Some may have seen my post where my generator failed me last weekend.

Having now pulled my old one down and looking at the one I was able to get as a replacement I have a couple of questions as I have noticed some differences.

If anyone has late 68 C40 Lucas on their Mini I would be interested to know if the D terminal (the larger one) is closer to the front or back of car when fitted and does it point up or down?

Also the Cooper S apparently had a larger pully. What size is it and what size is standard? Can anyone provide pics of a Cooper S fan and pully?

Cheers


Sent from my iPhone using Tapatalk

_________________

68 Morris Cooper S Mk1 (*ex 78 1275 LS 4th last built, 70 Morris 1500 OHC & 70 MiniMatic)

My large D terminal points down.



It is a C40 22704A with a large pulley.



The pulley is 4 inches across. No idea what size std is.

I had a google and found the following part numbers and application and some sizes. These are UK pulleys.

12G1054 = 2.75"
12A34 = 2.95"
12G2102 = 3.6" or 4"
12A1772 = 3.1"

Ok ta. The dynamo I had on and the replacement are both 3 1/4 in from memory so I'm guessing that's standard. I had an older dynamo with a big pulley 3 5/8 that I thought might be closer to cooper S size.

Shame that document doesn't show dimensions and I wonder where the measurement is normally taken for a pulley??


Sent from my iPhone using Tapatalk

_________________

68 Morris Cooper S Mk1 (*ex 78 1275 LS 4th last built, 70 Morris 1500 OHC & 70 MiniMatic)

Here is a NOS 12G2102 with 3.6" measured across the outer diameter. http://www.ebay.com.au/itm/252459177695

It will be interesting see what others have. My car is just charging at idle. Maybe my 4" pulley is too large.

And you say yours is 4in dia?


Sent from my iPhone using Tapatalk

_________________

68 Morris Cooper S Mk1 (*ex 78 1275 LS 4th last built, 70 Morris 1500 OHC & 70 MiniMatic)

Yes. I will recheck it again using my verniers.

Maybe Australia went up a size or two compared to U.K.?


Sent from my iPhone using Tapatalk

_________________

68 Morris Cooper S Mk1 (*ex 78 1275 LS 4th last built, 70 Morris 1500 OHC & 70 MiniMatic)

Rechecked with the verniers. 3.88". My ruler had some parralex error issues. Still a long way off 3.6". Sorry

Pulley size is set by RPM used if you rev the bollocks off it you need the larger pulley to keep the actual dynamo rev's down. A dynamo will come apart and destroy itself at high RPM hence the larger pulley to slow it down....................

997 and 998 Cooper had the big pulley also.

_________________
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.

Thanks. The one that was on the car was above the opposite brush and pointing up. Seems to be the odd one out looking at other cars now. Perhaps originally off a different model car. It was always a bit of a stretch for the wire so that explains why!


Sent from my iPhone using Tapatalk

_________________

68 Morris Cooper S Mk1 (*ex 78 1275 LS 4th last built, 70 Morris 1500 OHC & 70 MiniMatic)

Phill,

The Lucas C40 dynamo for a Cooper and Cooper S should be part number 22742 (stamped on the body) according to the parts book and some OS forum discussion.



The pulley for the Cooper and Cooper S is part number 1H998, superceded to 12G2102, and then AYH61 for the Australian equivalent.

For reference, the pulley for all other Mini models is part number 12A34 and AYG9029 for the Australian equivalent.

BMC Australia engineering drawings for both types shown below.

_________________
ex-NSW Police 1970 MK II Cooper S
VMCI #43

Great info Doug. Looks like my car has a Cooper Dynamo 22704A. I think i might go down a pulley size so i can get better charging in traffic and at idle.

I think you've misread the parts book. Dynamo 22704 is the one for all Minis except Cooper and Cooper S, which are 22742.

_________________
ex-NSW Police 1970 MK II Cooper S
VMCI #43