3k Twin Aisan Carby Setup.

[Des]

I'm thinking about twin aisan carbies on my Ke11.

 

All throat sizes are 27/27 mm. 3K and 4K venturi diameters are:

 

* 21/24 mm for single carb

* 20/22 mm for twin carb motors (3K-B, 3K-D).

 

Jet sizes are:

 

* 0.99/1.75 mm for single carbs

* 0.84/1.40 mm for twin carbs.

Stolen from the FAQ.

 

So are the 3kb carbies the same as a single 3k carby not including the Jets and Venturis ?

[Andy43]

I have a box full of 3k carbys all off single carby 3k's

Primary venturi could be 17, 19 or 21mm

Secondry venturi could be 24 or 25mm

Jet sizes .91mm up to 1.77mm.

 

The Yellow book claims the carbys are the same, with different venturis and jetting.

The venturis can be poped out of the carby if your careful.

The Secondry Venturi is about 6mm shorter in length than the Primary one.

I have been playing around with Primary Venturi size, and are currently running 25mm in both pri and sec and while It pulls good when reving hard, the idle performace is not good.

The mixture seems to bounce from rich to lean at random.

 

But back to the question.

Yes I think they are the same.

 

Hope that helps

Andy

Edited September 6, 2010 by Andy43

[coln72]

Ran a couple of sets of 3kb carbies over the years and never ran the original carbs. Always bolted on a pair of "single" carbies onto the manifold. Seemed to run better on a 5k. So they are interchangable as long as the carbie linkage is the same as the 3kb carbie. Early and late have different linkage set ups where they connect to the cable.

[Andy43]

Ran a couple of sets of 3kb carbies over the years and never ran the original carbs. Always bolted on a pair of "single" carbies onto the manifold. Seemed to run better on a 5k. So they are interchangable as long as the carbie linkage is the same as the 3kb carbie. Early and late have different linkage set ups where they connect to the cable.

 

 

Colin

Just as a matter of interest how much difference between the single and twin set up.

Thanks

Andy

[Des]

Ran a couple of sets of 3kb carbies over the years and never ran the original carbs. Always bolted on a pair of "single" carbies onto the manifold. Seemed to run better on a 5k. So they are interchangable as long as the carbie linkage is the same as the 3kb carbie. Early and late have different linkage set ups where they connect to the cable.

Did you jet it down at all for the 5k or just 2 stock 3k carbies ?

[Felix]

Did you jet it down at all for the 5k or just 2 stock 3k carbies ?

 

With twin aisan's the motor doesn't see twice as much carburetion. Just see's less intake path resistance. Think about it from the intake ports point of view looking up the manifold... How many carb throats would it see with a single carb, and how many throats would it see with twin aisans? The same.

 

Twin aisans are overrated, unless you are after originality. The aisan carbs are the most unreliable part of a corolla.

Edited September 7, 2010 by Felix

[Des]

With twin aisan's the motor doesn't see twice as much carburetion. Just see's less intake path resistance. Think about it from the intake ports point of view looking up the manifold... How many carb throats would it see with a single carb, and how many throats would it see with twin aisans? The same.

 

Twin aisans are overrated, unless you are after originality. The aisan carbs are the most unreliable part of a corolla.

Not so much originality, but period correct mods.

[Des]

Not so much originality, but period correct mods. More for looks than performance. Most likely will be going on a very mild 5k.

Edited September 7, 2010 by AE70

[Felix]

Not so much originality, but period correct mods.

 

If you want period correct, go a DCD Weber (off of 60's mk1 GT cortina). Heaps simpler, more tunable, more reliable, better fuel economy with more performance. :rolls: I've run twin aisans on my ke15, but a single DCD weber shits all over the aisans.

[Des]

You have giving me a lot to think about.

[camerondownunder88]

Felix you could just never tune them right :D

 

Des, my 2 cents...

 

After running twin carbies on the KE15 I have an original OLD set and a later KE50 set. Few differences are needle and seat. Early carbies run a smaller needle and seat and no kit I can find has the smaller needle and seat so parts can be hard for these suckers.

 

After getting mine tuned there awesome for reliability I find BUT after just putting in a cam there crap can't tune them ;) (well with out modding jets etc and I don't wanna do that)

 

If you also after the original look you will need to buy a set With original filter box and the special filters they need as In all my years I have owned and seen 1 original twin carbie KE1X series air filter box and it is on my sprinter most people dumped them back in the day so if your after originality will be HARD.

 

So I'm actually with Felix here even though your ride is VERY neat I think a single down draft webber might be the best for your case here.

 

Cameron

[Des]

If you want period correct, go a DCD Weber (off of 60's mk1 GT cortina). Heaps simpler, more tunable, more reliable, better fuel economy with more performance. :D I've run twin aisans on my ke15, but a single DCD weber shits all over the aisans.

I've been warned that DCD webers like to drop out the brass plugs and pour fuel out of the bottom ? Heard of this before Felix ?

[Felix]

I've been warned that DCD webers like to drop out the brass plugs and pour fuel out of the bottom ? Heard of this before Felix ?

 

Nope. Would have run a DCD for at least 6 years in my ke15.

 

I have however been stranded on the side of the road with twin aisans, when one of the carbs had a needle and seat stick open. Had fuel pouring out of the carb all over HOT extractors. Was the only time in about 20 years of driving KE corollas that I had to get a tow.

[Des]

Nope. Would have run a DCD for at least 6 years in my ke15.

 

I have however been stranded on the side of the road with twin aisans, when one of the carbs had a needle and seat stick open. Had fuel pouring out of the carb all over HOT extractors. Was the only time in about 20 years of driving KE corollas that I had to get a tow.

I haven't set my mind on anything yet but what about an IDA down draft weber ? Would need a custom manifold and may not fit under the bonnet though.

[Felix]

IDA would be cool for mid-top end. Probably would have to cut a hole in the bonnet though.