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Alternator Conversion options and modification - relay ?


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Hello All, 

I am currently in the process of completing some optimizations. 

One of them is the modification of the charing system from generator to an alternator. The conversion and rewiring instructions are clear (attached) , just that the Dynator offered by Moss does not require a relays installation between the cable from light to switch. The instructions coming with the kit of Limora does. 

Any advice, if the relays is really required and if there is a difference between the Limora and Moss product ?

Moss PART NUMBER: PT10802P

Limora Part  491267 

Thanks

Oliver

Drehstromlichtmaschine (3).pdf PT10802P_instructions.pdf

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Im not a fan of those Dynators as they tend to suffer cooling problems which do shorten their life.

Stuart.

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An alternator generates more current so dissipates more power than a dynamo. They need a lot of cooling which is why they generally have very 'open' construction with lots of cooling slots. The cooling fan draws air from the rear of the alternator and through the body.

 Enclosing them in a sleeve to look like a dynamo compromises convective cooling and they must have a good cool airflow.  Maybe not too bad if they are located on the cooler side of an engine but putting one near the exhaust manifold, as on the Triumph four-pot, is asking for trouble I think.  Even a normal alternator is happiest in that position when it has thermal shielding. 

The Moss / Wosp dynator obviously has internals which drive the ignition lamp properly. The Limora one doesn't and needs the relay so that the lamp isn't lit all the time when the ignition is off. 

 

 

Edited by RobH
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Yes, the Dynator had a bad press for unreliability at one point.  It may well cook on a TR as it is next to the exhaust manifold and has little or no air flow through it.


Not sure why there is a relay in the circuit to energise a warning lamp.   Perhaps that is required on another type of car, or the Limora unit has incomplete internal control systems leaving the ignition warning light circuit energised even when the ignition is off.   

Below is the Unipart info I have always used on a TR.  it means the existing wiring is used and the control box can stay where it is,   No additional wiring is needed just a couple of cables joined.   This is with Lucas alternators of the ACR type.  Which are a struggle to fit easily on TR2-3 as adjustment is limited by the closeness of the bodywork      Electrically It works perfectly with my Nippon Denso unit on my TR3.   As sold as a kit by Racetorations    https://www.racetorations.co.uk/product/lightweight-40a-universal-alternator/

The usual reason people buy the Dynator is the period look compared to a modern alternator    

Unipart.pdf

Edited by BlueTR3A-5EKT
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Thanks all, very helpful input. 

I think I may just  (proactively) replace and/or overhaul my good ole generator and just convert to the narrow belt drive.

 

 

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Next question: any (negative )experience with new, reproduction Lucas C40 generators ? - Always reluctant to exchange original quality to reproduction....

(I would just get in a new part and have the old one overhauled one day by an expert)

Thanks

Oliver

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I am sold on the small Nippon Denso alternator conversion and would need a very compelling argument to go back to a dynamo.

Repro dynamos in my experience are unreliable.  I fitted one to The Moss TR3 after it failed in the Mojave desert one night and I had to drive another 100 miles without lights in convoy with a TR250 and 6.    That was fun!

Drove the car 500 miles after fitting an NEW dynamo  and the rear bearing seized in the dynamo, requiring a complete replacement.   With hind site I should have lubricated the NEW dynamo I fitted at Lake Havasu before driving the car back to Santa Barbara.   Hands up any one who thinks they need to do that to a new unit.     The replacement dynamo failed on a road run in Topanga Canyon one week or  some 500 miles later.   
So.   Poor quality new replacements from the far east.   In Europe we used to buy Indian manufactured new units and they were far more reliable.   

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Hello Oliver

                   I would go for a Nippon Denso one(just make sure it is a genuie one!)

I have had one on my little 1500 Spitfire for 7 years(33,000miles)

I fitted when I fitted Microsquit and ITB'S EFI as I needed more output as the pump runs all the time(Range Rover one fitted into the tank)

Plus it leaves more room on the Spitfire to get at No1 plug!

Roger

ps plus if you tour in Spain etc like us if it did fail you could get a new one easy as they fit to lots of garden type tractors!

Alternator Unit N/denso IR/IF 12v 40Amp | eBay

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Alternator Nippondenso IR/IF 12v 40Amp | FREE UK DELIVERY | Flexible Ways To Pay | M&P (mandp.co.uk)

not sure why links do not work (mysteries of Tinterweb?)

Roger

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Still very reluctant to change to a modern looking piece...

Can it be fitted to the original bracket without modification or would more tailoring be required ?

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To fit the. Nippon Denso unit you must use the fitting kit specified on the Racetorations site.

https://www.racetorations.co.uk/product/lightweight-40a-universal-alternator/

 

This is  because the alternator fixes in  a different position relative to >Front to back< so shorter mounting pedestal is required.   I have changed a standard TR item on my lathe   
If using Lucas ACR alternator the adjustment to the mounting pedestal is not required, but a spacer for the back mount is needed.   is. BUT the alternator gets very close to the inner wing and adjustment to tension the belt may be an issue.   

 

Edited by BlueTR3A-5EKT
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1 hour ago, Ian Vincent said:

As a cheaper alternative than the Racetorations kit, search for Kubota Denso 40 amp alternator on your browser.  There are plenty on offer at around £100.

