QUAD Motorcycle Carbs

[Zufer]

I have been looking into this a bit and was wondering if anyone else had thought about it. I think that putting 4 mikuni's such as these http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=35597&item=2490062956&rd=1 or many of the others that show up on ebay would be sweet. Kinda like an individual throttle body set up. It seems like it is a lot like dual webers, except as far as i can tell mixtures are easily adjustable via several needle valves.
Just wondering if anyone can see any problem with this or if anyone has worked with these carbs before and can offer any suggestions. Also, would 38 mm carbs be sufficient.

Thanks for any input

[smufguy]

well one thing that you and i know is that it can be done, but would involve a shit load of work. I dont know if there is any emission probs in Washington (dont know why there would be any) then u would have a tougher task.

WEll if u want brute power, this is the way to go. as in ITBs. but there are a lot of things to be custom made and i would say to start off, get urself a new manifold gasket and a thich piece of aluminum. or even u can try adapting a spare stock carb manifold to recieve these carbs. I have seen one on the CBX, but not very intrigued by it. So think about the money and time vs power for this ITB set up or the dual webber set up.

This territory is not new, i have come across few threads about it. so hit the search and see what you find. talk to carb gods like Andy (pheydux) or Mike (A20A1) and see their input.

[A20A1]

38 isn't that bad, you'd get a more resopnsive throttle then say a 45 dcoes but then you'd probably suffer some where later on as to the maximum amount of power you can get.


There is limitations to the choke / throttle size of the carbs but no limitations to ITB's bore since it doesn't rely on pressure drop.

I just like carbs casue you dump the ecu mess.

[Zufer]

i like carbs as well, i also am starting with a carb so i think i want to stay that way, right now i have a weber 32/36 which seems ok but i want something better, i also plan on getting a cam and header asap so once that happens i will hopefully be able to upgrade the carb system. The car sees mainly street driving and auto-x so throttle response is important to me more than wild horsepower numbers.

[Immeraufdemhund]

i was looking at those carbs and i dont think it would be all that terrible. What i would do is get a stock manifold. cut off the runners and keep the base. Get or find gaskets for the katana carbs and trace those on the manifold. then dremel away to make the hole match up to the new carbs. I dont know though if you are able to seperate or shrink the distance on those carbs...that would take some interesting machining or if they happen to line up even better.

[Zufer]

My accord started and ran today on a rack of 4 34mm mikuni carburetors. First impressions are pretty good. It needs some tuning but I think it will all pull through. I built the manifold myself its not pretty but it is functional. The only thing i have left to build is a bracket to hold my throttle cable so that it doesn't hit the hood. And i have to get a cable to run the high idle lever. Here are some pictures. Questions and comments welcome.

http://www.imagestation.com/picture/sraid220/p88812eea341657040cf40d64c62e530f/ebc11465.jpg
http://www.imagestation.com/picture/sraid220/p57d036791a23134b4c29708e9cbed69c/ebc11444.jpg
http://www.imagestation.com/picture/sraid220/p4355aef298107ff6b1620d2801b6a8f0/ebc11427.jpg
http://www.imagestation.com/picture/sraid220/p9416f0c683c81062204f004ae83e2f5c/ebc1140e.jpg
http://www.imagestation.com/picture/sraid220/p2d2d0b1fabc756e34c7d86c340f108b5/ebc113f8.jpg
http://www.imagestation.com/picture/sraid220/p5e472981f2ce6a7297b145490ea198e1/ebc113db.jpg

[A18A]

lol i was just thinking bout quad carbs yesterday :D

looks cool!! 1 carb per cylinder :D :o :bow:

[Zufer]

never mind i fixed it

[MessyHonda]

looks good was your car cabrd or fuel injected...im only asking cuz of the valve cover and you dont have the damn vac box...it clears the engine bay and it makes it look clean...just scrub that puppy down and it will look hot

[Zufer]

the car was carbed. The valve cover is off a prelude(so FI engine). And before these i had a weber on there so i had ditched the vacuum box a long time ago. And you are correct my engine bay does need a good cleaning. Hopefully this winter it'll happen.

[A18A]

i was wondering the same thing, but he does say it's a LX, and with a custom quad carb setup like that, why would you wanna put a vacuum box back on there? lol, i noticed the valve cover breather was on the other side too.

btw, were/what did the carbs come from??

[bobafett]

you cant run motorcycle carbs on a 3g! ;-)

glad it runs man... just gotta get that bitch tuned, and then we will see what the 282 is really capable of!

