I have been thinking a lot about the cool little carb kit offered by rotary shack. The weber 34mm 1 barrel carb. It looks like the Weber 34 ICT. From what I've learned, I found that it gave them good fuel mileage, great low end and drivability, but it has a reduced top end.

So I was thinking about the idea of using a the Weber 32/36 DGV. It is a 2 bbl progressive carb.

From what i've read, it looks like it could flow about 350 cfm (flow is not everything, I know) I read that the weber 34 ICT flows 150 cfm.

Now this probably begs the question, "Why not just use the Nikki? Same concept"
I remember that Sterling once said that he can make a nikki give you 40 mpg.

And yeah, I see that. The modded nikki is better. But it IS a brand new carb available for under 200 dollars (which is cool), even through you would probably need some sort of adapter to make it work on the stock intake manifold (like the shack's little adapter)

Can anyone offer any insight?

Would this be feasible? offer any improvement over other options?

I see it as a way to maybe have the 40+ mpg claimed by the 34mm weber on a 12a, and not make the top end suck.

 

Ive spent a fair amount of time mulling over the sterling and im pretty sure im gonna get one but, as far as i know jetting it lean enough to produce that kind of gas mileage would make the combustion chamber very hot. Even then im not sure you would reach 40 and id be willing to bet the top end would suffer horrendously, that being said im not an expert on it and dont own one yet. just my 2 cents.

 

it sounds like a neat and novel idea, i have some spare manifolds here, and could easily make the adapter. but i don't have the carb, or money for one. so. you get the carb, and i can build the adapter. then we can try and get it running on your car?

 

I don't understand why people don't just disable the secondaries if they want good gas mileage along with mediocre performance. That should get you the same results. And then when you want performance, a simple adjustment to the linkage and you're all set to tear it up again.

I haven't nuetered my dog, and I'm not about to nueter my car either.


.

 

Good gas mileage is for Insights and Prius'. You can lean out the Nikki enough to get good mileage, just make sure you back off the timing as well. I've only tried a few times, but didn't bother backing off the timing and got a little detonation. Fortunately fuel mileage isn't all that important, so I just keep it rich.

 

you'd get better mileage with the sterling if you kept the vacuum secondaries.

you don't have to nuter it, that's the whole idea

40mpg is really outside the tuning realm of the carb anyway, going from 13:1 afr to 15:1 doesnt make a 20mpg change in mileage, its more like 2mpg

 

Yeah I see your points.

I really don't wanna neuter the car or anything. I am really thinking about the great ease of starting the car, driveability and low end that can be had from the nikki, or the 1 bbl carb. The fuel mileage would just be a bonus. And yeah 40 mpg would be shooting for the stars. Not likely.

Like I said, I know this begs the question, why not stick with the Nikki?

So basically I am looking at trying to come up with an idea for something to perform like a nikki. But it is a brand new unit that can be had for under $200 with parts that are easy to find.

I know that its about the same deal, So I'm hoping for this thread not to become a "just stay with the nikki, you moron!!!" kind of thread. I know very well that what I'm suggesting is a unit that has the same performance that the nikki can produce.


It flows about just as much as a stock nikki, maybe a bit more, but not as much as the sterling. So I don't see performance suffering a ton. It has a small barrel for high velocity air movement at cruising and part throttle, and a bigger one for acceleration. So it could perform like a stock nikki.

I guess what I'm asking is if it seems like this could work, if it would perform like i'm assuming it will, and ideas for trying to jet it correctly, from you carb masters out there.

 

Oh yeah Thanks Keeble. If this looks like it will work out, I'll definitely hit you up.

 

get a sterling, they claim to have sold several of these single barrels but I have yet to see positive testimonials. Now search sterling, you won't find anything negative about his work.

 

It looks like Keeble is the only one that read all of what what I wrote.

I KNOW THE NIKKI STERLING IS BETTER. That is not the point of this thread or this experiment. I am just looking at the weber as an alternative idea.

I appreciate all of your guys and your experience and knowledge. I really do. I don't mean to **** anyone off. I have been helped countless time by you guy's experience here.

I FULLY UNDERSTAND that the nikki will probably be cheaper in the end, and likely offer better performance, and maybe fuel mileage too. I'm just looking into the idea of the weber progressive to see what happens. I'm that sort of guy. I like to try new stuff to see how it works.

I actually talked to racerlinkfc here on the forum who owns one of the 34mm 1 bbl carbs, and he said that he thought it was great. Good fuel mileage with good driveability, good low and mid torque, and a reduced top end.

I was hoping to see if any of the weber guys could help with jetting. Or if anyone has any reasons that would make this particular carb, the 32 36 dgv, a bad or good idea for a stockport 12a.

I don't need to hear 100 time that the nikki will work out. I know this.

 

Nooo, "I" read your post, just the rotaryshack kit has so limited feedback!!

Being a Camden owner (I know a turbo is better, yeah, yeah) I understand the wanna be different idea. If you really want to be different, make a 3bbl off a 1982-1984 honda 1500 work, than you'll be original!

Of course he's gonna say that, "he works there!"


Okay, so we'll wait to say "I told you so" or better yet, I really hope you get original and creative and we can say "HOLY ****!" "YOU DID IT"

Not let's see you get original and prove us wrong.......

 

I have investigated this swap myself. The 32/36 DGV is the alternate carb that the SCCA specifies for carb'd Improved Touring racecars. This carb is also used on Formula Fords, Formula Continentals and Sports 2000 racecars.

After making some measurements, determining how the carb will have to be mounted on a stock manifold and speakling with a Formula Ford engine builder I determined that the swap was not a good idea.

While I have no flow numbers, when comparing the combined area of the venturis between a stock Niki and the 32/36DGV I determined that the Niki has more venturi area. Baically - the holes in the Niki are bigger than the holes in the Weber. While this may or may not equate to greater flow, installing a smaller carb on a car that spends most of it's time at WOT didn't seem like a good idea.

To install the Weber 32/36 it would have to turned 90 degrees so that the Primary barrel is over the primary ports in the intake manifold. The secondary barrel would be over the secondary ports. This would require a custom adapter but I think it is something I can make. The real issue here is that mounting the carb this way means that each barrel in the carb will be feeding both rotors. I have never seen a performance or OE carb setup on a rotary that has both rotors sharing a common chamber or plenum.

Finally I talked to an engine builder that is very familar with the 32/36 carb. We discussed the size of the venturis in the Niki and compared them to the weber. Given the numbers, it was his opinion there would be no perfomance gain with the Weber.

You might want to contact Pierce Manifolds - http://www.piercemanifolds.com/ - they sell 32/36 weber conversions for allot of cars. They do not offer a 32/36 conversion for the Rotary and maybe there is a reason for this? They so sell DCOE and IDA kits for 12A's and 13B's.

Good luck