,-. '"'::- .-It - " . ~

".. ' ---: ' BM C . : -

'\"'- .~':..... -. " -

SPECIAL TUNING DATAIssued by: The BRITISH MOTOR CORPORATION LTD,

SPECIAL TUNING DEPARTMENT. Abingdon. Berkshire. England

Model GENERAL Sheet Z - 3 Issue 4

Ove rheat ing

Assuming tha t t he cylinder head ga ske t i s no t l eaking due to dis tortion andtha t the cccrect sparlcing plugs, i gnit ion timing and mixt ure a re being used , checkt he running t emperature w:it.'1 an a ccurately graduated gauge .. Note the boiling pointsunder pr essure - 5 Ib/ s q. in. 2260P , 7 lb/sq.in. 232op , 1 3 I b/ s q. in.. 246°F and r efe rto t he pres sur e on the c ap.

I f exces s i ve t emperatures a re c onfirmed, poss ible causes may be f ound amongstt he f oll owing paragraphs .

Examin e bot tom hos e 2A 245 o n •A' ser i e s engines i n c a s e h ea t e r outlet portionprotrudes int o t he mai n bore ~ Cut off surpl us wi t h a s ha r p knife or r epl ace i ft he r e is any s i gn of flaki ng . The water pump shou ld b e c hecked t o ensure clearancebetween vane and body is no more t han . 0 20 to . 030 in. ( . 508 to . 76 2 %>. The wat erpump 1nt ake Por e shoul d be as l a r ge as possible and the grinding of a s l i ght taperinto t he bOre' wi l l als o .a s s i s t flow. Ensu r e f an 'bel t t ens i on i s adequate .

AssUJ!ling t he thenoostat i s worki ng cor r e c t l y , ove rheating can r e s u lt if i t i sr-emoved wi-t hPut f i t ting bl anking s l e eve I l G 1 76 in i t s plac e . Al t emativel y , the by­p a s s cop~ection between the cylinder head and wat er pump may be s ealed on ' A' seriesengines.

If '~e car is f itted with a hea t e r , overheat ing in traff i c can o f t en beprevented. by opening t he wa ter valve and .running the heater so that t his a c t s a s anextra radia t o r . Fo r running under hot condi tions , i t may be desir abl e to f it at he rmos t a t which opens a t a l ower t empera t ure , s uch a s l3H 3584 ( 14

0C I l 6 5

0P ) .

After c ontinu a l u s e in dus t y conditio ns, the radia t o r cor e may become parti al l yb .Iccked ., possibly with l e a ve s and insects . Thi s can b e cleare d b y compres s e d ai r o ra j et of wa t e r used i n the opposi t e dire c t i on to norma l a i r flow.

Ob s t ructions t o air f l o w, suc h as b a dg e s, extra ligh t s and rally plat e s c an a l lc ause overheating, and should o bvious l y be r educ ed a s much as pos s i b l e . I f a sumpguard i s f i t ted , i t is es s ent i a l to use a l ar ge c a pac i ty o i l cooler . &, d this i sa l s o desi rabl e f or competit ion o r motonlay use. On. the Mini . coope r and Cooper ' S' ,use a cooler such a s that cont ained in kit C-A.JJ 3309. On the M.G.B. Midg et andSprite f ul l details of o i l cool e r install ation s are s hewn in the xecbanfcaf PartsLists, bu t a l arger M.G. B. eil c ool er i s a vailable to Pa r t No . C-ARO 9875 , andPart No. ARc 9809 can be f itted to t h e Midg e t and Spri t e .

On the Mini Cooper •5 ' , the radia tor eff i c iency h a s no w b e e n i mpro ve d bycha nging f rom 13 gi llS per i nch ( 25. 4 %l t o 16 gills per inch ( 25 . 4 %>. This mayb e che cked by counting vertically the number of horizo n t al fins i n a give n heigh tof t he radi a to r co r e . The l a tes t Part No . ARA 20 6 4 MUST be used with t he correctc a p ARA 16 33 and i mproved top hose 1 35 751 o n t he ' 5' o nly. This s ame rad i a t o rARA 20 64 and cap ARA 16 33 can al s o be u sed o n the Min i Cooper , but t op hosel 2G 10 4 mus t be u sed o n t his mode l .

For t he }fani r ange . 6 b l aded Fan 2A 998 and Sti££ener 2A 803 are t he mos tefficient f o r cooli..'"lg. Tne 1 6 bl aded P a n 1 2A 404 is qui e t es t , but f o r racing 1 or2 off 2 bladed Fan C- 2A 997 may be u s ed wi t h Sti.£f ener 2A 803.

The l a t e st t h e rmostat Pa r t Nos . are a s fo l lows :

130 35B4 (14°C , 165° F) . l 3H 3585 ( B2oC , 180oP ), 1 3H 3586 (88°C , 19 2o

P ) •

...fOOI,TANT: TUII"" du.. ktfld Mla'IMcl on chiaO. a... ty ududed b)' the tlIn\iII ddMI)V.rrlnt )' d ttt. .,ehlc!_ manufIcUI,..