Dizzy Internals

[DamirGTI 327]

Right , i decided to fit one stronger spring for low down advance control just for the test and i need to repair/replace one nylon stop peg as it was damaged ..

 

Anyway heres how it looks form the inside :

 

Dizzy shaft and advance/bob weights down in the bottom (one for low down and one for top end advance control):

 

From top to the bottom - pick up coil , vacuum advance ring , cam with springs :

 

.. closer look :

 

Dizzy cam with two springs , this thin one is for low down advance control (i replaced it with stronger thick wire spring now) :

 

.. and this thick one is for top end advance control :

 

....................

[DamirGTI 327]

One view from underneath the cam :

 

Now , the spring stop peg which i had to replace (only the bottom part was left but i removed ti out completely before i made the picture ..) :

 

.. remains of the broken nylon peg :

 

.. they usually look like this (some kind of plastic/nylon material which stops springs from sliding off ) :

 

And my new stop peg which i removed from one old spare Ducellier dizzy :

 

Fitted in place and secured tightly with 2pack epoxy glue (just in case !) :

 

Damir

[jengis 0]

That's very informative Damir, thanks.

 

I have taken the free-play out of the strong spring in order to minimise pinking low down and allow more static advance, thus more max advance higher up - worked a treat, reved very sweetly on the 1.6 and now its on the 2.0 it's got more top end than I would have expected.

 

But I didn't know you could get the dizzy appart. I fiddled with customised pliers through the holes in the housing! In the process I broke the plastic spring retainers and had to bodge a bit of wire insulator on the end of the pin, as a temp fix (it has lasted over 3000 miles!) but I would like to mend it properly for peace of mind.

 

Info on how to dismantle it without breaking it would be fantastic!

 

Kev

[matty_gti 20]

Good read as allways damir!. Can you get stonger springs from Pug then?.

[DamirGTI 327]

Yes it's possible to dismantle the dizzy internals without damaging it theres a pin on the bottom on the shaft on the side which goes in the camshaft but i didn't try to press this pin out in order to dismantle it ..

 

First thing , you just need to release the springs from the end stops/pegs trough the dizzy aperture with some small thin flat screwdriver - but mark the end stops/pegs first so that you know which spring goes on which peg !! (remember theres one for low down and one for top end advance control ! so be aware that you do not mix up the places when you'll be refitting them back ..) then , remove the vacuum advance capsule , signal cable , an screw which will be on the side of the dizzy , working from the inside remove the two securing clips from the dizzy shaft , grab the pick up coil with your fingers and pull upwards out from the dizzy .. and thats it .. refitting is reverse of removal but sliding the springs back on the pegs is a little bit tricky ! be gentle as you might break the pegs .. anyway you'll made it with a bit of patience .

 

As for the replacement springs , no , you can't buy uprated springs from Peugeot as far as i know maybe from Peugeot Sport but certainly not from pug OE department ..

Anyway i found some stronger ones in old Ducellier dizzy from 309 car , and will test this the low down advance one , if it will be fine good , if not , it's easy to replace/remove it trough the dizzy aperture (no need to dismantle the dizzy to do so ..) either with some other one or with std. spring ..

Just don't touch/remove the other thick spring , it's for top end advance control so theres no need to replace this one .. the thin low down advance spring is the problem which couses pinking and this one need to be either tensed by bending the end stops/pegs , or by fitting stronger thicker spring (but you can as well bend the peg ..) ... need to note that you'll be doing this on trial and error basis .. try and see which combo works for your engine to eliminate low down pinking ..

 

Damir

Edited March 2, 2009 by DamirGTI

[Dave G 0]

how did you find the different with using both thick springs. thinking about doing this

Edited October 4, 2009 by Dave G

[DamirGTI 327]

Haven't tried that , but i imagine that the performance results will be very sluggish and with "??" total advance deg. .. now i don't know how "thick" you mean ?

 

I did try test with one step thicker initial spring and results where - a bit slow/sluggish acceleration from low to mid revs , and then snap on rushing from mid revs all to the rev limiter .. anyway for best performance you must have two springs of different thickness and tension (you can make tension adjustment as you wish by bending the spring end pegs..) as initial (usually thin wire) spring controls advance at low/mid rmp and second (thick wire spring) from mid to high rmp + rate of the both thin and thick spring determines total distributor advance deg.

 

This is a little bit tricky , theres one special tool for modifying dizzy advance curves in order to "precisely" suite engine specs :

 

 

 

Damir

[DrSarty 90 1 Cars]

This is a little bit tricky , theres one special tool for modifying dizzy advance curves in order to "precisely" suite engine specs :

 

Seems it needs a pair of arms off an older Indian fella too.

 

My God what a complicated and potentially tempremental state of affairs. This sheds even more light on older cars - like ours - losing power and having running issues. The larger components are probably fine but the smaller more fragile ones simply wear out.

 

Sorry to state the obvious there, but this means you actually get to see what is affecting your car as it ages. Springs losing their tension, lock nuts loosening, more fragile components breaking, HT leads breaking down, connections corroding and contamination etc.

 

I'm now a big fan of electronic fuel and ignition management.

 

Respect to those who stick it out and keep these older components running. Nice work Damir. They're not your arms are they?

[bensonmi 4 2 Cars]

not sure if its appropriate in this thread but worth a try before i open a new one, when using carbs with an 8 valve dizzy, what happens with the vacum advance? is it just blocked of? surely its needed to advance the curve but theres no where for it to go on carbs! just a problem iv come across today

nice work by the way Damir very informative

[DamirGTI 327]

Seems it needs a pair of arms off an older Indian fella too.

