Lucas 25D rotor arm in a 44D4 Sprint distributor

[GrahamFountain]

Does anyone have any experience of running a Dolomite Sprint with a Lucas 25D rotor arm, I'm thinking red, in the standard 44D4 distributor with standard cover/cap. I've tried it, and it works driving round the block a couple of times, but I worry there may be issues to be found. And as a great believer in Sod's law, I expect to find them when and how they cause the most disruption.

I'm asking because I'm considering electronic ignition as a solution to my continuing battle to find a condenser that will last more then 50 miles. And many of the more cost effective electronic ignitions available don't fit with the 44D's rotor arm. I know the usual solution is use the 45D rotor arm and the 45D4 side entry cap, but I want to stay with the 44D4 cap if at all possible.

Graham

[Carl]

Lucas Sport coil, Magnecor leads, Newtronic/Pirahna ignition, and a red 25D4 rotor arm. No ignition issues in 10yrs/~35,000 miles. Go for it !

[Carledo]

The accepted wisdom is that the 25/45D4 rotor is too tall and will eventually foul/destroy the carbon brush and its housing in the stock 44D4 cap.

Obviously, from Carl's post this is not a universal constant! (production tolerances at work again?)

I've kinda given up on fitting EI to 44D4s having removed more than a handful of failed Magnetronics. I've not spoken to him specifically on the subject, but it appears that SimonBBC withdrew his 44D4 kit BECAUSE the failure rate was too high for comfort. I have one, NOS still boxed, it didn't work at all the one time I tried it in a Sprint. I THINK it was one of his, I didn't buy it, may have been a Britpart, they are almost identical visually. But it didn't come in his trademark green and clear plastic "accuspark" labeled container, just a plain grey cardboard box. But I believe it had been kicking around for years.

Which only really leaves the Lumenition Optronic (which I have a lot of respect for, but is a bit expensive for me to experiment with at the best part of £200 a kit) and the 123 dizzy, the only example of which I have seen fitted, is in Mahesh's Sprint which we took on the RBRR in 2018. It behaved faultlessly and the car drove well and was extremely good on fuel, averaging 43+mpg over 2166 gruelling miles. But one swallow doesn't make a summer and I KNOW for a fact that Mahesh jumped through many complex and expensive hoops to make it work.

I have a (customer) Sprint with me presently that I have built a distributor up for, it will run points initially, but has the Ambassador cap and red 25/45D4 rotor ready to fit an Accuspark 45D4 kit to, once i'm happy with how it runs on points. But it will be several weeks before it is even running at all, the engine and box are still on the floor and I have work to do in the engine bay before it goes in.

Steve

PS, I think if I actually owned a Sprint powered Sprint, i'd look into the crank sensor and EDIS type setup (along with EFi) as a long term solution, fix it once and fix it right!

[cleverusername]

Just use a side entry ambassador cap and you will have no issues. I see no reason to keep the stock cap.

[GrahamFountain]

Just use a side entry ambassador cap and you will have no issues. I see no reason to keep the stock cap.

I have spares.
Graham

[GrahamFountain]

I have one, NOS still boxed, it didn't work at all the one time I tried it in a Sprint.

Oddly enough, I had that with one I got from somewhere. Also, I went out for a bit today and had to keep kicking myself for thinking how well it went.

Personally, I hope the Distributor Doctor's condenser solves the problem. That will mean to me that the modern ones I got are rubbish and there's no other fault to look for. If it dies then there's a problem I might mask with a leccy unit. But will that just postpone another failure like the coil.

Thing is I've tried everything I can think of apart from going back to the old spark plugs - this all started when I did plugs, points, and condenser all at once. I have tried alternative points, dizzy, cap, leads, and a range of condensers. I've measured the voltage at the top of the coil with the points closed cold (5.8V @ 12V battery) and hot (6.5 @ 13V), both of which seem fine. The only other related issue I know of is there's no 12V boost from the starter solenoid. But I no more see the connection (pun) with that than to the plugs.

If it lasts a week, I'll be feeling a bit more confident. But right now, every shopping trip feels like a gambol.

Graham

[Carledo]

Just use a side entry ambassador cap and you will have no issues. I see no reason to keep the stock cap.

I have spares.
Graham

I have 3 or 4 spare stock caps that came with the box of bits and bobs in the boot of that customer car too. But there was an Ambassador cap, a nice matching set of leads and a red rotor, so I thought "why not?"

