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A Derby Bentley in the making - Chris White
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| with a lot of imagination, an engineer's mind, welding and a missing purist's handbook . . . . . . . . . | |
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To
this? -
a Derby Bentley |
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| Below
is the story of the car in the making. We make no apologies for the way it is written, as it is a compilation of various email messages Chris has sent me over a period of time. As and when further progress is made, we will add more text to the bottom of the page. |
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Hi John, I have just broken a Bentley MkVI (1950). All I need is the chassis, everything else, including the front and rear axles, is for sale to anyone who may need spares. Do you know anyone who might want some Bentley bits?
Main components
are, engine (seized), gearbox, front and rear suspension/axle assemblies,
chrome-work, glass and winding mechanisms, seat frames, steering column
and wheel, assorted body panels, fuel tank (good condition), full
set of woodwork, and then there are all the little bits and pieces Hi John, The car I am building will be based on (looks-wise) a 1937 Derby Bentley with a Hooper cabriolet body
I want a car for Grand Touring in the traditional sense as I would like to tour Europe with my wife (I’m 50 next year so it is probably one of those hormonal crisis things). I love the look of vintage cars but, although I have a 20/25, I wouldn’t want to take one any distance – it is a challenge to drive which is great when you are in the mood but a pain if you want to relax and cover some miles.
The logic goes something like this:-
1 I want a car with taught handling – use a MkVI chassis because they are so rigid, unlike a Derby chassis, and get some modern suspension on it. (I got a totally dilapidated and rotted out barn-find) 2 I want a big lazy mile-munching engine - use a V8 3 I fancy a supercharger a la Bentley blower – use a Mulsanne turbo engine; dump the turbo and fit a supercharger in the traditional Bentley position. It will take a bit of fancy engineering, but I’m up for a challenge. I have procured a 6-71 GMC blower for which I will cast some new alloy end covers so that it looks period. I have also developed a clutch and inlet bypass system so that the supercharger can be turned off and run normally aspirated. 4 It seems sensible to keep the automatic gearbox – so I have lost the mechanical servo mechanism, which some would view as a step in the right direction. 5 I want 18” wires with vintage tyres so I need to change the diff ratio especially with the uprated engine. 6 Also, I need a brake upgrade as the mechanical servo disappeared with the gearbox! The answer to these problems is to fit an XJ6 independent rear suspension. It is all contained in a cage that can be easily rubber mounted to the chassis. There is a good choice of ratios and it has got to be lighter (and easier) than trying to fit a shadow/T series back end. The Jag diff can handle up to around 500bhp in standard form and, although it may not be the purist’s route, I think it is the best engineering solution. 7 I want front brakes to match the back brakes – fit an XJ6 front clip with ventilated discs and four pot callipers. I will hook it up to a pair of master cylinders with a balance bar and a pair of vacuum servos. I believe the cars ‘stoppability’ will be dependent upon the tyres rather than the brakes now.
To get the pre-war look it is necessary to either move the bulkhead back or the front wheels forward. I don’t want to ruin the cruciform design of the chassis so the sensible course seems to be to lop off the front of the chassis and cross-member and rebuild it with dumb irons. These will carry the Jaguar front clip which, surprisingly, suits a dumb iron style chassis. I also wish to increase the cabin length to make the car a conventional 2+2 rather than a 2+1 (sat sideways) The standard MkVI wheelbase is 120”, a Derby Bentley is 126” which would be the logical dimension to go to. However, as I wish to increase the cabin length, I think I will use the Silver Wraith wheelbase of 133”.
Once the chassis is sorted the front and rear suspension will both be rubber mounted which will nicely isolate the chassis from road noise. With rack and pinion steering, poly bushes all round and modern adjustable dampers it should be a fantastic ride. I can probably dispense with the rubber body mounts that the MkVI has as they won’t be necessary. This will provide a more rigid support for the timber bodywork.
The body will be coachbuilt from ash and aluminium. I have some wings from a 20/25 in the style I want; everything else will be built from scratch. It helps that I have got hold of an original set of drawings for the car.
That should be
enough for now and you can see why I have so much MkVI stuff to dispose
of. If any purists want to hang me be sure NOT to give them my address!
I’m not certain that this project would receive favourable comment
on your website, but the car was beyond restoration and at least it
will soon look good and be back be on the road! The demise of its
body may even contribute to saving some other MkVI’s (may be
getting a bit sacramental there?). ************* Hi John, A quick update for you.
I have the front and rear axles built up now. I have cut up (modified?) the rear suspension cage to fit the Bentley chassis. It will be rubber mounted and to this end I have fabricated a mounting for four rubber mounts that will bolt through into a plate mounted inside the chassis rail. To this end I have boxed the inside of the C section rail (Bentley had done half if it already!). The plates have been rough cut with a plasma cutter and will be dressed back once welded in place. This closing plate will carry a ¼” plate that will in turn carry the mounting bolts for the rubber mounts. The rear axle will then be stabilised with tie rods that will also be used to set the rear wheel alignment. I have also allowed space for shimming laterally to ensure that the axle is central in the chassis.
I have tacked into place the shock absorber mounts for the front cross-member. I have now got to build the chassis rails to carry it. The square box sections that you can see are drilled to the compressed length of the suspension with a car sat on it. This is so that I can build the thing without it slowly sinking as I add more weight. Once the car is finished I will weigh each corner and have springs made to suit. This will ensure the proper ride height for the vehicle.
When the fabrication is finished all the new work will be fully welded and the components dressed back into elegant shapes so that nothing looks ‘boxy’.
I am gong to break the engine unless someone wants it – so anyone out there wanting Bentley 4 ¼ engine bits – this is the place to come! ************* Hi John, Ok, if you don’t think it will cause a riot! I’m with you on the purist thing. A few people have contacted me about the MkVI via the site anyway and have asked what I’m doing with it. To date they seem interested and even enthusiastic. I had a really nice guy from Australia phone me who was also very complimentary about your site (by way of feedback). ************* ************* Chris White |
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