[AccordEpicenter]

i cant wait to see it set up and running good, carbs can make a serious difference

[Zufer]

the carbs are from a 88 honda shadow i believe... i bought them off ebay based on the size, which i guessed after reading about head flow, carb flow, and all the weber threads

[Justin86]

Yes I want to see a big cam in there!

[ghettogeddy]

thats kinda like having itb's right

[gfrg88]

fuk yeah!!! 282 cam in that bitch!!! :thumbup:

[ilikevtecs]

god damn, almost wants to make me stay carbed!

[Hash_man_Se_i]

thats a pretty cool setup. Props for the work... are you not running filters on them right now?

[Zufer]

thats for all the good comments. The 282 was sweet with my weber so i can only imagine it to be great with these witha good tune. The manifold was originally a 86/87 FI accord manifold that i choped to flange off and machined it flat and yes i used the injector ports for a vacuum log.

[thegreatdane]

Isnt 34mm pretty small for a 2.0L?

[rjudgey]

Oh at last someone finally listened to what i was saying a bit the bullit!!! I'm so pleased man glad to see you running!!!

What you need to do next though i believe the Mikunis use weber jets so you might be able to tune them yourself best bet is to maybe take it to a bike shop to have a bash at tuning.

But to be honest the carb size seehow you get on personally on a A20 head there a bit small especially with headwork and header, might want to find some Honda fireblade carbs they are 38mm and would work much better. But anywasy still much better than one Weber 38/38 and the inlet manifold length is great longer the better for really good torque and fuel mixture, next thing might be airbox with a hood scoop straight into the air box over the top get some ram air effect going on.

[2oodoor]

looks awesome, great r&d....I hope they are big enough not to lean out at an extended runout, cause it definatley will be flowing like a mugggg

[Sabz5150]

Oooooooohh I want to go ITBs so bad!

Excellent work, and vid/audio of engine running :)

[shepherd79]

well i want to start with CONGRATS!!!!!
but i have a few questions:
1. is that JBweld you used to seal all the wholes?
2. Those runners are they PVC plastic?
3. why did you make them so long?
4. are you gong to use velocity stacks? You should because it will help ya with a flow, but the way it is setup now, i don' think you have enough room for them.
5. are you planning on making better / custom manifold?
Overall I give you two thumps up. Nice Job.

[Sporno]

nice nice ... its sorta like ITB's , but how are you gonna tune it?

[Zufer]

again thanks for all the positive support. Now to answer a bunch of questions.
Carb sizing: When i was trying to select a carburetor i went through the weber thread in R and D and a couple of the guys that had been running A20's on webers said they were using 30mm and 32mm chokes. So i figured that with the big cam a 34mm would probably suffice. I also had throttle response as my top priority so i didn't wanna go to big.
As far as tuning goes i plan to do it myself. I have access to a wideband O2 sensor and tuned my own weber so i think i should be able to tune this setup as well.
Yes that is jb weld.... this is the first time i'd welded aluminum so i had some holes in my welding. It is also a combination of metal putty and jb weld holding the vacuum log on. Eventually i will probably go through and build a nicer manifold. But for right now this works and i didn't want to go through the trouble and time of making a nice manifold to realize afterwards that the carbs were not sized properly or soemthing and have to scrap it all. And this is a function over fashion car so i am not bothered by the less than perfect manifold. This manifold is not PVC but i did give that a try i just couldn't find an epoxy that would hold the runners together once it warmed up. So i've actualy had the car running twice before this but each time the manifold fell apart. Woooops.
I made the manifold long trying to get more low end torque because the 282 cam destroyed the torque down low.
Velocity stacks would be cool but as you said i don't know if they'll fit between the firewall and the carbs. And my carbs already have a velocity stack shape built into the inlets. They are a 50mm inlet that necks down to 34mm. And rjudgey nailed the hood scoop idea. I think that i am going to get one this winter and then make a rain shield of some sort for whatever filtering system i decide to run.

[Toneloc5145]

Man this is sick. 4 carbs. I've got to see a video of this. Props to you for staying true to carbs.

[Cheeseburger]

dam thats sick

[BITESIZE]

Does it run good?

[Cheeseburger]

more pics would be nice, and i wonder how much it would put out in a dyno run......

