MkI, MkII & MkIII-70s & onwards usage

[rstainer]

This string is for those interested in 70s and onwards Cobra descriptors (with issues lifted from the string that seeks further evidence regarding AC’s 60s terms).
   
   At least two issues arise. In 70s and later terms:

Is a MkI a worm and sector car, or a 260?

Is a 427 a MkIII or not?

   ‘It's my understanding that MkI referred to the worm-and-sector leaf-spring Cobras, MkII were the rack-and-pinion leaf-sprung cars, and MkIII were the coil-sprung cars. Engine size was not the defining characteristic. Even if these were common references, not official factory labels.’ (SunDude)
   
   ‘.....in the 1970's / 80's ordinary members always referred to Mk1 Cobra's as the 260 engined cars, Mk 11 as the 289 cars and Mk 111 as the 289 coil sprung cars.’ (John Murch)
   
   Perhaps SunDude, John Murch, Steve James, Trevor Legate and others could produce a collectively acceptable answer?

[rstainer]

Trevor Legate: '.....was there ever a Cobra Mk I?'
   
   For the historical evidence see AC's period AC 289 Sports advertisements (ACOC archive).
   
   Their wording together with other available evidence was published in ACtion in 2003, as stated in the 'Thames Ditton MkIII Cobra' opening post.
   
   Robin Stainer
   ACOC Cobra registrar

[nikbj68]

I had always thought of MkI running up to CSX2128, when the Rack & Pinion steering was adopted, but I honestly can`t recall why or when I took that assumption, but I never heard or used the term 'slabside' until the internet came along! (and still don`t, given the choice!)

[SunDude]

Robin,
   
   I've seen people use both engine (260, 289) and steering system (worm-and-sector, rack-and-pinion) to differentiate between MkI and MkII Cobras.  However, on p. 1598 of the 2008 SAAC World Registry, they define MkI as worm-and-sector and MkII as rack-and-pinion for the leaf-sprung cars.  You might want to drop a line to Ned.
   
   Brian

[A-Snake]

quote:Originally posted by nikbj68
   
I had always thought of MkI running up to CSX2128, when the Rack & Pinion steering was adopted, but I honestly can`t recall why or when I took that assumption, but I never heard or used the term 'slabside' until the internet came along! (and still don`t, given the choice!)
   

   
   Pedant comment...[)]  Nik, I'm sure you meant to type CSX2126, right? []

[nikbj68]

Appreciated, Mr.Snake... Yes.

[aaron]

Does it really matter  ?
   
   In my files of thousands of Cobra photos, I refer to the first 75 Cobras as 260 cars , the rest of the CSX2000 cars as 289 Cobras, and the CSX3000 cars as 427 Cobras ,plus a file of all the other cars.
   
   I refer my photos of the AC 289 cars in another folder , even though they were built on the 427 chassis with a 289 engine ! Suits me Sir ![][][][][]

[rstainer]

The posts on this and the previous string, plus a little more research, show three schools of thought.
   
   One is that the term ‘Mk’ need not be applied to Thames Ditton Cobras at all. This is the line taken by AC and Shelby American in period, where it was never used in the marketing of any of their products, and by the SAAC and ACOC period Cobra registrars.
   
   The second, widespread, is based on classifying by AC chassis engineering changes:

MkI = leaf spring worm & sector

MkII = leaf spring rack & pinion

MkIII = coil spring

   The third, much less common, is based on classifying by Ford engine model:

MkI = 260 (leaf spring)

MkII = 289 (leaf spring)

MkIII = 427 (coil spring)

MkIII/289 = 289 (coil spring)

There are variants to this less common school: some, for example, say that a MkIII is 427 and that an AC 289 is an AC 289 (no Mk designation), others that a  MkIII is a coil spring 289 and that a 427 is a 427 (no Mk designation).
   
   The widespread AC chassis engineering change classification carries much greater authority than the engine model classification. The engineering designation was agreed by John Rimer (ACOC Cobra Registrar) and Bill Kemper in 1971 and used in the earliest SAAC and ACOC Cobra registers.
   
   The earliest knowledgeable use I have of the less common Ford engine model classification is in Trevor Legate’s 1984 ‘Cobra’ (p48, 104, 124 etc). This classification leads to rather odd conclusions, such as 8% of MkIIs having worm & sector steering & fabricated front uprights and 92% having fundamentally different arrangements.
   
   Ned Scudder and I avoid all these complications by classifying the SAAC period and ACOC Thames Ditton Cobra registers into Leaf Spring Cobras and Coil Spring Cobras (Shelby and AC kept separate); neither register uses the ‘Mk’ word in any car or model description.
   
   The simplicity and clarity of the terms leaf spring & coil spring, worm and sector & rack and pinion, 260, 289 & 427 lead me to suggest that the term ‘Mark’ is best not applied to Thames Ditton Cobras at all. It should be reserved for products that are branded ‘Mk’ or ‘Mark’ by their manufacturers. Neither AC Thames Ditton nor Shelby American in period ever used Mk as a brand; however in later times Angliss, Lubinsky, Gullwing and Superformance have all use Mk as a marketing brand.

[3.5 Pints at the Bar]

I've always found this whole topic confusing. Back in the 1980s, some letters received from Thames Ditton had a reference to the AC trademark being used by licenced users "3000ME and Mk III 289". I assume the 3000ME was the AC Scotland version, but I didn't understand the Mk III 289 reference.