Clock wise - counter Clockwise.

Hi Paul,

I found that reversing the exhaust and carburettor, and tinkering with the timing on an old Lister D would reverse its running direction. Although I seem to recall the D runs clockwise when looking at the flywheel in standard mode, so the Wolseley is probably similar.

With regard to alternators, there is no preferance as to direction of rotation as most units produce an AC output from the stator which is then rectified to provide a DC output for the battery.

Two things immediately spring to mind, 1; are you providing a DC supply to the alternator to excite it, because a battery must be connected at all times, and 2; what speed are you turning the alternator at?

Drives from most car engines cause an alternator to rotate at about

3000 rev/min or more at 'tickover', with a normal output being reached at anything between 10 and 20000 alternator revs. At this point a Lucas 40 amp alternator will be absorbing something in the region of 5 to 8 bhp from the engine at full current load, so you need a fairly high output engine able to rev to 3 to 4K revs with about a 4:1 step up through the belt drive, bit noisy on the field.

On the Dynamo note, again most have no particular direction of rotation, BUT, some do have a small brush offset that will require a specific direction which is usually stamped on the case. Output can be reversed if its 'sucking' instead of 'blowing' by repolarising the field once the circuit has been built.

An added bonus of using a dynamo is that it can be wired in such a way as to make it act as a motor to start the engine then switch over to generator.

I have been using an old Mini dynamo coupled to a BSA lawnmower engine for years to provide starting power for dead cars, mowers etc on a farm.

Hope this is of interest

John

I recall from my British Bike days that all you needed to do to reverse the polarity of a dynamo was to swap the field and brush leads over side for side. I ought to say that fifties Joe Lucas bike dynamos have no brush offset. Sturdy bits of kit, automotive stuff. Think where they work ...........

I planned to build a four speed winch once using a Triumph motorcycle gearbox and a Diesel starter motor. Never got it built, but the idea was sound.

Regards,

Kim Siddorn.

"He who is tired of bacon is tired of life"

King George III

I was looking amongst my Useful Spares for an old magneto for the ST P3 I'm attaching to my open framed dynamo. I came across a just post First War Bosch open magnet mag with a bloody great spark still - just the thing.

Of course, it is the wrong rotation - would be wouldn't it? - but it occurs to me that all I need to do is to retime the engine on the other side of TDC and reverse the engine's rotation to suit the magneto. The dynamo will not care which way it's going, especially as it has a movable brush ring.

Or have I missed something ?

Regards,

Kim Siddorn.

"He who is tired of bacon is tired of life"

King George III

Check sealing of governor case, if has an oil return scroll then you'll be bailing out! otherwise should be no problem. You could always reverse rotation of mag though, can usually be done by grinding a new retaining slot on the outside of the cam ring to reposition same such that points open at max rate of flux change in the required direction

Two strokes will run in either direction, once had old Francis Barnett start in reverse, timing was out.

Four strokes??? Wouldn't the cam shaft be rotating in the wrong direction? Lobes are ground slow rise fast fall to alter speed of valves opening? If reversed rotation this will be altered?

Lionel

Am I right in thinking that Lister D's have only one cam lobe and angled rockers. Bear in mind that - unusually for it's age and application - its an OHV engine.

Regards,

Kim Siddorn.

Yup, one cam and two angled followers.

Bamfords were OHV on the verticals, the Lister X was also OHV and that was really early on.

I shan't bore you with a list of early OHV engines, but they weren't as rare as you might imagine.

Kind regards,

Peter

Peter Forbes Prepair Ltd Luton, UK email: snipped-for-privacy@easynet.co.uk home: snipped-for-privacy@easynet.co.uk

"J K Siddorn" wrote (snip):-

Hardy and Padmore?

Hi. Alternators generally produce output in both directions of rotation. make sure you have the correct fan fitted though, Especially if you are going to be pulling a reasonable load from it. reverse rotation fans can be obtained from the alternator manufacturers. Make sure you have the field/ind terminal connected, Or you'll get no output. usually up to battery + through a small bulb or low value resistor is all that's needed on a modern alternator with built-in rectifier and voltage regulator.

Dynamo wiring is B for battery, usually a large terminal. F for field. often a smaller terminal. if you need to reverse the rotation or polarity of the dynamo remember to flash the field as required to give the dynamo the correct polarity residual magnetism.

the regulator box will vary slightly from manufacturer to manufacturer. but as well as the field and battery terminals you usually have an indicator terminal. I have some old lucas CAV regulator notes if you need any more help.

All The Best.

-- Tim Bluck