Twin Carbs Vs Single Carbs (Stock)

[Verdey0]

I recently got a 4k-B twin manifold/carb setup, curious as to what benefits it has over a single carb?

Tried googling but due to being so scarce, I can't find much about them.

 

Any help, tips or knowledge would be greatly appreciated!

Edited September 16, 2014 by Verdey0

[7000rpm]

It would help volumetic effeciency because you havent got 4cyls trying to all feed of one little carby.

[coln72]

The 3K-B carbs made my 5K idle smoother. Also felt it accelerated harder with the twins. Was noticeable when the linkage fell off one carbie.

[GJM85]

I would kill to get one of these set ups.

[coln72]

My first set cost $25 which included everything :)

 

[Mechanical Sympathy]

A set went for $130 on eBay last week.

 

I had been bidding on it only because I thought it was far too cheap and only let it go because I already have a set.

 

The winning bidder was bidding in $5 increments so it could easily been sniped at the last minute. Or maybe it was you Dean?!

 

I think they're worth more than that.

[airocobra]

These will not give you a big preformance increase and best used with a mild cam ( but not essential ) . If they have not been rebuilt , then they will need to be . Both cabs need to be in (same -- same) condition or it will be impossible to tune and they will run like a hairy dog. If you do not have the STD aircleaner unit , then an after market aircleaner set up can be hard and expensive to find . So what I am tring to say a replacement weber carb can be easyer solution , both economic , power and tune . But if you want the old school look with a bit of old school induction noise , then they are the go !

 

 

Edited September 16, 2014 by airocobra

[coln72]

My second set was made up from a manifold that was given to me. Used a couple of standard carbs, dodged up a linkage out of old fuel hose. I got hold of a couple of old Speco aircleaners similar to the above. To these I brazed the bases out of a couple of old Corolla aircleaners so they would fit up to the carbies. With a cam and exhaust they would allow the 5k to spin over 7500 rpm and beyond if I was feeling nasty.

 

pics here

http://www.rollaclub.com/board/topic/12720-mytoy-ke20/page__p__173678__hl__+mytoy#entry173678

Edited September 17, 2014 by coln72

[Verdey0]

Wow appreciate the replies!

I also have a worked 4k, cam & balanced bottom end so I'm told.

 

Carbs may perhaps be for sale.. for the right price and I have no idea what that is! Haha

[redvalkyrie]

So, are those two Aisan carbs on that 3K-B manifold both big single barrels or two smaller barrels for each carb? Anyone tried running two Weber 32/36 or 38/38s on a twin manifold?

[altezzaclub]

My Weber list says-

Corolla 1200 (3K I assume) 1x40 DCOE with 27mm chokes

Celica 1600 1x45 DCOE with 28mm chokes

Celica 1600 2x42 DCOE with 27mm chokes

Corolla 2TC 1x40 DCOE with 30mm chokes

Corolla 1600 (probably 4AGE) 2x40 DCOE with 27mm chokes

 

So feeding 1600cc they recommend two barrels with 28-30mm chokes, or 4 barrels with 27mm chokes. One Weber 32/36 easily feeds a 2L engine, and someone on here who tried different chokes said the 27mm worked best. Larger chokes kill air velocity at lower revs so it won't suck fuel out of the jets.

 

If you're modding stuff madly then a DCOE will be better than the downdraughts, apart from the look. Richo has a single DCOE 40mm on his 5K with balanced bottom end and 290deg cam, it seems to pull fine right through the rev range. I think he's using 28mm chokes.

 

If you want to use twin Aisans, read this-

http://www.rollaclub.com/board/topic/44694-3k-twin-aisan-carby-setup/