Do you connect both Webber ict's to a svda dizzy or just one

[fozworth]

I've just got a set of Webber ict's and had read somewhere that you only need to connect the left carb to the dizzy vacuum and just block the right one .Is this correct .
Also what the best way to sort out the oil filler breather as i don't have any place for the pipe to go from the filler now .(I've got a billet type filler)?

 

[Trikky2]

Yes you can connect the vac advance to one carb.

For the breather you can tap a thread into the top of the filter and screw in a right angled hose fitting.

 

[fozworth]

Is it ok to just have one pipe going from the oil breather outlet on the filler neck to the top of one carb .Or do you need to have a breather pipe to the other carb also ?

 

[Trikky2]

One carb works just fine

 

[fozworth]

Do you know of any copper or brass elbow unions that are about 12mm ID for the breather fitting on the top of the carb filter?

 

[Trikky2]

I have used both gas and air line (compressor) fittings, bought at the local hardware supermarket.

 

[67westy]

Not often I disagree with tricky but If you connect only one then you get a very odd vacuum signal. I posted up a video of single connection and both, I'll find the links on a bit. I would suggest both and found it accelerated better than a single connection

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[67westy]

Vac signal from single carb (click to see the video):



Vac signal from both carbs (click to see the video):

 

[StuF]

Same here - mine didnt run right when connected to only one of my 34ict's so had to t-piece it off and connect to both
Probably down to a single carb not pulling enough vac considering they are only tiddlers compared to 40/42/44's
Although its a moot point at the minute as im back to my non vac advance dizzy after damaging the electrics in my other one!

 

[Trikky2]

Interesting you noticed a difference in driving the vehicle. I didn't.

I found the length and diameter of the vac tube, plus the reservoir size of the vac canister itself, smoothed the vac signal - because this and the points base plate mechanism itself, could not react fast enough to be affected by the vac signal shimmy shown on the gauge.

The gauge will react much faster than a vac advance mechanism.

The timing light did not show the shimmy measured by the gauge.

If this were not the case, how would the vac advance on two cylinder engines work?

I wonder if this is a peculiarity with ict carbs? I have not used them. My experiences are with 1776 and 2 liter plus engines fitted with Weber Idfs.

Either way, running the line off both carbs does no harm

 

[67westy]

I noticed hesitation. Similar to running an 009 so I guess it just wasn't advancing enough. With both hooked up it worked a treat. Maybe a stronger signal on the larger engines and IDF's?

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[fozworth]

Ok guys cheers ,although a bit gutted as I've just cut the new vacuum hose to length for one carb and blocked the other :-(( .I doubt I will have enough correct length to T peice off to connect the other . Incidentally does it matter if both vaccum pipes are different in length ?

 

[fozworth]

Same here - mine didnt run right when connected to only one of my 34ict's so had to t-piece it off and connect to both
Probably down to a single carb not pulling enough vac considering they are only tiddlers compared to 40/42/44's
Although its a moot point at the minute as im back to my non vac advance dizzy after damaging the electrics in my other one!

Do both vaccum pipes to each carb need to be the same length and does it matter if I run two equal length pipes from carbs behind the fan housing to keep things tidy then t piece them to the dizzy .?

 

[Trikky2]

Same here - mine didnt run right when connected to only one of my 34ict's so had to t-piece it off and connect to both
Probably down to a single carb not pulling enough vac considering they are only tiddlers compared to 40/42/44's
Although its a moot point at the minute as im back to my non vac advance dizzy after damaging the electrics in my other one!

Do both vaccum pipes to each carb need to be the same length and does it matter if I run two equal length pipes from carbs behind the fan housing to keep things tidy then t piece them to the dizzy .?

I can't see any reason why that wouldn't work

 

[Trikky2]

I noticed hesitation. Similar to running an 009 so I guess it just wasn't advancing enough. With both hooked up it worked a treat. Maybe a stronger signal on the larger engines and IDF's?

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Yes that might well be it.

 

[subheatadey]

Just to throw my bit in, I have twin ICTs and I had connected my SVDA but when I took it to the rolling road at Bogg Bros for tuning it was advancing it too quick so disconnected and blanked it off and running fine.

 

[fozworth]

What you blanked both carbs and dizzy vac ?

 

[subheatadey]

No just the dizzy is blanked off.