Rgds Ian

The standard Kubota item requires an additional ignition controlled supply to get the thing to work.    The Racetorations item uses existing vehicle cables without any additional wires.

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53 minutes ago, BlueTR3A-5EKT said:

The standard Kubota item requires an additional ignition controlled supply to get the thing to work.    The Racetorations item uses existing vehicle cables without any additional wires.

I’m sure you are right Peter, it was a long time ago that I fitted my Kubota alternator and at the time it only cost £65 Inc postage, but I don’t recall any issues getting it to work and I’m pretty much a numpty with electrics. 
Rgds Ian

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If you want an alternator which appears somewhat old-fashioned, you could fit a 17ACR type, which is the unit fitted to the 1970 TR7 - this is what I fitted in 1993.

Now available for about £54 from ATP Electonics as LRA1-1/ACT16002 - essential to specify Lefthand (even though it will be mounted on the right of the engine).

Best to modify the bracket as described in the blurb for Revington's 058912.  Revington came up with this bracket in 1993 when first fitting the alternator to 4VC.

When I fitted this type of alternator back then, it was rated at 34 Amps, but it seems to have crept up nearer 45-50 Amps now - but 34 Amps is sufficient for any standard TR.

I described the fitting of the alternator in TR Action118 (November 1994) - can also be found in Section J4 of Technicalities.

Ian Cornish

Edited by ianc
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14 minutes ago, ianc said:

If you want an alternator which appears somewhat old-fashioned, you could fit a 17ACR type, which is the unit fitted to the 1970 TR7 - this is what I fitted in 1993.

Now available for about £54 from ATP Electonics as LRA1-1/ACT16002 - essential to specify Lefthand (even though it will be mounted on the right of the engine).

Best to modify the bracket as described in the blurb for Revington's 058912.  Revington came up with this bracket in 1993 when first fitting the alternator to 4VC.

When I fitted this type of alternator back then, it was rated at 34 Amps, but it seems to have crept up nearer 45-50 Amps now - but 34 Amps is sufficient for any standard TR.

I described the fitting of the alternator in TR Action118 (November 1994) - can also be found in Section J4 of Technicalities.

Ian Cornish

All well and good on a modern where the engine bay is wider than a sidescreen car.   The mount brackets on a Lucas alternator are not 180 degrees apart, as they are on a dynamo or Nippon Denso alternator. Plus the alternator is a good inch bigger in diameter.      The ACR alternator gets horribly close to the inner wing RH side when tensioning the fan belt, which is why the little Nippon Denso thing is so attractive.

The factory option alternator kit for TR4A included a different front engine plate and as you state different shaped mounting bracket.  The alternator offered was a 15 ac unit with external regulator.  
 

I'll get my anorak.

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37 minutes ago, BlueTR3A-5EKT said:

All well and good on a modern where the engine bay is wider than a sidescreen car.

Well here's an 18ACR fitted to my sidescreen car  - enough room I think.  It uses the dynamo mount with a rear spacer at the bottom but the top mounting bracket is home-made.  A slightly shorter belt allows it to be swung inwards away from the wing. 

altmt.jpg.51835083be25b14cf46f899a7be4bb27.jpg

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39 minutes ago, RobH said:

Well here's an 18ACR fitted to my sidescreen car  - enough room I think.  It uses the dynamo mount with a rear spacer at the bottom but the top mounting bracket is home-made.  A slightly shorter belt allows it to be swung inwards away from the wing. 

altmt.jpg.51835083be25b14cf46f899a7be4bb27.jpg

Yep that is precisely how we did it on Brother’s TR2.  The issue we had was finding a shorter wide type belt and being able to fit it without un hitching the lower mounting bolts.

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The belt I have used is a 17mm BX section type,  which are widely available in a variety of lengths. 

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I have run on 17ARC type for over 20 years but they do fail and I think its down to heat. As mentioned before they draw air in through the back cover right next to the manifold down pipes which is not good.

I talked to a local re builder of these units and he said they did make a fan that blew in from the front .......but after looking he hadn't got one! I toyed with he idea of making one or getting one scanned, reversed and then printed....in the end I fitted a Denso (knock-off) and I'm very happy.

As I see it on the 4 pot install these alternators start off at low speeds drawing air in from the back then, as road speed increases there must be a stall point before total confusing on airflow and then at higher road speeds possible flow from from front to back. All this comes crashing down when you stop/tickover and its back to sucking in super heated air again.

I ran my last alternator with no fan on at all to see what happened but chickened out in the end as it exposes three large induction holes a the front and as I use mine all year round I thought it would more likely fail due to water pressure!

 

 

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That’s me told then.  

I had forgotten the cooking alternator problem though.  
 

The alternator fitted initially was a Lucas  A127 from a Metro then a short bodied metal rear cased Delco unit from a NAS spec TR6 & V8 MGBGT.  Both chosen because I had them FOC in my parts bin.  In those days you could buy redundant car parts from BL main dealers at £100-£200 per ton.     We  fitted a heat shield to the bunch of bananas on brother’s TR2 back in the 1980’s  and also one to the starter motor to reduce the heat radiated to the electrical units.

 

Edited by BlueTR3A-5EKT
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