14 replies to this topic

[maxbrown336]

I was wondering what the benefit was in changing to a bigger carb or twin carb and if anyone had a recommendation to what may fit best. I have a 1275cc engine form a 1993 sprite. 

 

[cal844]

You could fit twins or an HIF44 but personally I wouldnt bother as you'll need to set the fuelling etc again

[nicklouse]

Next to nothing over the carb fitted other than for the person selling you it.

[mab01uk]

Many like the look of twin SU's but a single SU of suitable size and especially the later HIF SU's are much cheaper, easier to set up and keep in tune and can give the same or better performance on a good inlet manifold......especially if your Twin SU's are secondhand with some wear (which most are) because of the cost of new or properly refurbished twins.

[timmy850]

Twin carbs look cooler
They can also give better fuel distribution to the ports
I’m putting twin HS2 carbs on mine, because that’s what I’ve always wanted!

For a 1293, either a HIF44 or twin HS2 would probably be the right size, but you’ll only get a decent improvement to performance if your existing carb is holding back the engine

Any worn out carb will give dodgy results, single or twin. A good condition or refurbished carb won’t “go out of tune”

[Ethel]

Fuel distribution is a bone of contention with the A Series's siamese ports. There's an argument longer & twistier single carb manifolds mix it better.

[Spider]

Like a great woman, twins look ACE, but not nice to live with.

 

Fuel distribution is a bone of contention with the A Series's siamese ports. There's an argument longer & twistier single carb manifolds mix it better.

 

I've never found an issue running single carbs on appropriately sized manifolds.

[johnv]

Definitely twin SUs they look great on a mini, and same performance as the more modern single carb. And let's face it, it's more about aesthetics than performance these days anyway.. what modern shopping car wouldn't out perform a '65 'S'?

[blakie]

"Like a great woman, twins look ACE, but not nice to live with"

This is quite possibly the greatest ever explanation of twin carbs ever! It made me.chuckle anyway.............

Edited by blakie, 07 April 2020 - 08:12 AM.

[surfblue]

Only thing better than twin SU's.......

 

 triple su.jpg   9.93K   6 downloads

 

Or ..........

 

 4x su.jpg   8.67K   5 downloads

Edited by surfblue, 11 April 2020 - 05:01 PM.

[OzOAP]

Dellorto DFZs. Like a small pair of split Weber's.
Just built these up for my Innocenti

[Shooter63]

Dellorto DFZs. Like a small pair of split Weber's.
Just built these up for my Innocenti

Are those the ones with the accelerator pumps?

Shooter

[OzOAP]

Are those the ones with the accelerator pumps?

Shooter

Yep.
I have removed the choke butterfly and spindle for better flow, so can use the pump as cold start.

[Cooperman]

The original Cooper and Cooper 'S' both had twins, and it was a popular mod to fit a pair onto the old 850.

With all classic cars, and especially the Mini, it is good to drive a car similar to what was driven in the 60's when the Mini was 'the car to have' (unless you were rich, when a 3.8 Jag might have been the ideal).

I am about to re-build a pair of HS4's to fit to my 1990 Cooper 1330 road rally car. It may not go any better than with the HIF44 which it currently has, but to me it will be a real 'retro' drive and will sound and feel like my 1964 'S' rally car.

Once set up there is no issue with twin SU's and the settings last a very long time. I think the H4's on my 1964 'S' will need a rebuild soon as they have done a lot of work. A rebuild kit is cheap and they are easy to work on. It will just need balancing up mixture-wise when done.

Any difference in overall performance is not relevant these days as our cars are never 'fast road', just 'not quite so slow road'. If you drive a 60+ year-old designed car one thing you are not looking for is modern performance. It's about the 'retro' driving experience'.

[cal844]

Or twin 48 carbs on a C20XE 'Redtop' especially at 8500rpm on high lift cams ?

But yes a pair of HS carbs looks great

Edited by cal844, 12 April 2020 - 10:08 PM.