Interestingly (or not) I has to pull the dizzy again and replace it 180 degrees out of place (so the vac unit faces forward) to get the plug leads to exit at the back of the Ambassador dizzy cap, is this normal?

Steve

[GrahamFountain]

Why would it not have worked to have taken the dizzy out, turned the engine 360 degrees, and put it back in?

Graham

[GrahamFountain]

Or is it the keying on the cap, not the lead positions?

[Carledo]

If it lasts a week, I'll be feeling a bit more confident. But right now, every shopping trip feels like a gambol.

Graham

I take it you mean GAMBLE! I now can't UNSEE the vision of you going down the road like a circus tumbling act!

Maybe i'm lucky, I don't seem to have much trouble with condensers, I buy mine from Fitchetts, where they come in a plain white box (God knows who make them) In extremis I get them from the factors (who deliver to me 5 times a day) when they are usually Intermotor. I've not yet had one duff out of the box, and I think only one that wasn't quite up to snuff after 3000 or so miles.

Way back in my youth, when I was servicing cars with Lucas dizzys in them all day, every day, we NEVER replaced the condenser on a service UNLESS the points showed evidence of condenser failure. A set of points got adjusted at 3000 miles and replaced at 6000. Plugs lasted 12k between changes. But there NEVER was a service interval for caps, rotors, condensers or leads and changing them out willy nilly was unheard of. Bosses and customers would both have protested loud and long. If 1 plug lead failed, you were expected to replace the duff one, the others stayed put!

I fit EI to save constant fiddling with the car, not because i'm unsatisfied with the performance of the part. I can't be bothered to KEEP tickling the points gap to keep it optimised then going through the rigmarole of timing. Nor, given the choice, do I tune and balance multiple SUs more than once a year. Once they are set up, there's no need! MY opinion is that most classic owners have much too much time on their hands and "The devil makes work for idle hands"

Steve

[Carledo]

Or is it the keying on the cap, not the lead positions?

It's the keying of the cap, I got the cap with leads separate so was able to fit the push in leads afterwards to suit the setup i'd produced. Number 1 cylinder on the rotor, nearest the block and forward which, IIRC, is where it's supposed to be and the dizzy retaining bolts near the centre of the vernier slots.

Steve

[GrahamFountain]

Is it just the princess cap that goes on backwards or do the Dolly 45D4 side entry caps go on that way too?

Graham

[cleverusername]

Just use a side entry ambassador cap and you will have no issues. I see no reason to keep the stock cap.

I have spares.
Graham

I have 3 or 4 spare stock caps that came with the box of bits and bobs in the boot of that customer car too. But there was an Ambassador cap, a nice matching set of leads and a red rotor, so I thought "why not?"

Interestingly (or not) I has to pull the dizzy again and replace it 180 degrees out of place (so the vac unit faces forward) to get the plug leads to exit at the back of the Ambassador dizzy cap, is this normal?

Steve

I am using exactly the same setup and I didn't have to do that. It was like for like replacement of the stock cap.

Which lets me use the cheaper rotor arms and any electronic ignition that fits the standard Lucas dizzy.

[Len Hughes]

I have one, NOS still boxed, it didn't work at all the one time I tried it in a Sprint.

Oddly enough, I had that with one I got from somewhere. Also, I went out for a bit today and had to keep kicking myself for thinking how well it went.

Personally, I hope the Distributor Doctor's condenser solves the problem. That will mean to me that the modern ones I got are rubbish and there's no other fault to look for. If it dies then there's a problem I might mask with a leccy unit. But will that just postpone another failure like the coil.

Thing is I've tried everything I can think of apart from going back to the old spark plugs - this all started when I did plugs, points, and condenser all at once. I have tried alternative points, dizzy, cap, leads, and a range of condensers. I've measured the voltage at the top of the coil with the points closed cold (5.8V @ 12V battery) and hot (6.5 @ 13V), both of which seem fine. The only other related issue I know of is there's no 12V boost from the starter solenoid. But I no more see the connection (pun) with that than to the plugs.

If it lasts a week, I'll be feeling a bit more confident. But right now, every shopping trip feels like a gambol.

Graham

Been running D D condenser in mine for a couple of years with no problem.

[GrahamFountain]

Been running D D condenser in mine for a couple of years with no problem.

Been to the shops and back a couple of times with no problems, or gamboling. But the first of the cheap ones lasted something like a month.

Graham