30 replies to this topic

[Bluemini]

But it ran fine on the last engine, which was the same spec, and same carb...

[Cooperman]

I had exactly the same thing on a 1293 Cooper 'S' rally car a few years ago. I put up the comp ratio to 11.1 to 1 and had this poor running. The dizzy was a standard Lucas Mk. 1 . Cooper 'S' unit. I got an Aldon 'Red' and installed that, but I still felt it could be better, so I called Aldon and spoke to Rob, who is really helpful. I sent the original Lucas dizzy back and included the full written spec of my engine. (trhe new 'Red' unit we used on a 1971 full-spec rally Clubman GT - see Jan 2004 Mini Magazine). Back came the completely re-built and re-curved dizzy for about £100. The difference it made when set up on the rollers was simply amazing and it started too. I also fitted a 560 Cold Crank Amp battery which made life much simpler when starting from hot.
I hope this helps.

Peter

[siggy]

You will find that no 2 engines are the same unless they have been blueprinted to the same spec.

Also when its on the RR the operater will be able to trace any faults.

Make sure you use someone with a good reputation with Mini's

Siggy

[Bluemini]

The place I normaly use is shut down

[siggy]

Spams not too far from you, we at least a lot closer than from here.

Siggy

[Bluemini]

Think I might treat myself to an Aldon, had a look at there website and they are quite resonably priced. Will ring them and see what they can recomend.

Other than that, i thought i could advance the dizzy so it runs well but wont start, and fit a second battery like on some rally cars so I can increase to power on startup.

[siggy]

The problem you have fitting 2 batteries is that it kills starter motors, and you have to wire in a split charging relay as used on caravans.

Just a thought have you checked the vacum and mechanical advance on the dissy

Siggy

[Bluemini]

The dizzy has had the vacume taken off, stripped the dizzy down and cleaned it all up, it all looks ok, but then again is there any noticable things that go wrong with dizzys?

[siggy]

The springs on the bob weights can stretch, the bob weights can sieze on the pivots, the spindle bush can wear and cause the dwell to 'wander'

Why did you disconnect the vac advance?

Siggy

[TimS]

surely ur going to need the vac advance if ur wanting more advance high up the rpm range. it does sound liek ur curve is completly off for the spec of the engine, y not get aldon to built u 1!

a trip to the roller might find the problem but its an expensive way!

if the cam timing is fine and when advanced it is ok except starting then that ur feeling points to ignition curve! fueling might need changed extreemly slightly but should b far off to give any problems.

i know what u mean about elec fuel pumps, my gf got rid of herd for the mech 1 because of the noise too. and the mech one should b fine up to about 90bhp and im sure ur not using all of that. so u shudnt be getting fuel starvation.


for ur vacume advance, i no on mien that the dizzy was advanced so much to suit the engine that the advance pipe wasnt used anymore.


my personal choice would be a perposefully built dizzy from aldon

[Bluemini]

I spoke to Aldon, i have 2 choices - expensive or expensive!! But possibly the best cure tho.

I stripped the old dizzy down that was on the engine originaly. (The vac had been removed before I bought the car Siggy) When I turned the dizzy drive by hand it sorts clunked round, so I did the same to a spare I had and it was a smooth action. I cleaned all the inards out and put it all back together, but it still didnt feel right when i turned it. So, I used the body of my spare dizzy, with the magnet section and electronic box off the original dizzy with the removed vac. When it was all back together I turned the drive again and it was smooth, but when I put the original body on the spare magnet section, that one became clunky.

So I'm thinkin that maybe the body got damaged some how when I took it off the old emgine, or the drive is worn/bent.

I put the new dizzy on the engine and it has made a big difference, it still aint 100%, but not far off, I just need to spend a few mins tweeking it till its right. I think the original dizzy has been modded to suit that engine, thats why I used the magnet section and electric box from it on the new dizzy.

[siggy]

Did you fit the bob weights from to old dissy to it?

I would refit the vac advance, that will improve the starting.

? Do you know what vac and mechanical advance do

Siggy

[TimS]

just what it says on the tinlol, the best thing i recon he could do is put the advance pipe back on, i was told that it hardly did anything on mine at the rolling road but iv noticed the difference! its got loads more torque, it idles quicker with the pipe on(due to it being more advanced) its loadsa better

[Bluemini]

The weights were the same in the two dizzys, but i think i will fit a new vac to it, gotta be worth a try!

If like you say, it will make starting the engine better, then i will be able to advance it a bit more and get it sweet.

[Bluemini]

I think its fixed.... almost!

I put a vac on it and tweaked the timing slightly and it feels loads better, still got a bit of judder at low revs, but soon pulls thru it. It seems a bit flat in 3rd tho when going up hill, but that could be down to the gear ratios (2.9 fd).

I think ultimatly, I'm gonna have to get it rolling roaded and invest in an Aldon dizzy tho.