Some nice photos with this article:
Some nice photos with this article:
Six Cylinder Cam Followers/Tappets are available from:-
Arrow Precision Ltd
12 Barleyfield Services
Hinckley Fields Industrial Estate
Leicestershire LE10 1YE
Tel: 0044 1455 234200
Available on-line under Part No. CF124. However the prices have risen sharply but if sets [only availble in sets of 12] are ordered through Pegasus, we can supply at a better price.
Also available are racing cam followers which have a special diamond coating but see comment above.
By the way, the tappets for the 406 are a larger diameter. Bristol cars used to supply but it is not known if they still do. Arrow do not make them.
Please find contact details of the Furflex/draught excluder supplier:-
William Marston Ltd
70 Fazeley Street
Tel: 0044 121 643 0852 or 0044 121 643 0372
The boot seals can possibly be obtained from:-
Unit c1a Langlands Business Park
Devon EX15 3D4
Contacts: Nigel or Kaye Coles
Tel: 0044 1884 849294
Woolies (I & C Woolstenholmes Ltd)
Northfields Industrial Estate
Tel: 01778 347347
Both of these companies carry a large range of extruded sections and just may be able to help with boot and door sections.
I had all three of my carbs rebuilt last year by:
28f High St, Leighton Buzzard, LU7 1EA, Tel 01525 371369
They did an excellent job and the cost was £250-300 for all three – not cheap but kit now like new. They quoted 6-12 weeks for work to be done.
Ed. Extract of services provided pasted below as taken from their website Oct 2013
Over the past 80 years or so there have been innumerable carburetter designs by many different manufacturers, and it would be impossible for us to compile a detailed rebuild procedure for each one. However, all carburetters tend to follow the same principles of design, enabling us to give an indication of the various processes involved.
* Denotes concours service only.
Carburetters are now re-assembled using all new wearing components, i.e.:
Any other components found to be faulty will be replaced. All internal components are adjusted and set as per manufacturer’s specification. Carburetters are then engine tested to ensure correct functioning of the following:-
Fuel level, Idle circuit, Choke mechanism, By-pass circuit, Pull down and fast-idle operation, Progression circuit, Correct throttle operation, Main circuit, Correct response to mixture adjustment, Pump circuit.
(Upon re-fitting to vehicle, normal adjustments will be necessary)
Carburetters are given a final inspection and guaranteed for 12 months.
The age old question for classic car owners is whether to fit a modern audio system that pleases the ear or a period radio that pleases the eye. Stuart Risebrow has attempted to “have his cake and eat it” by fitting a modern audio system with period looks.
This unit, manufactured by “Retrosound”, a USA company, was found to be perfect for the job. You have a range of period bezels and knobs to choose from that replicate the look of classic radios such as radio mobile and Phillips. However, the two rotating switches are detachable, allowing bespoke placement as well.
You will see that Stuart chose to make up a plywood insert to fit the mounting whole in the dash which he then veneered himself in walnut before adding a polished lacquer finish.
The “Retrosound” radio also comes with a small auxiliary unit that is wired to the rear of the radio and located remotely. This allows you to plug in an SD memory card, USB storage device or 3.5mm audio jack. The SD card allows you to store 1000’s of songs which is perfect for all those 60’s hits and Glen Miller tracks! Stuart placed my remote unit just inside the glove box. You would hardly know it was there.
The radio itself has an inbuilt amp that provides plenty of “oomph” and has all the expected outputs for larger amps, aux players or an electric ariel.
Dave Dale and John Lawley both place great faith in Castrol Classic XL 20/50.
John Lawley, BODA technical officer, has more recently been using another oil also developed especially for classic cars. If you go to http://www.commaoil.co.uk/productsguide you will see 3 versions: a combined winter/summer oil, a dedicated winter oil and a dedicated summer oil. I use the combined version and have been very satisfied with it.
The only reason for the change is that my current motor factor does not stock the Castrol oil only obtaining it to order. However, they stock the Comma oil so I thought I would give it a try.
This company can supply any of the Bristol key patterns, either as a duplicate or to a code. The code can be found on the barrel of the lock. This does entail removing the barrel from the lock.
