DUAL VS SINGLE CARBS
DUAL VS SINGLE CARBS
Hi Guys
How do you decide whether to install a single carb or go for dual carbs.
Do you get better performance from smaller carbs in a dual set up than a bigger single carb?
Is there a large price difference?
excuse the ignorance but any advice will be appreciated.
Thanks
G.
How do you decide whether to install a single carb or go for dual carbs.
Do you get better performance from smaller carbs in a dual set up than a bigger single carb?
Is there a large price difference?
excuse the ignorance but any advice will be appreciated.
Thanks
G.
- Merlin
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Obviously two carbs cost more, plus you need all the plumbing, linkage, etc.
win carbs CAN be more fuel efficient - depending on the carb used, and the engine they're combined with.
If you floor it though, they will drink at twice the rate of a single one.
It depeds what you want...each combination affects the noise output, consumption, performance, etc.
Just plonking two carbs onto a stock engine is not going to give you a massive performance increase, etc.
A single bigger carb is usually more fuel efficient.
A decent twin-carb setup will cost you 4k absolute minimum, to 8k or more depending on what you do and use.
N.
win carbs CAN be more fuel efficient - depending on the carb used, and the engine they're combined with.
If you floor it though, they will drink at twice the rate of a single one.
It depeds what you want...each combination affects the noise output, consumption, performance, etc.
Just plonking two carbs onto a stock engine is not going to give you a massive performance increase, etc.
A single bigger carb is usually more fuel efficient.
A decent twin-carb setup will cost you 4k absolute minimum, to 8k or more depending on what you do and use.
N.
"Understeer is when you hit the wall with the front of the car, and oversteer, the rear.
Hp is how fast you hit the wall, and Torque is how far you take the wall with you."
Hp is how fast you hit the wall, and Torque is how far you take the wall with you."
sled wrote:well obviously the UK is wrong.
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whats your application? Too many variables, you need to be more specific
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Just my humble opinion.
Single carbs work well as long as manifold velocity is high like a 1200 or 1500 singleport with small manifold diameter and heated at the bottom with exhaust gas.When manifold diameter is increased,velocity decreases causing fuel droplets to fall to the bottom.This causes flat spots.This has to be compensated for with a richer main jet, increasing fuel consumption unneccecary.The car magazine tested the twincarb sp beetle using considerably less fuel than the single carb version.
You have to remove them before you take out the engine.(unless its a beach buggy)
Once bought a set from a mechanic. He could not synchronise it and replaced it with a single carb.
Fitted it on a 1300 dual port with commonsense and precision,and ran like a dream.Also helped a friend over the phone to synchronise a set, it is really easy and Quick if you are a perfectionist, no tools or gauges needed, but totally impossible if you are a typical crude watercooled mechanic.
Several people have experimented modifying the type 1 engine for better efficciency (using less fuel and more power than standard)(People like John Carcey in the USA comes to mind,early eighties,still have the articles somewhere.)All ended up with small duall carbs.
The first Porsche had a beetle engine with dual carbs.
Big single carbs are simply inefficcient and thirsty.
Engine dyno tests in overseas publications mostly came to this conclusion.
But,this is just my humble opinion.
Single carbs work well as long as manifold velocity is high like a 1200 or 1500 singleport with small manifold diameter and heated at the bottom with exhaust gas.When manifold diameter is increased,velocity decreases causing fuel droplets to fall to the bottom.This causes flat spots.This has to be compensated for with a richer main jet, increasing fuel consumption unneccecary.The car magazine tested the twincarb sp beetle using considerably less fuel than the single carb version.
You have to remove them before you take out the engine.(unless its a beach buggy)
Once bought a set from a mechanic. He could not synchronise it and replaced it with a single carb.
Fitted it on a 1300 dual port with commonsense and precision,and ran like a dream.Also helped a friend over the phone to synchronise a set, it is really easy and Quick if you are a perfectionist, no tools or gauges needed, but totally impossible if you are a typical crude watercooled mechanic.
Several people have experimented modifying the type 1 engine for better efficciency (using less fuel and more power than standard)(People like John Carcey in the USA comes to mind,early eighties,still have the articles somewhere.)All ended up with small duall carbs.
The first Porsche had a beetle engine with dual carbs.
Big single carbs are simply inefficcient and thirsty.
Engine dyno tests in overseas publications mostly came to this conclusion.
But,this is just my humble opinion.
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Well put Dawie.
I do think the sound of twin IDFs is something that connot be replaced, for me, I just love it. And yes, properly setup, they are very light on fuel, but anything near a slightly heavy foot means big fuel bills - hey I'm in it for fun, not fuel saving
I do think the sound of twin IDFs is something that connot be replaced, for me, I just love it. And yes, properly setup, they are very light on fuel, but anything near a slightly heavy foot means big fuel bills - hey I'm in it for fun, not fuel saving
ANGRRR
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vader wrote: The Force is strong with you young Sith Lord Z!
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As a interesting aside, we recently discovered that my Mother's '66 runs twin Weber ICHs...instead of the expected ICTs.
IMPI or myself had never heard of these, so I Googled them, and they have a very good reputation, if anyone is interested.
Will find the link later...
N.
IMPI or myself had never heard of these, so I Googled them, and they have a very good reputation, if anyone is interested.
Will find the link later...
N.
"Understeer is when you hit the wall with the front of the car, and oversteer, the rear.
Hp is how fast you hit the wall, and Torque is how far you take the wall with you."
Hp is how fast you hit the wall, and Torque is how far you take the wall with you."
sled wrote:well obviously the UK is wrong.
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- Merlin
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http://www.innerauto.com/Weber_Brand/We ... arburetor/I wrote:As a interesting aside, we recently discovered that my Mother's '66 runs twin Weber ICHs...instead of the expected ICTs.
"Understeer is when you hit the wall with the front of the car, and oversteer, the rear.
Hp is how fast you hit the wall, and Torque is how far you take the wall with you."
Hp is how fast you hit the wall, and Torque is how far you take the wall with you."
sled wrote:well obviously the UK is wrong.
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A set of 40mm Solex Kadrons which are simillar in price would be a much better option, the best aftermarket carbs I have worked with, easy to set up, plenty advice available and if you ever decide to up the cc's will cope up to 1900cc, I would go with the Kadrons for a 1600cc, they fit & run right out of the box, I have 2 sets.
For what it's worth, ignorance has no limits ......