Distributor Clamp Solution

[carrierdave]

Hi all,
I seem to remember coming across a web site that had a solution to the over tightened/cracked collar, where the standard Ford plate holds the distributor in place.

The solution was to remove the old cracked casting and then the new machined bracket would clamp around the shaft and bolt to the block as normal.

Has anyone else seen this? It could be an inexpensive solution for a number of us on this site.

Thanks

Dave

[carrierdave]

Just answered my own question - QED

http://qedmotorsport.co.uk/qed-shop/vie ... istributor

Ive been looking for this for months!!!!!!!!!!!!!!!!!!!!!!

[Orsom Weels]

Hi Dave,
Sue Miller has these clamps in stock, apparently Mick sourced them, they've sat on the shelf ever since & she very kindly let me bring one home to try. I have machined the remains of the cracked clamp ring from an old distributor body & tried it in a spare block I have, the main problem I can see is due to the thickness of the new clamp,(13mm, as opposed to 3mm for the original steel clamp) it holds the distributor so far out of the block that the gear only just contacts the drive gear on the jack shaft, if it used the flat drive peg drive as most others did, it would not engage at all !. I'm not sure how this would hold out if used in anger & it also looks like it will make the distributor cap very tight under the carb. My first thought was to machine the clamp a bit to allow the distributor to drop in further, but this would then intrude into the clamp bolt thread & render it useless. As & when I have the time I'm looking at adapting/modifying things to see if I can make it all work, I guess I'm going to have to do more work on the distributor body.

Regards, Tim

[carrierdave]

Hi Tim,
Some very good points. I can see if the gear wheel is just about engaged on the jack shaft you could run the risk of jumping a cog.

I have been in the garage this afternoon looking at the distributor body too see how much needs to be machined off ? and then looking at the picture on the QED web site I did have the same thought.

Would the QED one fit over the upper ring on the dizzy, so that it is level with the face that sits on the block?

That?s the only way I could see it working

Dave

[Orsom Weels]

Hi Dave,
The best I can come up with is to machine the remaining flange on the dizzy (which sits on the clamp to govern the depth) Down to the size of the original clamp ring, then counter bore the new clamp to a depth of 8-9mm to allow the dizzy to drop into it. the flange is too large to just bore the clamp to that diameter, that would also break into he clamp bolt thread. This looks as if it should allow the dizzy to drop in to pretty much the same depth as standard, certainly enough to get good tooth contact on the drive gear, while still leaving plenty of strength in the clamp. This is all penciled in as one of those winter projects, if anyone has any better ideas, I'm all ears
Regards, Tim

[Elan45]

Dave/ Tim / Others,

I have repaired a couple of 23D dizzies by chucking the body into my lathe and machining all the old ring completely off. Then I made a new solid ring and either pressed it onto the body or locked it with Primer T and Loctite RC680. Then the original steel clamping bracket was straightened and used.

A large part of the problem is that the original ring casting is not solid and the alloy casting is not strong enough to withstand overtightening.

Perhaps I should make up a batch of rings for sale.

Roger

[ceejay]

The very first time I attempted to adjust the ignition timing on the
Twin cam engine I wondered who the clown was that designed the
distributor holding clamp.... mmmm, I thought, there's many jokes
about how Lucas stuff won?t work unless there's plenty of smoke,
maybe the same goes for the mechanical side of things?

The fix is quite simple, I did this way back in the eighties,
I've just posted an article at our blog, you can learn how to modify the
distributor clamp arrangement here:
http://elantrikbits.com/lotus-elan/?p=233
Ceejay

[Orsom Weels]

