Pistons 1275 cooper S

Hello, je posséde des pistons plat "cooper S" année 1966 côte d'origine.
ref AEG 358 M39.
3 Segments et 1 racleur.
Qu'ont ils de plus ? le taux de compression ? puissance ?
merci de vos commentaires.

Beh ils sont plat...
Ce qui amene un peu plus de compression...
Pour le reste????

les bielles des cooper S etaient differents des bielles d'aujourd hui je crois. sinon les moteurs cooper s avait un cr de 9,75

la puissance des cooper s etaient donnée je crois pour 75ch pour les K1 et K2, les mk3 etaient donnée pour 71ch

titi de lille a écrit:

les bielles des cooper S etaient differents des bielles d'aujourd hui je crois. sinon les moteurs cooper s avait un cr de 9,75

la puissance des cooper s etaient donnée je crois pour 75ch pour les K1 et K2, les mk3 etaient donnée pour 71ch

Non, les MK3 ont egalement 75 ch, 71, ce sont les inno
bh

les mk3 ont une culasse en 29/36 comme les MG avec un CR de 9,75 alors que le MG a un cr de 10,5. donc je le vois mal faire 75ch comme les K2.

ceci dit avoir un bloc K1 ET K2 est une tres belle piece historiquement parlant

Pour ceux qui cause le british
Mk3 Cooper S Register

Probably the biggest single revision to the Mini range was the introduction of the Mk III bodyshell. Although the Mk III Mini had been introduced in the autumn of 1969, Mk III S production did not commence until March 1970 and the first cars were not dispatched until the beginning of May. This is allegedly down to legal wrangles because BMC and John Cooper had an agreement for Cooper S’s to be produced for five years from the middle of 1966 and Cooper refused to be bought off by BL when they were trying to dispose of all such agreements in 1969.


One thing that did carry on with the Mk III S was hydrolastic suspension. Standard fitment were ‘silver’ units which were, in effect, competition units. These are considerably stiffer than the standard ‘green’ units found on more mundane models and much reduce the seesaw effect felt under acceleration and braking. It is said that the Mk III S has the best ride and handling of any production Mini.
When the Mk III S did finally appear it was a virtually indistinguishable from a Mini 1000, the only external clues being the twin petrol tanks, wheels and boot badge - all easily missed by the untrained eye. Gone was the different grille, two tone paint and different badging. Internally the main clue was the 130mph speedometer. One thing that was unchanged was the level of performance, despite the lack of an EN40B crankshaft which was dropped on cost grounds, power output was still quoted at 76bhp. This made it an ideal Q car and Liverpool police confirmed their faith in the S by taking delivery of 27 Glacier White cars in early 1971.


Because of the short production run changes were relatively minor, the main one being the fitment of a locking steering column at the end of 1970 and some colour changes. When production ceased at the end of June 1971 only some 1572 Mk III Ss had rolled off the production line which makes it a limited edition by modern standards. That it sold as many cars as it did was a testament to the Cooper name as BL never advertised the car and even the sales brochure was only a retouched version of the Mk II S brochure.


Good original cars are getting harder to find but a surprising number of cars have been with one owner from new. Because of the external similarity between the Mini 1000 and S the Mk III is one of the easier models to recreate and with prices for good cars are still holding up well buyers should always beware. Thanks to co-operation with British Motor Industry Heritage Trust at Gaydon the register has identified virtually all Mk III S cars produced from their chassis numbers. The MCR would always recommend that you check out any car with the relevant registrar before you buy.

bh

titi de lille a écrit:

les mk3 ont une culasse en 29/36 comme les MG avec un CR de 9,75 alors que le MG a un cr de 10,5. donc je le vois mal faire 75ch comme les K2.

