Dual dcnf's And Vacuum Advance Distributor

[Allen Lofland]

I have dual 40 dcnf's on the 2 liter in my scorpion. I have installed a Bosch Distributor from a Strado on the Lancia Zagato 2 liter exhaust cam this allows me to use 40/80 Alquati Intake cam that had no dizzy drive :)
Problem is...I have no vacuum advance ports on the dcnf;s. I have heard there are dcnf;s WITH vacuum ports. I am wondering if modification is possible or possible swap carbs with some one that has the ports and does'nt need them :)
The other question that has come up is this. EVEN with the ports it may not be a workable thing to run vacuum advance of dual carbs as they pulse to much ???? Any one out there with dual dcnf's and vacuum advance distributor experience.. Thanks

[Hamish]

Allen,
The man who might be best placed to help with this isWill but two cents:
There are many, many different DCNF varients..... :wink: so you should be able find something somewhere :roll:
As far as connecting up a vacuum advance all you need to do (I think :? ) is tap into one inlet track - that's what I had on dual DCOE carbs If you look at the GC website at his manifolds there's a single take off for the vacuum advance so shouldn't be too hard to do....
Ofcourse, you could throw caution to the wind and run a programmed ignition instead..... :twisted:

[Dmitry]

I have mount dizzy on exhaust cam on my HPE 2.0 then i install EFI to replace 36DATR 8O I have conected vac tube of FIAT CROMA 2.0 dizzy to special pipe from throtle body of Lancia Thema manifolid. This pipe connect befor throtle in idle and conect to intake pres. on open throtle.
I think you may connecting dizzy to one inlet track but you need use jet aprox. 0.2mm in vac line to decrease pulses of vacum. And you mast desconecting pipe when you ajusting ignition timing.
Many cars has no vac advance. I have lancia beta cope 1.3 engine. It has no vac advance. I have made VW beetle this summer. I bye 1942 cc engine from finland, it has 2 delorto 45 carbs and has no vac advance. It seems to my , if you has no conect that pipe, you have no problem.
Indeed, the best way is install microprocessor ignition microplex 1 from lancia beta xxxx ie, lancia trevy ie .

[Geoff T]

Allen,
My Euro Series II Monte runs a Magneti Marelli dizzy with no vacuum advance. You can have the advance curve on your distributor modified quite easily to negate the vacuum requirement. (lighter advance springs).
You cannot install a tap in the inlet manifold for vacuum advance! The tapping is in the carb for a reason. It must be upstream of the butterfly to work. If you use an inlet manifold tap, you will have full advance at idle and as soon as you open the butterfly, manifold vacuum drops to zero and no advance. Vacuum advance only works to advance the distributor during the initial acceleration stage until the engine rpm allows the centrifugal advance weights to bring the distributor up to full advance.
On your set up, you may notice a slight lag during initial acceleration at low rpm. Most European Fiats / Lancias did not have a vacuum advance system. I believe it was mainly for emission purposes. It will probably be easier to modify your distributor than to try and find a set of DCNF's with vacuum taps. You only need one carb to have the tap anyway.

Geoff T.

1982 Series 2 Montecarlo.

[Geoff T]

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[Otto-valvole-per-tutte]

Hi,

Maybe you could ask Tetsuo Onuki?

As he is using the same setup i guess:

http://www.ne.jp/asahi/montecarlo-x1/20/tune-up/tune31.html

:roll:

Cheers, Pieter

[Otto-valvole-per-tutte]

Hi,

Maybe you could ask Tetsuo Onuki?

As he is using the same setup i guess:

http://www.ne.jp/asahi/montecarlo-x1/20/tune-up/tune31.html

:roll:

Cheers, Pieter

[Otto-valvole-per-tutte]

Hi,

Maybe you could ask Tetsuo Onuki?

As he is using the same setup i guess:

http://www.ne.jp/asahi/montecarlo-x1/20/tune-up/tune31.html

:roll:

Cheers, Pieter