Engine and Bore Size |
Ring including oil ring
and ring size |
Ring Hepolite part number. |
Rings Rover part number STD/20 only |
Piston Part Number |
Piston shape |
Remarks |
850cc
62.916mm 2.477” STD 20/ 30/ 40/ 60 |
4.
3 x 0.0700”
1.778mm
1 x 0.1250”
3.175mm |
RA8576
|
BHM1161
|
12A120
|
|
Use 15037
|
5.
3 x 0.0700”
1.778mm
1 x 0.1248”
3.170mm
1 x 0.1250”
3.175mm |
RA8577
|
|
15037
|
|
|
Cooper - 997cc
2.458” - 62.43mm
STD 20/ 30/ 40/ 60 |
4.
3 x 0.0625”
1.588mm
1 x 0.1250”
3.175mm
|
2C6724
Hastings ring
|
|
12A212
15799
18515 |
|
|
Cooper
998cc
2.542”-64.567mm
STD 20/ 30/ 40/ 60 |
3.
2 x 0.0625”
1.588mm
1 x 0.1575”
4.000mm |
R39400
can use R33636 |
|
20950
was 18516 |
Flat top 20950
9.7 CR |
Powermax
Rings also fit 18516 |
4.
3 x 0.0625”
1.588mm
1 x 0.1250”
3.175mm |
R32026
or C-STN99 |
BHM1162
|
12A674
|
Flat top with
raised ‘D’ |
|
998cc
64.567mm
2.542”
STD 20/ 30/ 40/ 60 |
4.
3 x 0.0625”
1.588mm
1 x 0.1250”
3.175mm |
R32026
or C-STN99 |
BHM1162
|
12A673 / 16309
|
Dished piston 8.3
|
To 1979
|
4.
3 x 0.0625”
1.588mm
1 x 0.1575”
4.000mm |
R33636
|
BHM1281
|
ADU3920
20754 |
Flat top 10.3 to 1 CR
|
1980 on, until changed
to 3 ring piston |
4.
3 x 0.0625”
1.588mm
1 x 0.1575”
4.000mm |
R33636
|
BHM1281
|
ADU3922
20773 |
Dished 8.3 to 1 CR
|
3.
2 x 0.0625”
1.588mm
1 x 0.1575”
4.000mm |
R39400
can use R33636 |
BHM1415
|
ADU3490
|
Flat top 10.3 to 1 CR
|
3 ring pistons up to
introduction of press
fit gudgeon pin, 1988
|
3.
2 x 0.0625”
1.588mm
1 x 0.1575”
4.000mm |
R39400
can use R33636 |
BHM1415
|
ADU4203
20536 |
Dished 8.3 to 1 CR
|
3.
2 x 0.0590”
1.499mm
1 x 0.1181”
3.000mm |
|
BHM1629
|
TAM2052 (Rover)
P22463 (AE) |
Flat top stamped 21964
|
Press fit gudgeon pin
only 1989 on
|
3.
2 x 0.0590”
1.499mm
1 x 0.1181”
3.000mm |
R43240
|
|
TAM2054 (Rover)
22464 (AE) |
Dished stamped 21965
|
1100cc
64.567mm
2.542”
STD 20/ 30/ 40/ 60
|
4.
3 x 0.625”
1.588mm
1 x 0.1249”
3.172mm |
R32026
or C-STN99 |
BHM1162
|
12G758
use 20397 |
|
Morris Minor/ Mini/ MG 1100/ Sprite
Clubman 1975-1980 |
5.
3 x 0.0625”
1.588mm
2 x 0.1250”
3.175mm |
R17927
|
|
Not Mini
16179 |
|
Morris Minor/MG 1100/Sprite
5 ring 1975-1976 |
4.
3 x 0.0625”
1.588mm
1 x 0.1575”
4.000mm |
R33636
20397 |
BHM4418
|
|
Dished
20397 |
Morris Minor
MG 1100/Sprite |
1275cc
70.625mm
2.780”
STD 20/ 30/ 40/ 60 |
4.
