Thank you, readers for engaging with the puzzle I set during the summer and which I have so far neglected to return to. Relief is at hand!
The question was “What is the connection between the Opel Vectra “A” and the Rolls Royce Silver Seraph?” If you wish to find out the answer you must simply carry on reading.
The Opel Calibra was based on the Opel Vectra “A” which appeared in the market in 1988, as a saloon and hatchback (but not an estate). The Astra estate covered that market more than adequately plus the Opel Frontera was due in 1991 in both 3 and 5 door styles.
So, sans estate, the Vectra replaced the Ascona “C”. A year later the Calibra appeared in the European market, made first in Ruesselsheim, Germany, and later on at the Valmet factory in Finland. The Vectra had a 4-wheel drive option plus available V6 engines which meant the Calibra was able to make use of those features. (Ford, as usual, didn’t really bother to put up much against the Calibra until the Mk 2 Probe of 1993, a good 4 years later).
Turning to the other side of the pair: the Rolls Royce Silver Seraph. It had the naturally-aspirated BMW V12 fitted, which Car considered too noisy and high pitched. Bentley’s Arnage twinned the Rolls and received BMW’s 4.3 litre V8 as a means to distinguish it.
So, now the link between the Bentley and Calibra. The Arnage’s V8 engine bottom end was standard BMW stuff as were the four-valve twin-cam heads. The Arnage version of the V8 had a twin-turbo and the design for this was by Cosworth. Why Cosworth? Vickers, the owners of Rolls Royce and Bentley, owned that too.
Cosworth’s boffins used the same twin-turbo concept on the GM C20LET engine in the Calibra 4×4: “on each cylinder bank a water-cooled turbo housing is cast into the manifold itself” (Car, June 1998). With the turbo so close to the exhaust valves the throttle response could be faster as in the turbo would react more quickly to the exhaust gas flow than if it was situated further away. And presumably the exhaust gasses were hotter, reducing the tendency for the turbo to get caked with condensates and carbon.
So, that’s the link: Cosworth used the same concept for their work on the GM engine used in the Calibra as in the Arnage’s V8; the Vectra is related to the Calibra and the Arnage related to the Rolls.
Driven To Write 
My thoughts exactly but I didn’t think it would be that obvious.
Oh.
You got me, Richard! Of course i was aware of Cosworth’s involvement in the design (and the casting) of the C20XE head, but my german(!) sources from the period credit the turbocharged version to a team under Dpl. Ing. Ingo Janthur at Opel.
A quick patent search produced two relevant documents, the integral mainfold with turbine housing appears to be a Cummins invention,
GB2060066A, and Ing. Janthur appears as inventor in US4958600A, filled at the time for GM. It’s also interesting to note that asignee of the GM patent is a ‘Motors Liquidation Co.’, surely a consequence of the events of the 2008 crisis
I presume Opel bought the IP rights from Cosworth. And the team leader got the credit.
Good research: where is that data from, may I ask?
If you want to get into the nuts and bolts, or in this case, the concept of design, you can tie the Seraph to the Aston Martin DB7 Vantage via the ZF 5HP transmission.
That makes an longer chain: Vectra “A”, Calibra, Bentley Arnage, Seraph to Aston Martin DB7 Vantage.
I suppose a chain game could be made up of gearboxes and engines leading to a kind of Mornington Crescent for car enthusiasts.
You must be thinking of the 5HP50. I see the 5HP is mostly used on German cars but Jaguar have used it as well.
GM, Ford, Fiat, Renault and many others have steered clear. Why? Engines not big enough for it, I suppose.
PS I am glad to see someone showing some interest in this micropost.
Well, you did ask for the connection between the Vectra and the Silver Seraph. Perhaps if we’d all realized you in fact wanted to know the connection between the Calibra turbo and the Bentley Arnage instead, we could have had a better chance at solving the puzzle your way.
My reasoning through Cosworth, thanks to Robert, to Vickers as the owner of Cosworth and Rolls I regard as being the correct answer to your original question, rather than your reinterpretation of it.
Not even my dog-eared copy of Edward de Bono’s lateral thinking book of 50 years ago could keep up with you, Richard!
What is the difference between a dog? Both sets of legs are on the other side.