Guys, i need help before this does my head in.....
Background to the situation, MT was my dads car, however now that he's no longer with us, it falls upon me to care for the old girl, many years ago dad bolted a ford dynamo to the side of the block, abouve the distributor, this clearly did away with the need to keep the old dynamo in good order.
Now, last year we spent a good sum of money rebuilding an entire engine, right down to distributor carb the lot.... obviously including an original Dynamo... the ford dynamo only had one wire connection to it, the 'shunt' off the old dynamo had been disconnected fro F! on the switch, and a link from the 'only
dynamo wire was placed into f1 instead...... this sytem worked well for many years, however as you can imagine, having had a dynamo rebuilt, i really need to get the wiring sorted so it charges ok again....
I have put both wires back onto their original places on the switch, and when running, the cutout box does nothing, if i hold the conectors together, and slightly rev the engine, it shows a healthy discharge...................
How can i re-test the dynao to ensure it's giving a charge, how can i test the cut-out box....... answers please in what i call plain english, i'm only a simple boy...LOL!!!
Many thanks in advance...!!
ps, not that it should make any difference, but the car is 1929, but we now have a fat dynamo in it.....
Cheers.
Charging help.................
Moderators: Ian Grace, Will Grace
Re: Charging help.................
It does not sound like it is charging at all, with the engine running and the cut out closed manually you should see a charge with the engine turning faster than approx 1100 rpm.
In my experience the only real way to test it would be to remove the dynamo, not easy on a ohc Minor! Then you can check the field windings and the armature with a test meter.
However a bulb attached between the heavier dynamo wire and earth should light up with the engine running. This shows the dynao is producing something. If this works then check this still happens at the cut out which will prove the wire between the two ok. Try this as a first step.
If the resister for high/low charge is burn't out the dynamo just goes onto high charge so that is nothing to worry about at this stage.
Hope this helps, step one at least!
Cheers
Jeremy
In my experience the only real way to test it would be to remove the dynamo, not easy on a ohc Minor! Then you can check the field windings and the armature with a test meter.
However a bulb attached between the heavier dynamo wire and earth should light up with the engine running. This shows the dynao is producing something. If this works then check this still happens at the cut out which will prove the wire between the two ok. Try this as a first step.
If the resister for high/low charge is burn't out the dynamo just goes onto high charge so that is nothing to worry about at this stage.
Hope this helps, step one at least!
Cheers
Jeremy
Re: Charging help.................
Have you checked that the frame of the the cut out is well and truly earthed to the chassis. Originally it relied on the fixing bolts, it is best to make a wire connection. If that fails you should check that the two cut out coils are intact.
Re: Charging help.................
Well, i'm now thinking that i've managed to do something to the dynamo.... went out there this eve, started it up, and witha simple test light there seems to be no output from the dynamo at-all....Mmmmmm, so, i'm guessing the best way to remove the dynamo is to get the engine to tdc on no1, then remove the dynamo and not move the engine at-all........ i have to remove the oil drain pipe first, as its an early one, and is very tight on the dynamo.... is the drain pipe on big dynamo engines different........??? i can't remove the band off the dynamo with the pipe in place... it's too tight...
Any ideas....
Any ideas....
Re: Charging help.................
Ronald,
OK - to get the dynamo out.
Undo the flex coupling bolts and try to end up with the the vertical drive fork in the head aligned left/right and the dynamo fork fore/aft - not for any timing reason at this point, but just so that the dynamo will come out, which is a always a real 3D puzzle on any OHC engine.
When you come to refit the dynamo, remove the cam cover and revolve the engine gently on the handle until you get nos. 1 and 2 cam lobes to form a symmetrical 'V'. The fork on the vertical drive should now be left/right again. Now you can fiddle the dynamo back in with its fork fore/aft and wriggle the flex coupling back in and fit the bolts. You'll have to rotate everything to get at all the bolts, but if you can at least get two in, everything should revolve together and you won't lose timing.
(The 'V' formed by the 1 and 2 lobes will coincide with no. 1 cylinder TDC - but check that the rotor is pointing to no. 1 plug lead - there are two possibilities, 'cos it's a 4-stroke engine - so watch out for Sod's Law here.)
As for the pipes, I think they are the same on all Minor engines.
One tip - while the dynamo is out, cut screwdriver slots in the four base securing bolts - you'll find it difficult to do the up tight with a screwdriver (particularly the rear ones), but near impossible with a regular spanner, and there isn't room for a socket. These engines were all originally assembled with box spanners.
One of the VMR Magazines had a comprehensive article on dynamos, but I don't seem to have posted it in the Members' Area yet. I'll try to do that tonight. It will walk you through testing the dynamo, and you might want to take a look at that before taking the dynamo out.
Another tip on pipes. If you have your head off at any point, replace the two studs under the front/right of the head which take the front drain pipe and replace them with bolts - that way, you will be able to remove this pipe with the head in situ if needed.
OK - to get the dynamo out.
Undo the flex coupling bolts and try to end up with the the vertical drive fork in the head aligned left/right and the dynamo fork fore/aft - not for any timing reason at this point, but just so that the dynamo will come out, which is a always a real 3D puzzle on any OHC engine.
