ultimatejay

iTrader: (1)

No one has mentioned the 48ida. It has to be the easiest carb to tune. The jets come out in seconds- no fuel bowl to release and have fuel all over the place. It also has removable chokes- most if not all 4 barrel carbs don't. And they make great power and if tuned properly can be great on the street.

85rotarypower

Mikuni and Dellorto are the same way with the jets. My mikuni has 2 screws on the main jet cover that are removed then you have access to the 2 main jets and air bleeds I believe. Most 2 barrel carbs seem like their easy to tune, and I think thats because you don't have to worry about tuning the transition from 2 to 4 barrels or tuning for 2 sets of barrels that work on different sizes and air flow. Essentially, a progressive 4 barrel is twice the tuning of a 2 barrel. I say progressive 4 barrel cause you could make a 4 barrel's butterflies open all at the same time if the bores of the barrels were all the same.

Sterling

...which would render it about as useless on the street as a 2 bbl.

85rotarypower

2 barrels are useless on the street? Thats news to me cause last I heard, Mikuni's and dellortos are just as drivable as a good tuned holley or edelbrock.

Sterling

Then I guess IYO it was kinda stupid for Mazda to go and have Nikki make a four barrel carb for their rotary engines, huh? I mean, after all, a good two barrel is "just as driveable", right?

brandon davis

iTrader: (3)

Sterling could you tune a stock nikki to flow as much needed for a mildly streetported s5 motor?

Sterling

Not sure anyone could tune a stock Nikki for that.

85rotarypower

I'm not trying to say your wrong sterling. You are the carb expert after all. Your probably right. But I believe that drivability of a well tuned 2 barrel will be at least nearly as good on the street as a 4 barrel. Mazda went with what they thought would give the best drivability a carb could offer, and I agree that not much can touch it. I'm just saying that a 2 barrel is pretty good still on the street.

djessence

what does bbl stand for? (i know barrel but is that it or...?)

85rotarypower

bbl is short for for barrel as you guessed.

Sterling

Why? How? What's the point of a 4bbl then?

680RWHP12A

as far as maximun horsepower goes the nikki cant come close to a well prepped holley or a 48 2bbl carby, its just not big enough, for a ported motor that is..
the nikki will sufice a stock 12a though

ths thread isnt about that tho....

my vote is still for a sweet looking very tunable weber

680RWHP12A

better gas mileage

if nikki carbs were all that i think racingbeat would have used them to compete with as well as wouldnt mazda have used them too? i think not, they all used 2bbl webers to win races

the only poor saps that used the nikki carbs were the racers that had to ... rules suck!

Sterling

Well of course, Robert, whatever you say.
-You're the paying vendor...
If you have to **** on what I do to make your work stand out, I understand.Never mind the facts, no one will notice that you just referred to more than half the entire SCCA rotary crowd as "poor saps".

680RWHP12A

sterling, if you would kindly re-read my post then you would see i never mentioned my company but the founding father of rotary performance products, RACING BEAT!

i dont need to **** on what you do, you've done a great job of that yourself

oh and by poor saps i was not referring to thier financial status just the rules they have to go by.. oh and if your not familiar with scca, there are different classes in wich several classes do allow the use of weber carbs, the quicker classes that is

also the first star mazda formula cars use webers
the new pro cars have made the switch to efi, motec to be exact

dean7

LOL, who ever knew a thread about peoples personal prefrences might start some commotion? Before I go and **** you two guys off, I need to reiterate that you guys are alot knowledgable and I do admire your works.

4bbl>2bbl almost always for streetability... My old 48 ida and 44 mikkuni were just as dependable as my nikki for starting. Daily driving, just had to be more carfeull with the accelerator Prolly got a little less gas milage, but I was happy!

