Twin carbs or not??

[Trikky2]

I ran these on my last bus and proved to be very good on a stock 1600.

Also very nicely priced
http://www.dellorto.co.uk/merchandise/products_details.asp?PartNo=TYPE%201%20ICT%20kit&CategoryID=12&PartsectionID=48" onclick="window.open(this.href);return false;

That looks a good deal - nice post

 

[froggy]

I had exactly the same questions as you and in the end it comes down to budget, if you can afford to go twin carbs then go for it, i decided i needed to spend money elsewhere and went for a 32 / 36 progressive. It runs like a dream, more power than stock and reasonable MPG.
Biggest problem with the progressives though is setting up the linkage to enable full throttle but i've got a mate that took it personal when i said people struggle with full throttle and wouldn't let me have the bay back without getting full throttle!
The only thing i will say is whatever you decide, unless your also going to get a decent exhaust to go with it then you wont get the best out of any set up!

 

[angus]

Ok - so if I went for these:
http://www.dellorto.co.uk/merchandi...o=T1-SP-ICTkit&CategoryID=12&PartsectionID=48
- would I need anything else to fit them.
Are these a good buy? (fitting to standard SP 1600)
I see machine7 do a very similar thing - could be the same in fact? £359 incl. VAT
$400 direct from CB Perfromance in the States...wonder if they will post....?!
Will I miss choke etc? (I doubt it)
Any disadvantages?

I guess I'll have to remove my air filter pedestal?
Anything else - apart from learning how to set them up!!

 

[angus]

Can I keep my standard old dissy?
What happens to vac advance?

 

[ronmidg]

have twin ICTs on my 1600TP split and the progressive on the bay with 2 litre T4 motor.

I can idle the the ICTs at 400/500 from cold with no hesitation on accel, and a ton more grunt low rpm than the old carb. Still running the vac dizzy with the line blocked and static advance at 10 degrees, contemplating drilling the carbs for a vac connection but havnt got my head round what size to drill for two cylinders drawing to emulate the standard with 4 cylinders drawing yet. Dont push the top speed so cant say if this is better or not.

The progressive varies between a pain in the bum and mildly irritable when its had 10 minutes to warm up. Cold idle has to be set at least twice what I use for the ICTs, there is always a hesitancy and then more than you want, like the early turbos, which must be the long unheated inlets.

 

[Benyon]

Ok - so if I went for these:
http://www.dellorto.co.uk/merchandi...o=T1-SP-ICTkit&CategoryID=12&PartsectionID=48
- would I need anything else to fit them.
Are these a good buy? (fitting to standard SP 1600)
I see machine7 do a very similar thing - could be the same in fact? £359 incl. VAT
$400 direct from CB Perfromance in the States...wonder if they will post....?!
Will I miss choke etc? (I doubt it)
Any disadvantages?

I guess I'll have to remove my air filter pedestal?
Anything else - apart from learning how to set them up!!

Just had these fitted to my twin port, the kit is complete except for additional fuel line.

Without a choke mine take approx 60 seconds to sit comfortably at idle and as ronmidg says idle is a lot lower than standard. I didn't fit mine myself so can't comment much but but my air filter and pedestal were completely removed.

Adv - pulls better up hills, again I don't puch top end but comfortable cruising speed has increase, running temp has decreased (but this could be just down to resealing the tinware), slight gain in MPG even at higher cruising speed.

Disadv - highlights even more how sh*t my Monza exhaust is!!

 

[cunning plan]

Ok - so if I went for these:
http://www.dellorto.co.uk/merchandi...o=T1-SP-ICTkit&CategoryID=12&PartsectionID=48
- would I need anything else to fit them.
Are these a good buy? (fitting to standard SP 1600)
I see machine7 do a very similar thing - could be the same in fact? £359 incl. VAT
$400 direct from CB Perfromance in the States...wonder if they will post....?!
Will I miss choke etc? (I doubt it)
Any disadvantages?

I guess I'll have to remove my air filter pedestal?
Anything else - apart from learning how to set them up!!

Without a choke mine take approx 60 seconds to sit comfortably at idle

How do twin carbs to so well without a choke?

 

[Guest]

i think its to do with shorter manifold distance and fuel atomisation, with a standard carb you have alot of fuel that gets condensed on the way to the cylinder head and before it get burned, so its wasted thus the need for a choke to allow more fuel to the cylinders.

Twin carbs = shorter distance for fuel to travel, less fuel wasted and better more complete combustion.

 

[ronmidg]

Anything else - apart from learning how to set them up!!?

Two issues I had, Could not reach the forward manifold nut on the RHS from the engine bay door, but have installed a T4 style top cover and this made in situ installation possible, have seen others say it is easier to remove the engine to install, and the back face of the cast manifolds is not machined and needed the fillet radius dressing to get the supplied nuts/washers to fit.

 

[Guest]

thats always a problem ron, i have a t25 lid to french in, its big but it should give good access.

 

[easy]

Remember doods, the trick with weber carbs is 3 pumps on the gas pedal before you turn over the engine and they will fire right up :wink:

 

[cunning plan]

i think its to do with shorter manifold distance and fuel atomisation, with a standard carb you have alot of fuel that gets condensed on the way to the cylinder head and before it get burned, so its wasted thus the need for a choke to allow more fuel to the cylinders.

Twin carbs = shorter distance for fuel to travel, less fuel wasted and better more complete combustion.

Good answer 8)