ceci dit avoir un bloc K1 ET K2 est une tres belle piece historiquement parlant

Il semble que seule les MK1 avez des soupapes ech en 31 et guides bronze, les culasses ont etaient changées par la suite car il y avait un probleme de casse, les MK2 ont donc une culasses en 29 avec des guides acier comme les MK3 et Les inno, avec un AAC aeg 542 comme toutes les S(sauf les inno bien sur)
Pour les MG un seul carbu, AAC different et echappement olé olé
Le bloc des MK1 et MK2 est bien comme tu le dit, une piece historique devenu presque introuvable et a un prix souvent abusé.
Pour les piston ,sur les 1275, ils sont concaves, je pense que ceux cités plus haut sont des pistons de 970 ou 1071, ceci pour compenser la perte de RC car toutes les culasse de S ont un meme volume, mais ceci est a confirmer, mon disque dur ou j'avais toute ma doc a rendu l'ame, je doit maintenent faire des recherches sur papier.
BH

bh a écrit:

Pour ceux qui cause le british
Mk3 Cooper S Register

Probably the biggest single revision to the Mini range was the introduction of the Mk III bodyshell. Although the Mk III Mini had been introduced in the autumn of 1969, Mk III S production did not commence until March 1970 and the first cars were not dispatched until the beginning of May. This is allegedly down to legal wrangles because BMC and John Cooper had an agreement for Cooper S’s to be produced for five years from the middle of 1966 and Cooper refused to be bought off by BL when they were trying to dispose of all such agreements in 1969.


One thing that did carry on with the Mk III S was hydrolastic suspension. Standard fitment were ‘silver’ units which were, in effect, competition units. These are considerably stiffer than the standard ‘green’ units found on more mundane models and much reduce the seesaw effect felt under acceleration and braking. It is said that the Mk III S has the best ride and handling of any production Mini.
When the Mk III S did finally appear it was a virtually indistinguishable from a Mini 1000, the only external clues being the twin petrol tanks, wheels and boot badge - all easily missed by the untrained eye. Gone was the different grille, two tone paint and different badging. Internally the main clue was the 130mph speedometer. One thing that was unchanged was the level of performance, despite the lack of an EN40B crankshaft which was dropped on cost grounds, power output was still quoted at 76bhp. This made it an ideal Q car and Liverpool police confirmed their faith in the S by taking delivery of 27 Glacier White cars in early 1971.


Because of the short production run changes were relatively minor, the main one being the fitment of a locking steering column at the end of 1970 and some colour changes. When production ceased at the end of June 1971 only some 1572 Mk III Ss had rolled off the production line which makes it a limited edition by modern standards. That it sold as many cars as it did was a testament to the Cooper name as BL never advertised the car and even the sales brochure was only a retouched version of the Mk II S brochure.


Good original cars are getting harder to find but a surprising number of cars have been with one owner from new. Because of the external similarity between the Mini 1000 and S the Mk III is one of the easier models to recreate and with prices for good cars are still holding up well buyers should always beware. Thanks to co-operation with British Motor Industry Heritage Trust at Gaydon the register has identified virtually all Mk III S cars produced from their chassis numbers. The MCR would always recommend that you check out any car with the relevant registrar before you buy.

bh

arghhhhhhhh GH, je n'aurai pas du lire ça

moi qui suis né en septembre 71, ça me prouve encore une fois que c'est le modèle idéale trop rare et recherché

Salut arnaud,

Moi je pense surtout qu'ils apportent de la "lourdeur" à l'ensemble.
J'ai trouvé l'origine de mes pistons 1293 à 4 segments comme les tiens, ils sortent tout droit des années 60-70, et sont beaucoup plus lourds, épais et longs que les récents.
Ils restent pourtant des pièces "old school", pour rester dans la pure restauration d'anciennes ...
Les segments se trouvent chez les rectifieurs qui veulent bien se donner la peine de chercher dans leurs stocks.

apres renseignements pris sur les pistons de greg effectivement depuis ils ont fait des progres en la matiere; en termes de nombre de segments (3 au lieur de 4) et de poids et donc longueur comme tu le dis
concretement à part pour rester dans l'esprit d'un moteur d'origine ça n'a pas grand interret de réutiliser ce type de pistons

oui, mais ces pistons ont tournés au Monté Carlos en 1966 source sure.