Also, us SCCA guys are poor saps! Heck i'm just doing SOLO II and a couple other local events and during my latest teardown and re-doing of the engine bay I said Duck it and went by my own rules. Ill prolly be in FP or what ever is above that not sure if an aluminum flywheel will bump me up, or a s4 engine, havent checked. Loved it about a decade ago, first race 83 gsl stock, and Im in CSP because of a crappy exhaust. There was a crx that was in my class, it's rear wheel was a foot in the air on corners $100 in mods vs over 10k

Ohh and I think that the Nikkis are a little more complicated, thats why we haven't seen to much "racing" applications. Paul Wall (Yaw) used to mod some, and apparently Sterling is also, haven't looked for/seen any numbers on the carbs, but im guessing they flow a bit more than stock

BTW the best carb for a 6 port is a 6bbl with 2 of the bbls as secondaries.. Right? lol

Siraniko

iTrader: (13)

nikki may be dependable but there is no comparison with a modified 48IDA. And rob is correct also. rule book calls for a nikki but a RX-2 carb is much better.

680RWHP12A

lots of mods for an rx2 carby wacky, the newbs dont know...shhhhhh

85rotarypower

The way sterling is defending the 4bbl makes me think we've offended him or something. Got a personal grudge against 2bbl carbs sterling? This is all just a personal opinion really. everyone has different tastes, and different opinions.

Sterling

No, it's not a personal grudge against 2 bbl carbs. It's a personal grudge against misimformation.
A 4 bbl carb that flows as much as it's 2 bbl equivalent, is going to have a wider range where the fuel mixture can be tailored perfectly. It's a simple fact of physics. Whether or not that carb allows for the fuel mixture to be tailored in such a manner is a different matter. But the FACT is, low velocity air flowing through two gapping venturis does not offer the benefits of that same volume of air flowing at much higher velocity through smaller primary venturis. The pressure differential to the main fuel circuit is much lower, and atomization at low RPMs is virtually nonexistent by comparison.
The open primary venturis of a Sterling Nikki (if the secondaries were kept shut) would flow their maximum at a velocity FOUR TIMES FASTER than the same amount going through a 48 IDA. It's simple math, people.
The physics behind the venturi; -the fluid dynamics of the venturi itself, illustrate the fact that the smallest diameter venturi you can possibly use for a given air flow will yield the highest pressure differential (vacuum signal to the main fuel circuit). OBVIOUSLY if the velocity of the incoming air is higher, the fuel will atomize better and stay suspended within the charge longer. This is not rocket science. All you have to do is some math, some research, and have the ability to question all the hype.

2bbl carbs will deliver just as high a peak power or high end as a comparably sized 4bbl in it's second stage- that's with the primaries and the secondaries all partially open to WOT. For anyone to say that a 2bbl beats a 4bbl just by it's nature, without making a very specific model to model comparison, is just plain idiotic, and downright misinformative.
A single gaping hole in a throttle body with only a minor bevel in it barely resembling a proper venturi will probably have enough pressure differential at it's apex to draw out fuel in enough quantity to make a usable mixture if 400 cfm is flowing through it. Drop the engine down to 7K RPM, and now it's nothing but...
- a gapping hole.

My problem is that people enter into these types of discussions and inject there creamy twinky filling about which type of carburetor is best, and they know absolutely nothing about how a carburetor actually works. If they did, then they wouldn't say something so idiotic as to suggest that both a 4 bbl & a 2 bbl carb of equal flow capability aren't both equally capable of making the same peak power on an engine. ANYTHING, even just a manifold with a fuel jet and reservoir attached to it, could be tuned to deliver "peak power"! People are drawn to Peak Power numbers & bling, and that's exactly what marketers of performance products set out to appeal to; ignorant people who see a big number and some bling. -That's all fine a good if that's what you want, but don't confuse those two things with "performance", because for even considering the vague generality of how it's used, only one of those things plays a small part in the definition of the word, folks.