3 x 0.0625”
1.588mm
1 x 0.1575”
4.000mm |
R21576
|
BHM1164
|
17271 (AE)
|
|
1275GT and
1275cc non ‘S’ |
4.
3 x 0.0625”
1.588mm
1 x 0.1575”
4.000mm |
R21576
|
BHM1284
|
20394 (AE)
|
Dished 8.8 CR
|
1275GT and
1275cc non ‘S’ |
3.
2 x 0.0591”
1.501mm
1 x 0.1575”
4.000mm |
R35960
|
|
|
Dished 8.8 CR
|
Latest metric sized piston
1275 GT 1970-1975 |
4.
3 x 0.0469”
1.191mm
1 x 0.1575”
4.000mm |
R19520
|
BHM1165
STD/20 oversize |
AEG143
|
Dished 9.7 CR |
Original ‘S’ and
1300GT. Use 21253 |
3.
2 x 0.0625”
1.588mm
1 x 0.1575”
4.000mm |
R26686
use R21576 |
BHM1166
|
19320
|
Dished 9.7 CR
|
Later ‘S’ and
1300GT / 1275GT |
3.
2 x 0.0591”
1.501mm
1 x 0.1181”
3.000mm |
R41570
C1818 (Steel ring upgrade) |
BHM1628
|
21253 (AE)
TAM2050 (Rover) |
Dished 9.7 CR
Stamped 21962 |
Metric sized pistons
Dished 10.1 CR |
3.
2 x 0.0591”
1.501mm
1 x 0.1575”
4.000mm |
R35960
|
|
21250 (AE)
TAM2048 (Rover) |
Dished 9.4 to 1 CR
Stamped 21963 |
Metric sized pistons
|
3.
2 x 0.0625”
1.588mm
1 x 0.1575”
4.000mm |
Use R21576
|
BHM1260
|
ADU5704
was P22357 |
Turbo Dished 9.4 to 1 CR
Known as 21254 |
Use P223575 + 40 only available
|
2 x 0.0470”
1.194mm
1 x 0.1575”
4.000mm |
C-AJJ3379
|
|
ADU5704
was P22357 |
Turbo Dished 9.4 to 1 CR |
P223575 + 40 only
AE MEGA type |
2.780”
70.625mm
Powermax
STD
+20/40/60 |
3.
2 x 0.0469”
1.191mm
1 x 0.1575”
4.000mm |
R39380 C.W.E
Can use R19520 |
|
18517
18518 |
Dished 9.7 CR
Flat top |
Forged, use 20747
Use 21882 |
3.
2 x 0.0469”
1.191mm
1 x 0.1575”
4.000mm |
R39380 C.W.E
Can use R19520 |
|
20747
|
6.6cc Dish
9.7 to 1 CR |
AE413
Squeeze cast - 16906 |
3.
2 x 0.0469”
1.191mm
1 x 0.1575”
4.000mm |
R39380 C.W.E
Can use R19520 |
|
20739
|
Flat top
|
Squeeze cast,
use 21882 |
3.
1 x 0.0394”
1.000mm
1 x 0.0469”
1.191mm
1 x 0.1181”
3.000mm |
R41720
|
|
21882
|
Flat top
|
Squeeze Cast |
AE-MEGA / OMEGA
2.780mm |
2 x 0.0470”
1.194mm
1 x 0.1575”
4.000mm |
C-AJJ3379
|
|
C-AJJ3378 AE/MEGA
C-AJJ3382 AE/MEGA |
Dished
Flat top |
OMEGA are Hi-grade cast light alloy.
AE MEGA were squeeze cast - now
new technology castings, FM-B2
material double heat treated |
AE-MEGA / OMEGA
73.5mm |
2 x 0.0470”
1.194mm
1 x 0.1575”
4.000mm |
OMEGA
R73.5 |
|
See special tuning
|
7cc dish - C-STR310
11cc dish - C-STR312 |
Powermax 73.5mm
1275 to 1380cc |
2 x 0.0591”
1.501mm
1 x 0.1575”
4.000mm |
R39390
|
|
P20659 (AE)
C-STR311 (Minispares) |
Dished 9.6 CR
9cc Dish |