So what are the differences between a MK1 and MK2 Cooper S Engine Block besides the engine numbers

_________________
1970 MK2 Cooper S

Mk 1 has a thin flange and M2 the thick flange (where the block meets the gearbox).

_________________
The bitterness of poor quality (or Crappy Workmanship) remains LONG AFTER the Sweet Taste of Low Price is forgotten.

And very early Mk1s reputedly were weaker around the centre main.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Do you know roughly up to what engine numbers? eg 9FSAY 38000

Some early Mk2 Cooper S's (my Mk2 is car number 336 and it has the thin flange block) also had the thin flange block but with the 9F/XE/Y engine number and reportedly some late Mk1's had thick flange blocks.
Probably fair to say that sometime in mid 69 there was a transition from thin flange to thick flange blocks - nominally around the introduction of the Mk2.

_________________
1967 New British Racing Green Mk1 Cooper S, 1967 Lake Green 1275 MG Midget, 1969 Jet Red / Crystal White Mk2 Cooper S, 1972 Gambier Turquoise Clubman GT (ex police), 1972 Camino Gold Clubman GT, 2009 JCW Challenge Edition, Megane RS265, Clio RS220.

yes this is true Rodmac.

_________________
The bitterness of poor quality (or Crappy Workmanship) remains LONG AFTER the Sweet Taste of Low Price is forgotten.

Keep in mind that the /SA/ refers to the gearbox type, 3 syncro and /XE/ refers to gearbox type 4 syncro.
I have also seen a lot of XE thin flange blocks but cant recall seeing a SA thick flange block. Not that it didn't happen, possible I guess.

_________________

The thick flange MK2 block I have has a stiffening rib adjacent to the dip stick hole.
The question is:
Do all thick flange S blocks have the stiffening rib?

RonR

_________________
68 build Mk1 Cooper S
72 Clubman GT project. Total restoration required