Lucas 25D for early series 3

Kevlcat · Jun 21, 2019

Hi all,

Getting on with my 72’ 2.25 petrol rebuild......fresh rebuilt engine went into chassis last week..... now I’m turning to the dizzy.....but am slightly confused (or maybe not?)

Early S3 had Lucas 25D dizzy. Mine is certainly a 25D but the stamped serial no is “41269 F”

On further investigation this serial no seems to point to a Morris Minor!!

Is my dizzy wrong?.....does it matter?

Thanks to all

tottot · Jun 21, 2019

Probably right. The Lucas 25 D was pretty much a standard fit for many British cars in the 50's to 70's.

Dippypud · Jun 21, 2019

tottot said:
Probably right. The Lucas 25 D was pretty much a standard fit for many British cars in the 50's to 70's.

Yeah, but fit leccy kit makes life much easier for not much money ...

https://www.demon-tweeks.com/uk/lumenition-distributor-ignition-fitting-kit-244516/

rob1miles · Jun 21, 2019

Things to watch out for are the advance range, the direction of the vaccuum and the full advanced revs (set by the A/R springs. Suspect Moggie and Series very simlar so it may work ok. Worst case you can swap the bits.

ExMil109 · Jun 21, 2019

The info I have (see http://www.starchak.ca/tech/pdfs/lucas.pdf) doesn't have detailed data on Series 3 distributors, but it does have some for Series 2A e.g. model 40944. If you compare the advance curves for 41269 and 40944, it looks like the 41269 has much less advance than the 40944.
So I suspect your dizzy will work, but you won't get maximum power and the engine might seem a bit flat.
In theory you can replace the springs/weights to get any advance curve you like, but it might be easier to just replace it, especially if it's a bit worn.
If you're not too bothered about originality, you could replace it with a 45D4 or a Ducellier, both of which are still available new (at a price!) but I'd avoid the £30 45D4 copies - they're likely worse than your Morris Minor dizzy...

Kevlcat · Jun 21, 2019

Thanks all for the responses.....

I am thinking along lines of either electronic ign or 45d so will see where it goes over next couple of weeks

Ta

rob1miles · Jun 24, 2019

If you do go electronic look to get rid of the mech advance and retard and go electronic for the adcance curve. A lot of poor running comes from worn weights and springs and the whole lot is a bad compromise, its not an "advance curve", more a short step then its stuck on full advance.

Lucas 25D for early series 3

Kevlcat

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tottot

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Dippypud

Never Knowingly Understood

rob1miles

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ExMil109

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Kevlcat

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rob1miles

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