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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - Stealth Alternator

I have mentioned on this site previously that I had converted my TF to a alternator using a very expensive unit (£400) This has failed three times and the supplier has now offered me my money back. The reason I opted for the expensive one was it had a tacho take off at the rear. I now see that the Stealth Dynamator has a rear take off and is priced at a very reasonable £130.95. A local alternator repair firm believe the problem with dynamo lookalike alternators is cooling. The casing on regular alternators is littered with air slots and they have a large fan. Shoe horning an alternator into a dynamo case leads to overheating and burnt diodes. Solid state dynamo regulators are also expensive (£188) and if I reverted to a dynamo I would only get about 15A of current. Has anyone experience of the Stealth unit.


Jan T
J Targosz

The Lucas dynamos are rated at 17 or 19 amps, depending on the model, at 2000 RPM (engine). They will put out more, of course, at higher speeds. They are adequate for a stock car, even if you have modern lights that take a bit more current. If you add electrical equipment that draws more current, you'd have to reassess the situation.

An improved, electronic voltage regulator is worthwhile, as it potentially will keep the voltage more constant and contribute to improved battery life. Your £188 price sounds pretty steep to me; I have an electronic regulator on my '67 Porsche and it only cost $35 US.

The claim that look-alike alternators have poor cooling may be valid, but probably overstated. After all, they sell the things, they get used, and not all are returned.

If I were in your position, I think I'd keep the dynamo and look for a sensibly priced electronic regulator.
S Maas

A few years ago, Barney Gaylord (MGAguru) and I did some testing around the idea of using the VW solid state regulator in our cars (and MGAs). The generators are a different design and the regulator is incompatible. I suspect that the Porsche one is similar to the VW one. Bud
Bud Krueger

Jan T
I have the same interest in these inexpensive alternators and have searched for some comments on them, but found nothing yet. Very disappointed to hear of the problems that you have had so far with the more expensive version. My fear with the cheaper one (I assume Far East manufacture) was that the bearings and general electrical integrity might not be up to snuff, but that seems to be the least of the issues. If underbonnet temps are important then one might assume both versions to be afflicted but not necessarily so. On balance I think I will take a punt for only £130. Just as a matter of interest, are you running a mechanical fan or an electric fan? Also if electric, the temp setting. It just crossed my mind that it coukd make a difference. I hope Dave Dubois reads this because he didn't seem to believe me when I said these new lower cost alternators also came in a version with the mechanical tacho take-off,
Dave H
Dave Hill

Dave H - I did find the site for the lower cost alternators (forgot to get back to you on that). At present I am considering converting our TD to negative ground to keep the cost of the alternator down. That said, I have gotten a new regulator to replace the electronic one that failed (produced by a local gentleman who passed away a couple of years ago) and the charging system is back up and operating good at the moment. I am now in a bit of a quandary - change over to alternator that may or may not be reliable or stick with the dynamo and mechanical (relays vs electronic) regulator That has been quite reliable in the 30 years we have owned the TD (a car that is driven on a daily basis (except when there is salt on the road). Cheers - Dave
D W DuBois

If you go to the AccuSpark web site you will see the tacho drive alternator for sale for £134. I spoke to the Dynamo Conversion Company and their electronic dynamo controller is £180. I am just concerned about the quality and reliability of such an inexpensive alternator. AccuSpark tell me they have sold over 1000 units without problems.


Jan T
J Targosz

Well the good news is that the net is not awash with negative comments, and I'm sure it woukd be if there were lots of issues. I too have gone for negative earth, there seem to be only good reasons for doing so. I am running higher output headlight bulbs with relays a thermostatic fan with relay and a modern high output heater, plus I want to be able to use GPS. The higher output of an alternator makes sense for me. Or at least it will when I finish off in a few weeks. I will probably buy one at the mg spares Day at Stoneleigh. I'll report findings here. Dave, I would like to think that my car will get as much use as yours, but in our climate I suspect not!
Dave H
Dave Hill

Dave H - "I would like to think that my car will get as much use as yours, but in our climate I suspect not!"