Where allowed by race sanctioning bodies, the stock Nikki has had a history of being replaced by two bbl carbs. OF COURSE THEY WERE! WTF?! The stock Nikki sucks for flow, the manifold is a joke as far as flow, and the RB Holley setup costs ridiculous money. But just what in the hell did they need any power under 3800 RPMs for anyway? lol
Robert blows through his Webers. That's great. They look great and perform really well. I've NEVER seen anybody complain that they weren't anything less than ecstatic about the results. (We may be ********* to each other, but there's no denying he's good at what he does.) But just because Robert uses Webers in his showcase quality blow through applications, it does NOT make that carb conducive to performing the same way under the pressure of the open, starry sky, because adding boost changes the entire dynamics of the flow through the carburetor. There's no doubt in my mind that he's nailed down the mixture low in the flow. But again, the application, folks... Not NA. Once you boost the carb, toss the flow rating of the carb right out the window. You might as well take the carb to a different planet with a different atmosphere, because it makes no difference how well it flowed @ 14.7 psi.

As for "personal opinion", sure, everyone's entitled to their opinion regarding style, taste, priorities, whatever. But from a purely scientific approach, some of these "opinions" that are wielded around like they are "facts" taint the whole conversation / debate / argument, and supply inconclusive and conflicting bullshit advice for newcomers. And the reality for me is that it's the newcomers' budget that I can appeal to with what I make. If I don't come into these threads and debunk a lot of the **** I see, then what chance do I have of selling anything? The way I see it, I don't need to push my product at all. I just have to push the facts, and help educate people that don't know wtf they're doing. But it never ceases to amaze me how many people who are not newcomers that really don't seem to know what they're talking about when it comes to carburetors. What really ticks me off is when they insist that they do, and continue to spew out bullshit.

I get tired of dealing with people that haven't done their homework. I get tired of people who can't separate the "bling factor" from performance. I turn away customers who I feel aren't serious enough. I sell to serious enthusiasts, and only to those who are prepared to accept the fact that they will need to tune the carburetor that I build for them themselves, according to their individual driving habits and techniques in order for them to reap the full performance potential of the carburetor setup. I don't do this to be "Captain Carby Crusader", I do this as a measure of self preservation; so I don't go nuts, because when I sell a carb, I also sell a commitment to help get that person up & running, AND dialed in right to whatever compromise between mileage and performance they may require, if any, and together we take into consideration the application and their driving style. And if I fail at that, they have 30 days to send it right on back, so I really NEED to get them set up properly, and that's a difficult enough tast because there are a LOT of different driving styles.

How come I never see anyone else talking about that? How come when someone says, "Which carb should I get?", I never, ever see anyone respond with, "Well, what kind of driving do you do?", or "How do you drive your car?"?
Once in a while I'll see the parroted, but sensible response, "How much do want to spend?". Yet I always see this CRUCIAL, CRUCIAL variable overlooked by everyone when dulling out carb selection advice.

I can sit here all morning and toss a whole bunch of numbers and theory and other flow bullshit out into this thread, but no one needs to hold my hand to work the Google button & a calculator. None of it is anything anyone can't figure out on their own. The fact is, dyno sheets talk, and bullshit walks and I realize this 100%. I can't prove anything by pitting one carb up against another because I don't have the cumulated data, and even if I could compile it, the variables in all of the various sources would scrap it. Even I concede that fact. I sure as hell can't take the "Pepsi Challenge" with my Sterling Nikki right now... -at least not yet. Hopefully by the end of this summer I will have the engines and testing equipment I need to make a genuine clinical side by side comparison of carburetors. More realistically it'll be another year.
But in the mean time, as long as I'm a presence here on this forum, where carburetors are concerned, when I see someone post their opinion as if it's fact, I'm gonna call 'em on it. Simple as that.

rotaryB-2000

Sterling....Their new setup is more responsive than any holley, delorodo or weber.

synergy7

iTrader: (20)

Oh!! Thats funny I dont think we've meet, I usually remember an *******.
It's not OK that you know nothing about me and choose to call me out my name.