 

They're not your arms are they?

 

An old man with gray hair , glasses and this kinda hairy hands (no they're not mine !! i have much better looking hands )

 

Anyway , to be honest , im as well a bit sick and tired of this stone age engine management and ignition systems you simply can't squeeze full engine potential and performance using such systems with limited adjustment , it always have to be some sort of compromise , never the real thing with proper results as you've liked to be ..

 

Im waiting arrival of self learning SA ECU-s as there's still no one in this bloody country who knows how to map aftermarket ECU-s .. till then , im stuck with the stone age equipment ...

 

(i did try megasquirt idea , but adjusting it just makes me tear all my hair from the head i hate this programing stuff it's 110% boring and complicated dunno why this things can't be a little bit simpler ?! ..)

 

Damir

[DamirGTI 327]

not sure if its appropriate in this thread but worth a try before i open a new one, when using carbs with an 8 valve dizzy, what happens with the vacum advance? is it just blocked of? surely its needed to advance the curve but theres no where for it to go on carbs! just a problem iv come across today

nice work by the way Damir very informative

 

You can block the vacuum advance plate , but me thinks that this isn't necessary , im using mine on modified engine with just disconnected vacuum hose for good few years now without any issues .. vacuum advance unit is said to improve fuel consumption at low/part throttle (while cruising when the vacuum inside the inlet manifold is high) by advancing the timing a little bit , but i haven't notice difference in fuel consumption when i had standard engine driving with and without vacuum unit connected ... for modified engine it isn't needed , much more important stuff is re-curving the dizzy so that the advance curve suits all the engine mods .

 

Damir

[bensonmi 4 2 Cars]

You can block the vacuum advance plate , but me thinks that this isn't necessary , im using mine on modified engine with just disconnected vacuum hose for good few years now without any issues .. vacuum advance unit is said to improve fuel consumption at low/part throttle (while cruising when the vacuum inside the inlet manifold is high) by advancing the timing a little bit , but i haven't notice difference in fuel consumption when i had standard engine driving with and without vacuum unit connected ... for modified engine it isn't needed , much more important stuff is re-curving the dizzy so that the advance curve suits all the engine mods .

 

Damir

 

 

excelent so all i need is the dizzy advanced slightly and it should be as good as it gets, cheers for clearing that up for me

[jengis 0]

.. anyway for best performance you must have two springs of different thickness and tension (you can make tension adjustment as you wish by bending the spring end pegs..) as initial (usually thin wire) spring controls advance at low/mid rmp and second (thick wire spring) from mid to high rmp + rate of the both thin and thick spring determines total distributor advance deg.

 

Damir

 

 

Just looking at what you have said about the sring rate determining total advance. I actually thought that these dizzy's (and most others) hit max advance around 4k rpm and it was capped because it hit an end-stop. So, as I understand it, the spring rates define the point in the rev range when total advance is reached. Whatever springs are fitted it will still only allow a certain amount of advance. I agree that upping the rate of the weak spring (or bending pegs) will reduce the low down rate of advance and the strong sring will affect mid-range rate of advance (and so peak at higher rpm), but If I'm correct they don't determine total adavance - that is set by the dizzy architecture and the amount of static advance.

 

Is this not the case?

 

Kev

[jengis 0]

excelent so all i need is the dizzy advanced slightly and it should be as good as it gets, cheers for clearing that up for me

 

But that would increase the total advance - this is surely the most important thing to set right with a tuned engine. Don't think you should worry about part throttle openning emmisions/drivability/economy if it means the full load setting is compromised. In my experience its the exhaust emissions when driving at 2-3k rpm and comming on and off the throttle when cruising at steady speed rather than any loss of fuel economy that is most noticable with it disconnected.

[DamirGTI 327]

Just looking at what you have said about the sring rate determining total advance. I actually thought that these dizzy's (and most others) hit max advance around 4k rpm and it was capped because it hit an end-stop. So, as I understand it, the spring rates define the point in the rev range when total advance is reached. Whatever springs are fitted it will still only allow a certain amount of advance. I agree that upping the rate of the weak spring (or bending pegs) will reduce the low down rate of advance and the strong sring will affect mid-range rate of advance (and so peak at higher rpm), but If I'm correct they don't determine total adavance - that is set by the dizzy architecture and the amount of static advance.

 

Is this not the case?

 

Kev

 

Yes , think you're right with that one , did miswirite something wrong ... so lets put it this way :

 

Total dizzy advance = initial advance (by swinging the dizzy manually backwards/forward) + vacuum advance (if the vacuum canister is in good order and with vacuum pipe connected) + centrifugal advance (combo of bob weights and springs fitted inside the dizzy)

 

Agreed with the spring rate and tension as well , they'll determine how fast and at which rmp will timing reach maxi advance ..

 

Damir

[DamirGTI 327]

excelent so all i need is the dizzy advanced slightly and it should be as good as it gets, cheers for clearing that up for me

 

Depends on what you've done with the engine in terms of modifications , if it's modified engine you wont gain much just by advancing/swinging the dizzy on advance/retard side as the stock dizzy advance curve will hardly be suitable for moded engine , i mean , it'll still work with the std. dizzy but you wont be able to unleash full engine potential ..

.. it'll have to be re-curved to suit all engine mods and after the re-curving job is done all you'll need to do is adjust the timing and that's it ..

 

Damir