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25D distributor clearance

PostPosted: Tue Sep 06, 2022 10:05 am
by JohnMorin
Hi

I have an electronic distributor which I bought from H & H Ignition Solutions, they tell me that this is the electronic distributor that was sold by Paul Matty. As far as I can tell it is a 25D. See pic.

PXL_20220906_094008322.MP.jpg and


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I'm having a problem with clearance under the inlet tracts. With the old 23D distributor there was plenty of rotational movement available so that distributor could be oriented in different directions and have plenty of movement for timing.

Because of the extra height of the 25D and the bulkier cap there is very limited movement available and the leads point downwards bringing them too close to coolant pipes for my liking.

Can anyone throw any light on this, what is the correct orientation for this distributor?

Thanks

John

Re: 25D distributor clearance

PostPosted: Tue Sep 06, 2022 10:40 am
by Hawksfield
Thats a 43D Lucas They are not as versatile as the original dizzy but do fit and operate ok, I have mine with leads pointing at around 7 or 8 of the clock looking from the top, the clearance is ok but just.

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Re: 25D distributor clearance

PostPosted: Tue Sep 06, 2022 10:59 am
by JohnMorin
Thanks

That's about where mine is in my pics. How have you routed the leads?

John

Re: 25D distributor clearance

PostPosted: Tue Sep 06, 2022 3:04 pm
by webbslinger
With the tight clearance you risk damaging the delicate spring-loaded center post of the cap if you force the cap onto the distributor. Have you tried fitting the cap without the wires on? It should fit and that's how it should feel going on. You shouldn't feel the post interfering with the side of the rotor. I fit the cap without the top 2 plug wires because it's their boots that take the extra bit of vertical clearance needed to allow the uncompressed center post to clear the top of the rotor.

Re: 25D distributor clearance

PostPosted: Tue Sep 06, 2022 3:19 pm
by Mazzini
You can machine the body of the distributor down, where the clamp grips, this will give you the clearance you need.

Re: 25D distributor clearance

PostPosted: Wed Sep 21, 2022 11:56 am
by peterako
As John says above,

Looks like a 43D, which I als have had in my Elan. Bigger than the 23/25s.

But you will fit it if you make sure the lead orientation is away and down from the engine.

Probably did 40k+ miles with a 45D before going back to a 25D.

Peter

Re: 25D distributor clearance

PostPosted: Wed Sep 21, 2022 12:28 pm
by bitsobrits
Mazzini wrote:You can machine the body of the distributor down, where the clamp grips, this will give you the clearance you need.


Are you suggesting you can insert the distributor deeper into the engine? I don't think that's an option.

Re: 25D distributor clearance

PostPosted: Wed Sep 21, 2022 1:28 pm
by JohnMorin
Hi

Thanks all for your input. Today I modified the body of the distributor by moving the clamp shaft up by about 3.5 mm and then lengthening the shaft that goes into the block by the same amount. It would have been an easy job with a lathe but I don't have access to one. I had to file it down, it's a good job it's aluminium and I was a toolmaker in a previous life.

Anyway, I can now get the cap on with distributor in the normal position, but I can't get the cap on with the leads.

There don't seem to be any problems with the meshing of the drive pinion and the jackshaft.

Regards

John

Re: 25D distributor clearance

PostPosted: Fri Sep 23, 2022 2:00 pm
by JohnMorin
Hi

Even after the mods, which included reducing the diameter of the base of the shaft near the pinion to miss the burrs where the bore does not go right through the block, I still do not have enough clearance under the inlet tracts, or more correctly the carb mounting flanges, to mount the distributor in any other position other than with the leads pointing forwards and down at about 4 o'clock. It will work in this position position but I'm not entirely happy about the routing of the leads and the lack of clearance with other components.

I'll see how it goes and maybe look for a 23/25D alternative.

Regards

John

Re: 25D distributor clearance

PostPosted: Sat Oct 01, 2022 7:57 am
by JohnMorin
Hi

Gave up with the 43D. I bought a Powerspark distributor and coil, it's based on a 25D so with the cap on I can turn the distributor through 360 degrees.

John

Re: 25D distributor clearance

PostPosted: Sat Oct 01, 2022 8:38 am
by Mazzini
bitsobrits wrote:
Mazzini wrote:You can machine the body of the distributor down, where the clamp grips, this will give you the clearance you need.


Are you suggesting you can insert the distributor deeper into the engine? I don't think that's an option.


It is, I've done it and there is a thread or two on here if you search for it.