dx dizzy in a ex

[james butler]

if you put a dx dizzy in a carb engine do you have to set the timing the same as dx?
or do you keep the carb settings?
at the moment i am running ex settings and it runs fine but it occurred to me that the difference between the 2 engines would be timing related?

[GT_II]

My initial thought is that basic EX setting would be fine, but I suspect the advance and retard characteristics of a DX distributor will be different from an EX distributor, so it is likely a bit more complicated than that.

[mark1gls]

Not 100% sure but I think I read somewhere that the DX dissy has a better timing curve so you may get a little more power out of the engine compared to the EX dissy....

I could be making this all up????

[chopperoli]

Yeah go for it, time it up like DX initially, I think that means disconnect/plug the vacuum tube but you'll check that won't you. Any other mods? Weber carb? Are you in Brum too?

[unknownmale]

I'm running a distributor out of a DX in my EX on a weber, No issues at all, run on premium.

[scirocco_ne]

Sorry to hijack a little here but is the dx dizzy actually better in terms of how the car drives with it?

I may well fit one myself if so.

Thanks

[unknownmale]

I don't think you would realistically notice a difference. I believe the ignition curve is slightly different

[james butler]

i have currently set it up on ex timing and it drives very well but i wondered if it would be meant to be set at 6 degrees instead of the ex 18 degrees.
i suppose i coudl adjust it and just try it but i dont want to knacker any thing up as its quite a different timing setting.
in answer to your question chopperoli yes i have a weber on it, k&n air filter but thats about it and yes i am in brum.

[unknownmale]

I did mine by ear so not sure how many degrees mine is unfortunately.

I did have an issue when I first installed it, the most minut change and it would overun on shut off, or ping at high revs...A timing light would have been nice to have!

[james butler]

i have a timing light but not sure what pinging sounds like.
but it drove just like its supposed to so haven't been to concerned about it, more wondered if it should be in another position so doesn't cause any damage or maybe even gain some more power.

[mark1gls]

The “pinging noise” only happens when the car is under load, eg. If you are at low revs in the high gear - say 1500 rpm in 3rd and slowly press the accelerator down towards the floor and if you have the window open and head nearly out of the window you will hear a mechanical “pinking” noise. You won’t really hear it in the car with the radio on and windows done up.

I set my timing by advancing the timing till I hear the noise then retard it till it stops, a quite road and driving up a hill helps put the car under load..

[scirocco_ne]

i have a timing light but not sure what pinging sounds like.
but it drove just like its supposed to so haven't been to concerned about it, more wondered if it should be in another position so doesn't cause any damage or maybe even gain some more power.

Pinking sounds like cracking ice almost coming from under the hood. Its a clear sound resonating in the block

Its the spark hitting the piston if i remember right. It hit so many times on my old g60 in previous hands it welded a hole in piston top

Some people to set timing. Place the car under a high load scenario (4th up a hill foot flat to the floor etc) and advance the timing until pinking occurs and back it off a degree or two to finish.

It. can damage a engine long term through spark erosion so you always have to back a tad off the threshold of it starting to be safe

.

[james butler]

so is pinking caused by too much advance? so if you hear it retard the ignition slightly?
i will give it a go.

[mark1gls]

Yes that's right.

You can sometimes get a little bit "more go" out of the engine tuning it this way compared to setting it up with a light and to the book.

It does take just a little bit of movement on the dissy to make the difference, mark where your dissy is set at the moment then if it all goes wrong you can put it back to where it was before you started.