[mkymonkey]

wow that looks pretty cool, i WOULD also like to see more pics of course. good luck with the tune and awesome job bro

[rjudgey]

Only reason why i'm questioning the carb size is i've tried choke sizes from 36-42mm and the best ones work at 38-42mm most power from 40-42mm difference is next to nothing on these though maybe a 2-3bhp but huge difference from 34-38mm found the engine just struggled to rev and lack lots of power. And this is on a A18 which are normally not reknowned for high flow or lots of bhp but do produce excellent low end torque due to the curvy inlet ports and the curvy weber manifolds. MOST power i've had out of A18 was 186bhp with a bif valve conversion and a ton load of extensive headwork, the exhaust cast header could have been ditched but even with a Pacesetter would probably have only gained a few bhp as the cast one was heavily moddified.
The bore spacing on the bike carsb are pretty much all the same so you could most likely try carbs from another bike with bigger bores maybe.

But anyways you may be okay on this if you want good low end you should get it but i wouldn't expect it to rev much past 6-6.5k rpm might be more prudent to use a lower spec camshaft like a 270-275 degree with 10mm lift give you bit more low end and you won't be wasting top end with the smaller carbs a 282 is normally good for 8k but you'll need bike carbs with at least 38mm to produce power that high up.

[Zufer]

as of right now my engine has 195k on it so i'm not really planning on reving much past 6500 anyway. And i have no plans of doing an extensive rebuilt. Probably just a refresh next winter. So if i can get a good tune of to 6.5k i'll be happy for now. We shall see. You might be right

[1320boy]

You gotta put a how to thread on this. I was thinking about that for a while but some ppl told me that would be too much time, money, effort, and a waste. So what do you say???

[Cheeseburger]

more pics!!!!!

[MessyHonda]

does it sound better?

[AccordEpicenter]

whats wrong with JB weld? I bet that manifold will work just fine

[EricW]

Nice work. Have you thought about adding a support under the manifold to help support it, since the runners look long?

[bobafett]

haha i bet there is less than $100 into this project so far... how much did you pay for the carbs and the aluminum?

[AccordEpicenter]

see it doesnt have to be pretty to be functional

[87preludeA20A3]

Sweetness, you have to do a dyno run with those... Great work.

[Zufer]

so far for the setup on that car i'm right around 100 dollars. I paid like 40 shipped for the carbs and about 45 for the aluminum. But i have a bit of extra tubing. And i probably have 15 dollars into odds and ends. As of right now i can't really give a good opinion because I went from an awesome tune on a weber to a terrible tune. But hopefully this weekend i'll get that sorted out. I did drive it today which was sweet but hard to tell how it was actually gonna perform. I did think about running a support but i don't think i'll need it. The welds should be plenty strong to hold everything.

[Cheeseburger]

wow thats not bad! sweet buy maing!

[Civic Accord Honda]

that is pimp
and i love the color with the goldish rims it looks hot

[shepherd79]

i have to agree with Eric, you should consider support under those carbs. You can't just rely on welds. vibration and stress will crack them for sure.

[Zufer]

I might but a support under it at somepoint but right now i'm just trying to get it back on the road

[2oodoor]

i have to agree with Eric, you should consider support under those carbs. You can't just rely on welds. vibration and stress will crack them for sure.
A20, no balance shaft, even the sturdy factory manifold uses supports, that should be figured in the mix
An idea to diguise any uglyness is foil furnace tape, just an idea. I used it on my adapter plates, I used epoxy around them to they dont tend to shake loose the plate screws, it looked bad but worked good, so I used a small strip of that foil all around the adapter plate after I trimmed off the goopped metal epoxy,it still looks nawigged, but better than goop.

[speedpenguin]

That's great! I want to see dyno results now!

[gfrg88]

so when do you plan on dyno'ing it???

[Zufer]

right now i'm still working on getting a base tune on it. Hopefully this week but i have finals to work around. So sometime this summer probably when i have a job again and can afford dyno time. I know you are all waiting to see it. Again thanks for all the comments. And i do plan on making a support bracket... But right now thats not the focus i wanna have a totally drivable car again first.

[Zufer]

just a quick update on a break from workin on the car. It now starts everytime, and has a decent power band. Oh how i love being able to tune my own carbs.

[A18A]

have you taken it for a good drive yet?

[Zufer]

not really just been cruising it around the neightbor hood but soon i'll go for a drive that actually checks out the power

[A18A]

cool :D would u be able to get vids?

[Zufer]

i'll get some vids soon it still needs some work but it is running great.

[Justin86]

ha ha sweet! I can't wait to see this in person.

