Daft Question.

[Highlander]

I am glad that Halbe now know how well a 1932 sv 2 seater goes. I took Molly to the golf club BBQ last night i the 2 seater of course, I was the hotest night of the year down here in the South of England and when we left at about 11.30pm we could not have wished for a better night. Here is the question - on night like this, moon shining, air cool, why do vintage cars run so much better? Is it anything to do with the claret? Happy minoring, Highlander.

[Ronald]

Sounds like the ideal evening for a drive..!!

In answer to your question, cooler air helps a lot, and also slight dampness aswell...... if you're ever brave eough to use the car in the winter you'll find the same thing happens..... colder air is denser, therefore there's more power produced to there being a bigger bang...... thats the idiots reaonsing anyway, i don;t 'do' science...!!

[DF9053]

It is also to do with the petrol, modern pertols vapourise at lower temperatures, in our cars this causes a shortage of petrol reaching the engine in hot weather.

If you add paraffin in the ratio of 1 part to 10 of petrol this will raise the vapourisation temperature and also lower the octain rating to a level more suited to the Minor and other prewar engines. I have not tried this yet, but DF suffers badly from vapourisation so once I have found a source of paraffin or heating oil/kerosene/air craft fuel (which is all the same stuff) I will give it a go!

There is an intersting dialogue on this in the Octagon Car Club newsletter as this affects all pre-1956 MG's

Cheers
Jeremy

[chris lambert]

As for vapourisation, my saloon suffered badly from this as the fuel line outlet on the firewall exited immediatly behind the exhaust manifold. After I moved the hole a couple of inches to the left my fuel vapourisation problems vanished!
Chris

[Ian Grace]

And water vapour definitely helps. I can't recall the precise mechanism now, but I do know that when I was working on Shackletons, they had a water/met injector system to primarily ass a small proportion of water to the fuel vapour mix to improve performance of the RR Griffon engines. I have always found that my Minors give 10 to 15% more oomph on cool, damp evenings - SV and OHC equally.

[cammy]

I don't know whether this is true or not but someone once told me that the damp, being water, h2o, means their is more oxygen to aid combustion, ???????????

All I know is NG has had too much damp in the wrong places in the past!

[Ian Grace]

Found online - Water Injection or Water Methanol Injection, is a process by which a mixture or water and Methanol are injected into the fuel/air mixture on the way to the combustion chamber. Water/Methanol Injection provides "Chemical Intercooling" inside the cylinder. By injecting water and methanol in a finely atomized spray, the water is able to evaporate under the high temps of a firing cylinder, and when the water evaporates, it takes heat with it. The methanol also has a cooling and octane boosting effect as it burns.

And - In a piston engine, the initial injection of water cools the fuel-air mixture somewhat, which increases its density and hence the amount of mixture that enters the cylinder. But the greater effect comes later during combustion when the water takes in significant amounts of heat energy as it converts from liquid to gas (steam). This increases piston pressure (torque), reduces peak temperature and resultant NOx formation, and reduces the amount of heat energy absorbed into the cylinder walls

So cool, damp air is good.

[Highlander]

Thank you all for your comments. Went back to the club tonight and tried the sauvignon - just as good! However on unlit, counrty roads at speed my light s are hopeless., I would go as far as being unsafe. I have driven over these roads for over 50 years and know them well, all the bends etc . Can anything be done? I am still 6 volt. Reflectors not too bad. Are these modern bulbs any good? On well lit roads I have no problem but with grandchildren one must take care. Good night all, time for a Scotch. Highlander.

[Simon]

I am using 25/25 watt 6v bulbs in my Jensen Minor. you may have to modify the reflectors to take double contact bulb holders. As yours is a 1933 model it should already have twin filament bulb holders. You will probably find it advantageous to add an earth return wire from each reflector back to a good clean point on the chassis/(engine) to reduce the voltage drop to a minimum. If you have trouble starting it is also a good idea to run a heavy duty cable from the battery negative to one starter motor body fixing bolt. I will post details of bulb supplier later.

Simon

[Ian Grace]

I concur with Simon's comments regarding good earths. 6 volt systems are more sensitive to resistance in the circuit than 12 volt systems. I always run earth wires back from my lamp holders to solid points on the chassis rather than relying on the metal contact between lamps and wings, and wings to chassis. This is a common problem on newly-restored problems, where everything is painted and direct metal contact is the exception rather than the rule.

[Ken Martin]

Alister
It is worth investigating the use and availabliity of suitable halogen bulbs as Trevor Wilkinson impressed us all with his 34 Minor headlights - in daylight - at the VMR rally when excersing his car on Thorpe Abbis runway. He has been using them for a long time.
Ken

[Highlander]

Re my lights. Lovely day today so took 10 minutes to look into my headlamps. A little history - my 33 minor was updated by previous owner, Mr. Curtis, to 1934 spec and behond, i.e. hydrolic brakes, brake lights.etc. I have seperate side lights on the wings. On opening the headlights (single screw on the rim at the bottom) the rim and reflector came away in one piece - looked in very good (new)condition. The 6 volt bulb looked modern - not a large round bulb as I expected but a 'long' bulb. The three conection from the back were all in lst class condition and all conections correctly conected. The earth wire was conected to the a modern e lamp shell but very well done. On the reflector was a small hole with cycle type bulb which was not conected, i think these reflectors must be a modern replacement. I shall go out tonight and have a really good try to see in the real dark. Thanks for all your comments. Highlander.

[Trevor Wilkinson]

I am using 25/25w Halogen bulbs. It wasn't just a case of putting in the bulbs, this created a wide spread of light but not much use for driving. I had to make extensions for the bulb holders to get the bulbs to focal point of the reflector, and create a half decent beam.

[Ronald]

When i get round to re-wiring MT, i shall run all the earths back to the battery, can;t see the point in doing it any other way when the car is so small.....lol

[Simon]

Sorry I forgot to say that my bulbs were Halogen. Word of warning - Do not touch the glass part of the bulb with your fingers, if you do remove all grease with methalated spirits. Grease on the glass may cause the glass to shatter.