When you come to refit the dynamo, remove the cam cover and revolve the engine gently on the handle until you get nos. 1 and 2 cam lobes to form a symmetrical 'V'. The fork on the vertical drive should now be left/right again. Now you can fiddle the dynamo back in with its fork fore/aft and wriggle the flex coupling back in and fit the bolts. You'll have to rotate everything to get at all the bolts, but if you can at least get two in, everything should revolve together and you won't lose timing.
(The 'V' formed by the 1 and 2 lobes will coincide with no. 1 cylinder TDC - but check that the rotor is pointing to no. 1 plug lead - there are two possibilities, 'cos it's a 4-stroke engine - so watch out for Sod's Law here.)
As for the pipes, I think they are the same on all Minor engines.
One tip - while the dynamo is out, cut screwdriver slots in the four base securing bolts - you'll find it difficult to do the up tight with a screwdriver (particularly the rear ones), but near impossible with a regular spanner, and there isn't room for a socket. These engines were all originally assembled with box spanners.
One of the VMR Magazines had a comprehensive article on dynamos, but I don't seem to have posted it in the Members' Area yet. I'll try to do that tonight. It will walk you through testing the dynamo, and you might want to take a look at that before taking the dynamo out.
Another tip on pipes. If you have your head off at any point, replace the two studs under the front/right of the head which take the front drain pipe and replace them with bolts - that way, you will be able to remove this pipe with the head in situ if needed.
Re: Charging help.................
Many thanks ian, i'd be a little dissapointed if i have done something to the dynamo, esp after having had everthing rebuilt.... but, as i said to Simon on the phone the other day, these engines are a mystery to me, give me an A series and i'll rebuild it with my eyes shut..LOL!!
I'll keep an eye out for the technical article..
Ps...... a reminder of the passwards etc for the members area would be of use... a PM will suffice...LOL!!
Thanks.
I'll keep an eye out for the technical article..
Ps...... a reminder of the passwards etc for the members area would be of use... a PM will suffice...LOL!!
Thanks.
Re: Charging help.................
Sent!Ronald wrote: Ps...... a reminder of the passwards etc for the members area would be of use... a PM will suffice...LOL!!
Thanks.
Ian
Re: Charging help.................
Ronald and all,
Just put M 127 Dynamo Electrickery in the Members' Area as a pdf, and also M 128 Dynamo Electrickery Postscript, under Technical Topics.
They should help.
Ian
Just put M 127 Dynamo Electrickery in the Members' Area as a pdf, and also M 128 Dynamo Electrickery Postscript, under Technical Topics.
They should help.
Ian
Re: Charging help.................
Well, another month has passed and i've still not got round to even looking at the minor.....
Just in case i need to think about replacing the cynamo, i have heard stories about alternators being available in the original dynamo casing, whats the score with this sort of thing, and where might they be available...... i've scoured the net and can find nothing...
Like i say, thats 'if' it can't be fixed, it'd be nice not to have to worry about lack of charhing ever again...LOL!!
Ronald.
Just in case i need to think about replacing the cynamo, i have heard stories about alternators being available in the original dynamo casing, whats the score with this sort of thing, and where might they be available...... i've scoured the net and can find nothing...
Like i say, thats 'if' it can't be fixed, it'd be nice not to have to worry about lack of charhing ever again...LOL!!
Ronald.
Re: Charging help.................
Hi Ronald,
This sounds like a mod the MG boys may be flirting with, but wouldn't be my cup of tea.
Can I suggest you get in tough with Dave Cooksey, who isn't that far from you now, and get him to take a look at it?
Ian
This sounds like a mod the MG boys may be flirting with, but wouldn't be my cup of tea.
Can I suggest you get in tough with Dave Cooksey, who isn't that far from you now, and get him to take a look at it?
Ian
Re: Charging help.................
Classic & Vintage Dynamos, attend Beaulieu with off the shelf exchange units of all types 
and do refurbs plus remanufacture and conversions of the sort you're looking for where the output is controlled by modern internals... Don't ask me, I also struggle with the blue stuff!
and do refurbs plus remanufacture and conversions of the sort you're looking for where the output is controlled by modern internals... Don't ask me, I also struggle with the blue stuff!if it's got wheels or chips - it'll cost you dear
Re: Charging help.................
Well, now back from my hols, and alledgedly refreshed, i have now removed the dynamo, had to remove the oild return pipe first though, and have removed the bottem gear, and slid the outer casing half off, and i can't 'see' anything wrong with it, i'm not good with these things, so will first up contact the guy that did the engine for us, and if that fails, then i may well buy a new unit from http://classicandvintagedynamos.com/dynamos.html they appear to have small bodied dynamos in their main picture... and it says, 'off the shelf'.... we'll see eh......
Re: Charging help.................
Dynamo out and in pieces, ish, tested the comutator, and all seems ok, tested the field windings, and i have continuity between the two wires, which aopparently i shouldn't have, i have sprayed loads of brake cleaner in it, but suspect somehow something has gone amiss....... have yet to get hold of engine man, but really want to start using the car SOON!!!
Re: Charging help.................
PS...... can someone please cofirm or otherwsie wether an early dynamo will fit in place of a late (fat) one......... is the nost casting on the block the same..???? ie, bolt spacing etc.......
To save anyone answering, i found out they're not compatible...... damn"!
To save anyone answering, i found out they're not compatible...... damn"!
Re: Charging help.................
You can fit a late/fat dynamo in front of an early block - even without the concave front face of the block - it is tight but it does fit fine. However, your dynamo needs to correspond to the correct base housing because of the bolt spacing.