No fixings under the back seat of Old Blue apart from a clamp and nut to hold the battery steady.

Old Blue wrote:

12v cars are different.

Rattletrap wrote:

I doubt there's any real difference in the battery fitting on a 1967 6volt and on Old Blue, a 68 12volt.

Old Blue wrote:

I still think that a tryout 12volt car section would be a good idea. There must be a few members that have complete stock 1968 on cars who would love to interact about them. Yet there are people posting images of non stock pre67 cars on some threads!

Old Blue wrote:

Just how long is it before petrol becomes 'stale'

Rattletrap wrote:

Stihl,a leading German small engine manufacturer.Claim in their literature,petrol starts to lose it's qualities from as little as three months.

GKL 7 wrote:

Stihl,a leading German small engine manufacturer.Claim in their literature,petrol starts to lose it's qualities from as little as three months.

GKL 7 wrote:

The lighter fractions of the fuel blend are lost namely butane and pentane reducing the volatillity. It kind of goes flat.

harveypj wrote:

It does get a bit complicated, you might want to sit down
I do not claim to be any sort of expert but I have picked up a basic understanding during my 18 years working in refinery operations.
Petrol is a blend of HydroCarbons, molecules made up of Hydrogen and Carbon atoms ranging from butane (4 carbons with 10 hydrogens) C4 for short, up to around C12 (doedecane) in all their varing forms plus various addatives to promote stable burn and detergants. Butane is the lightest (an LPG) and basicaly wants to be a vapour from about 0 degs, so is first to escape. Petrol blended for winter/cold climates has a higher butane content.
Pentane (C5) is next.
Different fuel blends have different combustion characteristics, some will auto ignite prematualy in a rapid uncontrolled manner as they are compressed (described as Knock - can be heard as 'pinking') this is more severe the higher the compression ratio of the engine, some blends will be more resistant to this and can be burned efficiently at higher compression ratios that is favourable for higher power outputs.
The octane rating of a fuel is a referance number, awarded when its 'anti knock' characteristics are the same as that of a standard reference fuel blend.
2,2,4-trimethylpentane (an isomer of Octane) is rated as 100 and sets the standard. Our regular unleaded has a Ron (research octane number) of 95, equivalent to a blend of 95% Iso Octane and 5% Normal Heptane (heptane is rated at 0)
This is where it can get a little complicated, hydrocarbon chains in their simplest form are straight chains or 'normals' or in more complex forms as branched or ring chains known as 'isomers' . So in the case of our 2,2,4 above; a chain 5 long (pentane bit) with 3 branches (tri) 2 at the second link and 1 at the fourth link (2,2,4)......simples😬
isomers have a higher rating compaired to their normal brothers.
The the octane rating is not a measure of how much energy the fuel contains but its resistance to autoignition when squeezed.
The Beetle engine is a long stroke low compression engine (somthing around 6:1) so can run happily on standard petrol (3 star in its day), running high octane stuff will not give you any more power. A modern high compression engine with knock sensor/adaptive engine management will however burn it to better effect.

harveypj wrote:

May I add my two-pennyworth !
Assuming the confirmed health/efficiency of the starter motor I would first of all ensure all ignition components are fit, then check the actual ignition timing : a couple of degrees retarded and sluggish turning over and a reluctance to fire could be mistakenly blamed on the battery.
The traditional hand-held "Load" tester comprises a heavy metal spring or coil resistor mounted between two "Prongs" with insulated handles between which a voltmeter is also fixed. Pressing the two probes onto the battery terminals simulates the load that the starter motor imposes, the voltmeter indicating the reduced power available to energise the ignition circuit.
Two points about the load tester : The voltmeters are usually of a " Centre Zero " type, the needle swinging away from the prong on the positive pole of the battery ( Handy to check terminal polarity !) and most "Load" or "Drop" ( ie Voltage Drop" ) testers are stated to be suitable for use on batteries up to SIXTY ampere/hour capacity, lower than the capacities of six-volt batteries for VW's ! Accordingly, a low or poor test on a 6-volt VW battery is more-ominous than a similar reading on a smaller six-volt. This type of tester should only be applied for a similar time to that during which you'd expect the vehicle to have started.If the voltage reading continues to "Sink" after three or four seconds on a fully-charged battery then watch for a cell to "Short" or "Gas" ( And Smell !)
The best check for a battery's state of charge is to use a small volume/capacity hydrometer
which indicates the acid's specific gravity ( Small hydrometer because there's not too much acid in each cell from which to draw a test sample!). Avoid contamination by trying not to transfer residual amounts of acid from one cell to another.
At normal room temperatures ( 20 C to 25 C ) a healthy gravity between 1.250 and 1.280 is ideal. Readings between 1.200 and 1.240 indicate partial discharge and a charge-up needed but lower than 1.200 point to a flat battery and longer charge needed. Some hydrometers have colour-coded zones indication acid strength ( High, Medium or Low)
A battery will give a false load-test result if the gravity is below 1.240. If you have a variable charge RATE ( Not 6 or 12 volt ) charger ( ie High or Low settings ) it is advisable, especially in cold weather, to commence charge at a low amperage
There being only three cells to compare on a six-volt battery, variations in gravities are harder to detect than on six-cell 12-volts. Variation between cells of 0.1 s.g. or more after charging are usually indicative of a suspect cell which will "Gas" visibly when load-tested. After charging and prior to load test, remove the three cell filler/vent caps and blow across the battery lid to dissipate the explosive hydrogen given off in the charge process.
Always abide by the golden rule to prevent sparking an explosion ! Starting charge : Crocodile clips on to battery then switch on charger. When finished : Switch OFF charger then remove crocodile clips ! No unexpected sparking nor loud, corrosive bangs !
Off on a tangent, many modern sealed batteries boast a "Magic Eye" charge indicator. This is a simple optical float hydrometer device calibrated to float green when OK, usually yellow when part discharged and clear with a red circle or plain black when discharged. Bear in mind that this device only indicates the state of charge of that ONE cell, not the whole battery.
It was a widely accepted " rule of thumb" in the days of only moulded hard rubber batteries that for every degree centigrade that the temperature drops below freezing point, batteries lose Five per cent efficiency. Minus five degrees robs a battery of a quarter of its power potential, 60 amp/hr down to 45 and pro-rata onwards, minus ten equals half power !.
I personally have revived batteries from motorway-stranded lorries so flat that the electrolyte froze ! (It had reverted to water !). FLAT is not always FAULTY ! But there again, you can recharge a flat one but can't re-incarnate the dead !
In an emergency to get started in very cold spells you might consider taking the battery indoors for a warm ! Standing a cold battery in a bowl of warm and then progressively warmer water works wonders. I would not, however, recommend standing your battery on the AGA nor in front of your log fire - A spell in hot water within an inch of the lid or deck and an occasional agitation enabling thorough warming of the acid works wonders !
Hope my contribution is of some help . John aka Jollychuffy

Jollychuffy wrote:

Mike, should it not have a strap over fixing?

These do not have a slot at each end for the spring pull-down clamps.

Rattletrap wrote:

You may well be right Mike.But i wouldn't go on the Bob Wilson book,packed with mistakes.

GKL 7 wrote:

This is all very interesting, but lets get the thread back on track.

But before we do, while on the subject of fuel, I'd like to ask harveypj why on the log book for my Routemaster bus, is the fuel (diesel) descibed as 'heavy oil'. What makes diesel work different from petrol :?

Rattletrap wrote: