Dynamo help upgrade'

[Deleted]

I want to fit an alternator and have found a company that can fit one into the original dynamo case, but I am not sure how the power steering pump will fit or how it works now, any info would be welcome. Regards Ross

[Phil Nottingham]

It will not! That is the problem. Other cars used this arrangement and even same dynamo and some diesels used it to power the vac exhauster. Why not ask them as they must have come across this problem before.

Alternatively replace pump with modern electric version

[Deleted]

Thanks Phil, I will ring them tomorrow. Regards Ross

[stantondavies]

Do you really need to change? I have found the dynamo more than adequate once I'd got the control box set up right.

[Deleted]

Jul 28, 2011 22:54:53 GMT stantondavies said:

Do you really need to change? I have found the dynamo more than adequate once I'd got the control box set up right.

Only issue is it's my daily driver and I wanted to add dvd players for the kids as well as a hidden modern stereo and didn't thinks the dynamo would be up to it? I have contemplated fitting a very heavy duty battery, do you think that would do it?

[Phil Nottingham]

It will be borderline in winter - HD battery will help a little but it may run at a constantly undercharge will shorten its life

[rcoups]

I believe a Pajero alternater fits and has a pump on the back of it, dont take my word for it but research it online

[stantondavies]

Aug 1, 2011 16:07:08 GMT @rdm5555 said:

Jul 28, 2011 22:54:53 GMT stantondavies said:

Do you really need to change? I have found the dynamo more than adequate once I'd got the control box set up right.

Only issue is it's my daily driver and I wanted to add dvd players for the kids as well as a hidden modern stereo and didn't thinks the dynamo would be up to it? I have contemplated fitting a very heavy duty battery, do you think that would do it?

I'm encouraged that you are running the car as your daily driver, as do I. If my Rover isn't working then I'm walking. My take on your problem was why tinker when what you have already may prove perfectly adequate.
I have a heavy duty 70ah battery (standard is 57ah) which is about twelve years old now. The control box is set to 14.6V which keeps it topped up; I've not had any problem since altering the box which I did when the battery was fitted.
I don't run any media in the car but I do tow a caravan and use the car battery for power when on site.
So my advice would be: Carry on and see how you get on, if you have a big battery and the charging circuit is set right and you have problems, then "upgrade".

[Deleted]

Aug 1, 2011 17:51:26 GMT stantondavies said:

Aug 1, 2011 16:07:08 GMT @rdm5555 said:

Only issue is it's my daily driver and I wanted to add dvd players for the kids as well as a hidden modern stereo and didn't thinks the dynamo would be up to it? I have contemplated fitting a very heavy duty battery, do you think that would do it?

I'm encouraged that you are running the car as your daily driver, as do I. If my Rover isn't working then I'm walking. My take on your problem was why tinker when what you have already may prove perfectly adequate.
I have a heavy duty 70ah battery (standard is 57ah) which is about twelve years old now. The control box is set to 14.6V which keeps it topped up; I've not had any problem since altering the box which I did when the battery was fitted.
I don't run any media in the car but I do tow a caravan and use the car battery for power when on site.
So my advice would be: Carry on and see how you get on, if you have a big battery and the charging circuit is set right and you have problems, then "upgrade".

Thanks I think i will try the big battery route, I didn't know you could adjust the voltage regulator, that should work, I have also heard that jaguar ran the same dynamo with a geared pulley which span the dynamo faster when idling, so I will see if I can adapt it to fit. Regards Ross

[Deleted]

Aug 1, 2011 17:16:37 GMT rcoups said:

I believe a Pajero alternater fits and has a pump on the back of it, dont take my word for it but research it online

Thanks, I will do, it would save some hassle.

[Warwick]

Be careful readjusting the voltage regulator settings or you can damage the battery. A typical flooded cell lead-acid battery has a fully charged cell voltage of 2.1V. Therefore a 12V car battery containing 6 cells is fully charged at 12.6V. Once the regulator has recharged what is taken out during starting, it will automatically hold the battery at around 13.2V to 13.4V which is the "float" voltage and continue to supply the electrical demands of the vehicle.

If those demands at any time exceed the output of the dynamo or alternator, the excess is drawn from the battery and the regulator adjusts to recharge the battery until the float stage can be reached again.

Charging a 12V battery at 14.6V or thereabouts is known as an equilization charge and is not normally done by the car's own system. It is done by an external battery charger, and for the average car battery, is never done. Its purpose is to deliberately over-charge the battery to the point of gassing where water in the acid electrolyte breaks down into hydrogen and oxygen molecules which bubble out of the liquid and escape. This is done for a few hours under controlled conditions. It does several things. It removes lead sulphate which over time accumulates on the lead plates and reduces battery capacity (and life), it stirs up the electrolyte which can tend to stratify into layers of varying density (more water at the top), and it ensures that any under performing cell is pushed back up to full charge.

Because of the gassing, water is lost from each cell and so topping up is necessary when finished to ensure the plates remain covered. The caps should also be open to allow the gas to escape freely without pressurizing the case. An equalizing charge should never be given to a modern sealed low maintenance battery because the lost water cannot be replaced.

[Phil Nottingham]

The reason why dynamos run at a lower speed than alternators is that at high revs the armature windings will be damaged by centrifugal force especially if hot and soft through puttiing out max current to cope with high loads.

The high output 30A C45 is almost as good as the later 11AC and 17ACR alternators which do run at higher speed so are charging to some degree at idle and low speed which a dyno set will not.

I have managed with my 3 Litre Coupe in winter going to work with only occasional trickle charge overnight and this is in the dark both morning and night in all weathers in slow moving traffic

Why do you think a starting handle was provided - I have used mine on cold mornings when the battery was just too flat to fire up the coil and turn the starter.

Dynos do run at a higher nominal voltage than alternators ie 15.5v but if this is the mean voltage bulbs will quickly blacken and burn out

[Warwick]

But we mustn't confuse the voltage that the alternator or dynamo (generator) is able to produce and the voltage that the regulator applies to the battery.

Here are a couple of useful tips if you have a tired battery and have difficulty starting on a cold morning. The colder the battery, the slower the chemistry that takes place inside, so the slower the delivery of electricity. Operating the starter motor takes a lot of energy and this drops the battery voltage even further. This in turn reduces the voltage at the coil and so the spark is very weak while the starter is running. Rather than continuing to let the starter motor turn over the reluctant engine, sometimes it is best to crank the engine for awhile to ensure that fuel mixture has reached the cylinders, and then after that only crank in short bursts. Once the engine is spinning, switch off the starter (but not the ignition) and it may fire at that moment as full voltage is again restored to the coil and the spark improves.

If your car is always a troublesome starter, you can even take things a step further and run the coil from a different battery so you have full spark regardless off what the starter motor is doing. I've seen modifications where a couple of 6V lantern (dry cell) batteries are connected to the coil when the starter is operating and a relay switches the coil back to the main battery after starting.

Another trick if you have a tired battery AND a crank handle is to turn over the engine by hand a few times first with the choke out and the ignition off. This primes the cylinders with mixture so they are ready to fire when the starter motor is operated, thus saving the battery for the important bit.

This last method is often the best way to start a mower or other pull-start engine. Leave the ignition off. Set the choke. Pull the cord a few times, gently, to prime the cylinder with fuel. Then switch off the choke, turn on the ignition, set the throttle, and give one brisk pull on the cord. It will usually start and run smoothly without kicking back.

[enigmas]

Well put Dr Warwick. You always amaze me with your technical acumen...and all the above is a good reason to have the best quality Ignition leads that you can afford.

Now you need to look at the post on leads:

roverp5.proboards.com/index.cgi?board=Rover33&action=display&thread=5449&page=1

As an aside, I recently replaced most of the main ignition equipment on my P5 (plugs, rotor, distributor cap and leads...to a very high spec set) due to some 'hard starting of late (its been quite cold of late down under) I found one dead ignition lead (it didn't register on my multi-meter) so it was obviously open circuit.

It now starts instantly; prior to this, it was giving the battery quite a work out (lack of TLC) and I was considering replacing the battery...which now copes admirably.

Both the cap terminals and rotor button end had eroded considerably causing an undesirable larger than spec air gap.

Unfortunately these items don't last forever. Although the insulation may be ok the tolerances eventually end up way out, causing a high load on the ignition system and consequently the battery.

Less cranking means a stronger spark especially on a high comp LPG engine. Cold weather as Warwick has explained also reduces the efficiency of the battery.

[Warwick]

Thanks Vince. It only partly compensates for my general lack of knowledge of the P5. It's a shame I can't amaze you with the performance of my car.

[frans]

Hi,

i have read with interest this discussion to upgrade from DC Dynamo to AC Alternator. I have done this on my Morris Minor and it has been a big improvement in reliability. Now I am working on my P5 MK I and would like to fit an Alternator. Is there a solution available in the meantime to deal with pump for the power steering?

Any advice welcome!!

Frans

[enigmas]

Why not keep it as simple a conversion as possible Fran. Fit a modern alternator in place of the dynamo (as you did on your Morris), then get hold of a V8 power steering pump and fit it where space allows taking the drive off a piggy-back pulley. (ie., weld 2 pulleys together) It doesn't have to be driven off the crankshaft pulley.

[Phil Nottingham]

The Dyno-alternators are now available with P/s take-off.

[frans]

Phil,

thanks for the info! Do you have a source for the Alternator with p/s shaft?

Thanks
Frans

[Phil Nottingham]

www.powerlite-units.com/about-dynalites/

RAC023 would appear to be the one and you would need to change the polarity to -ve earth of course and the C42 is 8mm longer so a spacer will be needed.