Hi Roger,
Yes, that is something I have looked at aswell, I was thinking a slightly undersize ring, heated & shrunk on to the dizzy but I guess an adhesive of some sort would work equally well.
I'm continuing trying to do something with the clamp from Sue as she asked for a bit of feedback on whether they would work or not. So far, looks like yes, it could work but requires quite a lot of modification to do so. It would be interesting to hear what QED say about using theirs, in the pic's, it looks identical to the one I have from Sue.
If you're lucky enough to have a dizzy with an undamaged clamp ring, you can stop it becoming a problem by filling the gap with one of the metal repair compounds that are widely available, I've used 'Quick steel' to good effect, once filled & hardened, you can tighten the clamp as much as you like without the ring being able to collapse. The dizzy on my car at the mo actually has half of it's original ring & the remainder built up with the Quick steel & filed roughly to shape. An emergency repair earlier this year that's still working ok.
Ceejay, A differnt take on the idea, if I have it right, you clamp the replacement ring to the dizzy, then use the secondary clamp, with the bolt into the block to hold it all in place. Which one do you use for adjustment ? I'm guessing you can use either ? This does have the advantage of getting rid of the original crap steel plate clamp but with more new parts to make. I suppose it depends on what facilities you have. (Do you have a pic of the distributor body clamp 'not' fitted to a dizzy ?)

Regards, Tim

[ceejay]

Tim.
This method works extremely well, as I said in the article I did this mod way
back in the eighties, I don't recall taking any photos as I did the mod.

The ring that is clamped to the dizzy body is not used for adjustment,
the 3/16" cap screw is only used to clamp the ring securely onto the dist body....
A heat shrink fit ring would work OK, but I opted for an adjustable - removable item.

The main plate applies the clamping force, and it does not require much
pressure from the 1/4" UNC stud to hold it in place.
I know a lot of guys may not have a lathe, or the required machining
skills, but it is a worthwhile mod, as it makes the job of adjustment
of he dizzy/timing so easy.

Like you, I also thought the original holding plate was absolute
crap engineering.
Col.

[elj221c]

Like you, I also thought the original holding plate was absolute
crap engineering.
Col.

However, it simply worked on thousands, no, millions of cars!

Fitted and timed once in the factory it managed thousands of miles per unit.

Perhaps it just wasn't a design for us 'tinkerers'!

[billwill]

And of course originally Lotus, perhaps, did not intend the main clamp to be moved often. My car originally came with a 25D4 distie, which had a vacuum unit not connected, but a very handy knurled knob to do the fine adjustment of the timing.

I was slightly annoyed when a later refurb, replaced that distie with one that did not have that feature.

Photo from: http://www.simonlacey.com/pages_new/con ... ebuild.htm

[types26/36]

[quote="billwill"]I was slightly annoyed when a later refurb, replaced that distie with one that did not have that feature./quote]


Well I would have been very happy that someone had the foresight to fit the correct distributor, TC?s were not supposed to have had the vacuum distributor, the vernier fine thumb screw adjustment was fitted to most of the British cars of the 60's.....mini?s, Morris 1000?s, Anglia?s, Cortina?s etc.etc. except for the TC and the Cooper S which did not have the vacuum/thumb screw adjustment.
All of these cars had the wrong advance curve for the TC and unless your old vacuum distributor had a modified advance curve then it was wrong, I suppose the thumb screw adjustment could be of minor use to fine set the timing.
If you want a distributor with a vacuum and thumb screw I probably have one kicking about somewhere and will willingly swap it for your non vac distributor.

[billwill]

I was slightly annoyed when a later refurb, replaced that distie with one that did not have that feature.

Well I would have been very happy that someone had the foresight to fit the correct distributor, TC?s were not supposed to have had the vacuum distributor, the vernier fine thumb screw adjustment was fitted to most of the British cars of the 60's.....mini?s, Morris 1000?s, Anglia?s, Cortina?s etc.etc. except for the TC and the Cooper S which did not have the vacuum/thumb screw adjustment.
All of these cars had the wrong advance curve for the TC and unless your old vacuum distributor had a modified advance curve then it was wrong, I suppose the thumb screw adjustment could be of minor use to fine set the timing.
If you want a distributor with a vacuum and thumb screw I probably have one kicking about somewhere and will willingly swap it for your non vac distributor.

[/quote]


My earlier version of the Elan Workshop manual shows the distie with the Vacuum fitting.

It's unlikely to have had the wrong settings, the car was built by Ian Walker for Malcolm Ricketts & he part exchanged it back to Ian Walker after about a year and a bit and I've had it ever since. Malcolm did a fair amount of hill-climbing in it, I understand.

The advance curve in these disties is set by the strength of the springs on the weights (and the stop 'tongue') and is therefore fairly easily changed, yet hard to tell that it has been changed.