I have first hand exp with Holley carbs, Nikki, Dellorto 48 IDA, Mikuni, dual Weber 36, and Weber 48's down draft, HOWEVER for many of readers of the forum my exp dose not mount to a hill of beans so rather than waste my breath I directed people to an "independent" party which has more credibility than all of my years of exp can give to present company. I hoped that people of average "intelligence" could read between the lines, but there is always at least one dumb ***...

Since I have to S..P..E..L..L it out:

By driveablity I meant powerband and gas mileage ("efficiency") Peak Power was mentioned because that is what alot of these guy want to hear about, it gets peoples attention.


This is why I dont post often there is always one guy who whats to be the crude guru

Sterling

Oh, hey man, sorry, my bad. It's just that from your original post;-it seemed as though you thought you were just gonna waltz in here and trump the combined decades of experience with a magazine article and a Holley advertisement. You pretty much said, definitively, without a doubt, supplying your uber-proof even, that "HOLLEY" was "the best one for a Rotary", and you were gonna single-handedly "put this to bed forever".
I guess I took you the wrong way. I mistook you for a complete and utter moron who knows nothing about carburetors and air flow dynamics, when in fact, -as proven by your post, after having reread it, clearly you're not only an expert on the subject, you actually know everyfuckingthing about it!

-Again, my bad...

Look Beavis, I dunno who you are or what your years of experience amounts to, but for anyone who knows anything about how carbs actually work inside, to see someone adamantly push a BRAND of carburetor as the unequivocal "best carb for a Rotary", without taking into consideration any variables whatsoever, including engine size, engine porting, manifold flow, carb size, secondary timing, or carb modifications, (etc, etc...), they'll be seen as a know-nothing idiot.
YOU made yourself look like a teen-ager with Holley stickers all over your car who works as an under appreciated employee at a speed shop with higher aspirations than cleaning wheels. Just the generality of what you posted gave you away as someone who doesn't know wtf they're talking about, as far as I'm concerned. Tossing a magazine article out as your source for information pretty much capped it for me.

Love the avatar. Why don't you get on that Big Wheel and ride off, now.

84stock

iTrader: (5)

Wow, being 45 and having a collection and having just added a sweet numbers matching factory holley spreadbore to test on my camden I thought I would chime in. I've met many that will claim holley or carter are **** etc etc etc. The key to "ANY" carb is proper size selection and tuning. Example, I have an edelbrock 650 which is the most streetable of all my carbs, I have a demon 650 blower carb which I couldn't get dialed in worth **** on my streetport but is dialed in well on my bridgeport. And, I have a holley 850 double pumper which screams on topend and holds boost longer for better topend hp on my setup, but isn't worth **** as a daily driver carb because the primaries at too big and you're still in the idle circuit on cruise. Tough thing with my setup is that most north american carbs are for v8's with a good torque curve and a narrow power band. Take a 396 for instance, good off idle torque and a powerband that runs from 300-6500 rpm. Compare that to my supercharged 1/2 bridgeport, the blower brings the powerband in early compared to a turbo or n/a, So "my" powerband can start at about 2500 rpm and "can" go past 8000 if you things dialed in right. Hence, fuel injection and a standalone, but $$$$$ are a factor and I am an old dog who is more familiar with carbs. My rare find, an 800 cfm double pumper, small primaries for driveability and huge secondaries to take advantage of the topend potential of the bridgeport. Before you say "too big", I've already run the 850 and with the blower your boost falls off sooner with a small carb and my engine gets pretty thirsty for flow above 6500 rpm. So we shall see. If I was running a stock or street port n/a car, "I" would make one of 2 choices, an edelbrock 500 thunder series or a sterling and that's it. Sure a sidedraft with functioning 6 ports would be nice, but that's a whole new learning curve since I am unfamiliar with them.

84stock

iTrader: (5)

ooooops, 396 powerband should've read "3000" to 6500 rpm. Need to proof read "before" submitting...