Vacuum Does not beat as it Sweeps as it Cleans

[sloopjohnrb]

I need to replace the vacuum unit as it is a deffo goner.
Gladys, 1962 948 cc

Lucas 5-8-3 54418247 DM2 are the numbers on the Vacuum.

However, I'm not sure if the Dizzy has been upgraded to one of the 1098 ones
40561 L BN 260 262

The problem is that the car has a metal vacuum pipe from the Vacuum to the rocker cover, yet the Vacuum itself seems to be the push on pipe type-it seems the previous owner codged the 2 together.


Is it possible to remove the metal piping and replace it with the push-on piping?

I'd appreciate any input

[billlobban]

Before you go to the cost of replacing the vacuum advance mech have a look here
http://www.simonbbc.com/automotiveshop/
and compare the prices against a complete new dizzy

[bmcecosse]

Exactly - these dizzy prices are amazingly cheap - especially the later/better 45D at £30!

[sloopjohnrb]

Do you not have to change the polarity?
This place says all their products are Negative Earth.
Gladys is positive .

[alex_holden]

Do you not have to change the polarity?
This place says all their products are Negative Earth.
Gladys is positive .

The distributors with points will work OK on either polarity. Only the electronic ones care whether the car is positive or negative earth.

[sloopjohnrb]

wow, thanks, I din't know that

[billlobban]

Even if you decide on the electronic version its very easy to change polarity

[bmcecosse]

And a good idea anyway - the general change to -ve earth on cars was to help with rust problems! Slightly less tendency to rot away in the wet.

[sloopjohnrb]

I've spoken to the guys at Simon bbc.

The problem seems to be that there is a lead going to the side of the Dizzy, that doesn't seem to fit with buying a normal points 25 D.

Please see attached picture-what becames of the lead that fixes onto this point on the Dizzy, with smallish nut?[frame][/frame]

[billlobban]

The bit with the small nut is a vacuum pipe from the carburettor to the distibutor. You can buy a 'Push On' vacuum pipe as a complete thing Or you can find a simple push on connection that will connect the existing pipe (push the nut away from the pipe end) to the 'Push On' carburettor connection[frame][/frame]

[alex_holden]

You could replace the terminal on your wiring loom with a spade connector as fitted on later cars.

[sloopjohnrb]

Hiyas
Thanks for the info on the vacuum pipe, I reckon I can get the push on to fit to the existing metal one as suggested.

By the "nut on the side", I meant that there is a power lead that fixes on to the side of the Dizzy, the fitting circled here in red, and secured by a small nut.

It's this wire that's being the bug-bear.
yes, I could put a spade connector on, but so far, honestly, I don't know where it goes to if I fit a new 25d Dizzy from Simonbbc.

Simonbbc says it's an earth lead that should go to the coil-but there's already 2 leads to go to the coil, one neg, one positive.
Can this other lead go to the coil as well?
If the existing 2 leads, and the lead that goes to the Dizzy side can all go to the coil-problem solved.

However, if the lead from the dizzy's side has to REPLACE one of the 2 leads that goes to the coil-then I'm back to square one again, with a lead with nowhere to go to.

Also, I removed the Dizzy without disturbing the cotter so as to keep the timing on line.
Simonbbc's Distributors comes without the fixing plate and the cotter-so am I right in thinking that I will have to remove fixing plate and cotter from old DIzzy, put onte a new 25D, and re do all the timing?

Sorry if I seem so unknowledgeable, but I'm not being deliberatery obtuse-rather I've been struggling for a while with this one

Thank you again for your massive help.[frame][/frame]

[billlobban]

Sorry I mistook what you were saying for the vac advance mechanism.

If you buy a new distributor no matter who you buy it from and no matter whether it is positive or negative earth it is wired up exactly the same as the old one. One wire to the coil and one wire from the other side of the coil to the distributor exactly the same as before. All you will have to change is the type of connection on the wire which was originally connected to the distributor (as explained above by alex).

You will have to fit your old 'fixing plate' to the new dizzy and re-time the engine. But thats easy to do.

(Please note that if you are buying the electronic(no points) version of the distributor the wireing will be slightly different)

[alex_holden]

Yes, a new points-based distributor will have a single spade terminal that serves the same function as the screw terminal on yours. The existing wire does go via the loom to one of the coil terminals (should be the positive one if your car is positive earth).

If you were to change to negative earth and fit an electronic distributor then it would come with two wires instead of a single terminal. You would connect the wire that is energised by the ignition switch (can't remember its colour off the top of my head) to the coil's positive terminal, and the two wires from the distributor would go to the two coil terminals.

[bmcecosse]

The later 45D dizzy is far better - and £20 cheaper! Just make the electrical connection as before - the wire that went to the old dizzy - attach it to the new one! Change the terminal if necessary.