1 reply to this topic

[mrloaf]

Hello all,

 

I don't have a haynes, so I'm asking. What is the timing for a 1275 Cooper with a 23D4 dizzy (no vacuum advance)

and the rpm for setting the timing?

The dizzy was removed and rebuilt & now it runs a bit rough.

 

thanks

[KernowCooper]

This is all the information I have listed for your car

 

Mini Cooper S 1275cc (1964-71)

Engine   Type

• 12FA (Mk1, 2)
• 12H (Mk3)

Capacity 1275 cc (77.9 cu. in) Compression ratio (970cc) 9.71:1 Compression ratio (1071cc) 9:1

Firing order 1,3,4,2 Compression Pressure (High) 190 to 200 psi (13.36 to 14.07 kg/cm2)

Idling speed (approx) 600 rpm (approx) Fast idle 1000 rpm

Ignition timing (static) 2 degrees BTDC Ignition timing (600 rpm) 4 degrees BTDC Timing marks Dimples on timing wheels, marks on flywheel.

Valve rocker clearance 0.012 in (0.305mm) cold, 0.015 in (0.38mm) for competition.    

Distributor   Type Lucas 23D4 (no vacuum advance) Rotation of rotor Anti-clockwise Dwell 60 +/- 3 degrees

Contact breaker gap 0.014 to 0.016 in (0.35 to 0.4mm) Condenser capacity 0.18 to 0.24 micro-farads

Serial number 40819, 41033    

 

Centrifugal Advance   Decelerating check, vacuum pipe disconnected

• 28 to 32 degrees at 7000 rpm
• 22 to 26 degrees at 5200 rpm
• 10 to 14 degrees at 1600 rpm
• 6 to 12 degrees at 1000 rpm
• 0 to 3 degrees at 600 rpm

No advance below 450 rpm    

 

Spark Plugs  

Type

Champion Type N9Y Gap 0.025 in (0.625 mm)    

Ignition Coil   Type Lucas HA12 Primary resistance at 20 degrees C 3.0 to 3.4 ohms (cold) Current consumption 3.9 amps    

Carburettors   Type Twin SU HS2 Piston spring Red Jet size 0.090 in (2.29mm) Needle (standard) M Needle (rich) AH2 Needle (weak) EB

 

 

Edited by KernowCooper, 23 July 2013 - 10:31 PM.