Unit D1/D2, Pinetrees Road, Pinetrees Business Park, Norwich, Norfolk, NR7 9BB
Worn butterfly spindles are sometimes the cause of erratic and unstable tick-overs. Replacement spindles and re-bushed bodies seem to be the only cure. Even then it becomes a good policy to blank off the non linkage end of the housing with a brass turned cup tapped home. To provide an air tight seal the linkage face may be sealed with a thin small diameter ‘0’ ring.
When the butterfly is in the closed condition, the mixture signal will be improved via the mixture screw. Also any fuel dribbling down the choke tube will not leak out via the spindles resulting in a much cleaner carburettor.
When a hot engine is switched off there is a sudden heat rise into the carburettors. This causes the fuel to boil which expands and is now forced up the emulsion tube then down to the butter fly hence leaking fuel out of worn spindles. Heat rise has always been a problem with all Bristol engines, 6 cylinder and V8s. ‘Tufnel’ or ‘Packsalin’ insulation plates provide an excellent barrier to this heat rise. The main body, on later V8s, was even made from ‘phenolic resin’ in an attempt to prevent this heat rise. These insulation plates are 0.062” or 1.5mm thick with the required gaskets. One is fitted direct to the head with a gasket top and bottom and then the fulcrum bracket is put on, a further green gasket, then the second insulation plate and then the grey gasket, finally the carburettor. When fitting the carburettor assembly to the head, do not forget the mounting flanges must be flat. Do not over tighten the thin retaining nuts, they can warp the flanges.
Note, the information in the handbook or workshop manual is only correct at the time when it was written. It does not apply now ie the jet sizes quoted are for standard engines on 82-3 octane fuel. Most engines are not standard by any means so, with heads that have been skimmed and distributors that are no longer accurate, engines will not be giving their best power. For an incremental rise in compression so must a change in the size in jets be considered.
Consider one 320cc cylinder using 83 octane fuel, the compression could be 8.5: l. For the same cylinder with a refurbished head that may have been skimmed and now running on 93-5 octane fuel, the compression could be as much as 10:1. What you really need to know is the clearance volume in the cylinder head to determine the compression ratio. This is when you need to look at your jet sizes. I know this is not easy, in fact it took BCL some time to finalise these settings. A word of warning; if receiving any rebuilt carburettors, strip and carefully reassemble them yourself. This was always done at BCL. It has been known for carburettors to arrive with different needle valves in one to another, different thickness washers one to another, throttle plates not centralised, etc. The choke plate will require lapping if it is to function at its best.
Also remember that fuel density is dependant on its temperature so the hotter the fuel the weaker the mixture. Remember, on fuel injected cars, fuel is in constant circulation in an effort to maintain this density.
Fuel pump pressure. Ex works, fuel pumps were always stripped and adjusted before fitting. Make sure yours is right, 2psi is about right. How? Drill and tap the front banjo bolt, fit screwed tube, connect to a sensitive low pressure gauge and observe the pressure reading, adjust the large fuel pump spring until correct. Remove the screwed tube and replace with a blanking bolt.
Starting from cold, the load on the starter motor and battery can be eased considerably by fitting an electric fuel pump. An ordinary SU fuel pump fitted in the fuel line with a manual electric switch with a warning light should ease this problem. How? From the delivery side of the fuel tap take a flexible pipe to the inlet side of the SU pump, from delivery side of the pump connect to the inlet side of the AC mechanical pump. Now just switch on then wait for the SU pump to stop ticking, switch off – instant engine start. Why? Carburettor float bowls are full and ready to go. Before with float bowls nearly empty it took a little while for them to fill. This is why a priming leaver is fitted to the AC pump.
Whatever fuel you use or condition your engine is in, the ignition must be adjusted accordingly. Marks on flywheels, or bits of metal and marked front pulleys are of very little use in this changed situation; usually a slight retarding is required. Remember your distributor was recommended for replacement at 40,000 miles or so. So how is yours?
The Bristol Owners & Drivers Association is a Member of the Federation of British Historic Vehicle Clubs. Bristol Owners & Drivers Association Ltd is a company limited by Guarantee of £1 per member.
Registered Office: The Old Sawmill, Shawbridge Street, Clitheroe, Lancashire, BB7 1LY
Company Registration No. 07270546. Data Protection Registration Z2297300
This website is the copyright of the Bristol Owners and Drivers Association Ltd.