We live in the Puget Sound area of Washington State, If you look at the weather pattern for this area, you will see a string of storms marching across the Pacific, right into Oregon and Washington State. Yesterday, we got a bit over 2" of rain in our location, with at least another 5 days of rain in the forecast. Our weather is pretty much the same as what you get in England. We have a weather proof garage where the TD and MGB can dry out after having been soaked from driving in the rain. As long as the cars has a place where it can dry overnight, they are fine. What about water getting into crevices or other places that get wet? We drove our TD for 5 or 6 years before I restored it. It even set out under a dinning fly one winter while I was working on another car, when I tore the TD down to restore it, there was only one or two places that had any serious rust and even that was not bad. Drive the car and let it dry over night and it will be fine - just don't drive it when there is salt on the road (I let a weeks worth of rain fall before I take the cars on the road after a snow fall. One nice thing about these cars - they were all preshrunk in the factory - they don't get any smaller when they get wet.
Cheers - Dave
D W DuBois

Hi Dave Hill,

I have just noted the Stealth doesn't have a pulley. I wonder if the old dynamo one is a straight fit? Also not sure if AccuSpark, who sell the Stealth, will be at Stoneleigh.

Cheers

Jan


J Targosz

I now have two seasons on a Race Mettled alternator with tacho drive on the rear end. No issues so far, I run H4 halogen lights up front, a heater, electric radiator fan and an mp3 amplifier.

regards

Jan
Jan Emil Kristoffersen

Jan T
They are listed on the MG Show website as an exhibitor with BB Classics. I think the pulley is a straight fit, but in any case can't see its big deal to fix if not.
Dave DuBois
I take your point on Washington, I assumed it was DC! Mind you, we live in a country that's on a similar latitude to Hudson Bay! I still think you're a hero for driving mostly year round. This is my first T but not my first MG or classic. I did run a TR3 but nothing would have got me out in that in winter.
Dave H

Dave Hill

Jan E K
Is that a regular alternator? With all the ventilation holes and all? If so, it probably reinforces the point about less than ideal cooling on these alternators disguised to look like dynamos.
Dave H
Dave Hill

Dave;

this is a C39 Lucas look-a-like. No vent holes. So no really efficient cooling, but so far it works.

regards,

Jan
Jan Emil Kristoffersen

That's very interesting. I looked at the Racemettle website and see that they have lots of interesting things. I also see that they are the same oufit as Racestorations, that I bought a few things from back in my TR days. They give the impression that they manufacture their own alternators, or at least make the metal case for them. Pricing looks similar to Dynalite. I'll try the cheaper type first, but its certainly a fall-back.
Dave H
Dave Hill

The problem with my WOSP unit is certainly a cooling issue. Last night after a test run the charging light came on and the ammeter showed a discharge. This morning everything was OK! After another run the charging stopped. Just been out again, engine bay cold, and the alternator works once more.


Jan T
J Targosz

In last months Octagon Bulletin reference was made to a POSTIVE EARTH dynamo/alternator as shown at last years NEC BIRMINGHAM show. Apparently price at only a little above a dynamo ( it was £120) a NEGATIVE EARTH version is due during this month.Awaiting a report from the purchaser of the show one.It comes with the gearbox facility connection.I've put my name down for one.
JK Mazgaj

I'm glad someone posted this, I am definitely looking for an inexpensive upgrade as I want to add an electric fan to the car. I recall a discussion that suggested that anyone considering this should look at potential wiring issues due to the increased amperage, including possible damage to the ammeter (pegging out at higher load). I'll have to refresh my memory on that.
Geoffrey M Baker

I think the Lucas generator fitted to the Mark I Sprite (bug eye) had a slightly higher output than the original one on a T Series car and the bug eye one does have a tach drive feature. As for me, I reduced the lighting load by changing over to LEDs on the tail lamps and front side lamps. It made a difference judging by the ammeter.
John Quilter (TD8986)

If I remember correctly, the midget dynamo put out up to 22 amps, where as the dynamo on the 53 TD and the TF puts out 19 amps, not a tremendous difference. Cheers - Dave
D W DuBois

I have now decided that if I am to fit an alternator why bother to disguise it. I attach a photo of one from a Renault Clio which I have converted to tacho drive and a V pulley. It is the same diameter as the old dynamo but shorter. I have spoken to several classic car charging system specialists and all say that earlier alternator dynamo lookalikes were based on a Denso unit which was normally fitted to a sit on lawnmower. When this was assembled into a dynamo case the cooling slots were covered hence the overheating problems. I am told the latest version have been built from scratch so cooling could be OK. The Renault version which I have converted is covered with ventilation slots and has fans at both ends of the rotor. The finned heat sinks for the electronics wouldn't be out of place in a nuclear power station.

Jan T


J Targosz

Interesting, and looks a good solution. I guess that they could have got away with just putting cooling slots on the underside of those in a dynamo case, where it wouldn't be seen, but would have added more cost.
Dave H
Dave Hill

This thread was discussed between 06/02/2015 and 11/02/2015

MG TD TF 1500 index

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