[2oodoor]

i'll get some vids soon it still needs some work but it is running great.
I want to hear it running out, that would have to be a wicked (endearing term) sound, probably like sounds like three cars running.

[SQ is the SQUAD]

have you noticed a difference in the driving yet?

[lostforawhile]

i have to agree with Eric, you should consider support under those carbs. You can't just rely on welds. vibration and stress will crack them for sure.what did you do with the factory supports? just cut an aluminum bar to fit all the way across your manifold,drill and tap it to accept the factory support bars,and weld it to your manifold at four points. it already fits to the block. thats what I'm going to do with my SU manifold. make it nice and sturdy like factory and you'll never have to worry about it again. what angle did you machine your tubes off to? I measured from the original carb mounting plate to the angle where it goes to the head with a machinists protractor,got 15 degrees,in other words I have to clamp the original piece of manifold in the mill,tilt the head 15 degrees and mill it off,then the carbs will sit level on the engine.

[Zufer]

mine don't have any angle on them so they are a straight shot to the head. I figured with a motorcycle carburetor that is designed to deal with wheelstands and the forces on a bike that the angle wasn't outside the range of normal operation.

I just got back from a mountain pass drive and so far i've decided i still need more fuel but the mid range feels great... the low and the top are spotty so just need some more tuning... But it does sound pretty sweet

[2oodoor]

mine don't have any angle on them so they are a straight shot to the head. I figured with a motorcycle carburetor that is designed to deal with wheelstands and the forces on a bike that the angle wasn't outside the range of normal operation.

I just got back from a mountain pass drive and so far i've decided i still need more fuel but the mid range feels great... the low and the top are spotty so just need some more tuning... But it does sound pretty sweet
Awesome, I dont know if you thought of it but you should consider an exhaust temp guage to keep up with the tune. If you havent already. When your trying to get the best of both worlds (in many aspects) it helps to have another fail safe monitor for peace of mind. Even then with four carbs you cant monitor each cylinder for lean condition from the "cockpit" without some extravigante' intrumentatio'neon

[Zufer]

i was able to get a wideband today and get a much better tune on it. My instincts were correct, it was running a bit lean. Now the power is nice and even and acceleration is smooth. Rjudgey might still be correct in saying i need a slightly bigger carb maybe a 38mm. But its kinda hard to tell. So far i've done a 3rd gear pull and it was seam better than the weber i had on there. The only spot that the tune isn't good is from idle til the cam starts kickin in... so about 3500. It runs a bit lean through this section. I believe that this can be cure with adjustment of the needle jet... But i don't really know what to do with it. If anyone has some insight that would be good.

[lostforawhile]

mine don't have any angle on them so they are a straight shot to the head. I figured with a motorcycle carburetor that is designed to deal with wheelstands and the forces on a bike that the angle wasn't outside the range of normal operation.

I just got back from a mountain pass drive and so far i've decided i still need more fuel but the mid range feels great... the low and the top are spotty so just need some more tuning... But it does sound pretty sweetwhat I was talking about with the angle,is that when th car is sitting level,the carbs should also be level,this is to set your tuning baseline,if the carbs are at an extreme angle,your level in your float bowls will be screwy and it can cause all kinds of wierd problems. this is true with any carb,downdraft or sidedraft. you generally want the floatbowl to be level. the carbs ae going to change angles in operation but you still want to set from a baseline. for example, if you ran tubes straight from the original flange,the carbs will already be off 15 degrees add a 15 degree grade and they are off 30 degrees. that a lot.

[rjudgey]

doens't it depend on what type of carb most bike carbs aren't mounted onto a bike totally flat? so may not be effect like Webers, and others for having too exteme an angle? Not 100% sure though.

[Zufer]

i realize what you are talking about lostforawhile... but if you think about the forces a bike carb sees compared to what it is seeing on an accord i think that the 15 degree angle i have is fine. Also after driving in up and down some hills with the wideband it didn't seem to be effected by inclines either way.

After another freeway trip i can say that the carbs give a very smooth power curve... But you can really feel where there cam isn't in tune at all. Basically 5th gear is useless on a hill unless the revs are about 3500. Some of this i believe is the slight lean spot that i need to take care of.

rjudgey: How does the need get used for tuning? I get that it is supposed to be what blends the pilot jet to the main jet. And i read somewhere that tuning is done by adjusting the height of it... But i can't really tell how it changes.

[shepherd79]

do you know the model of your carbs?

[smufguy]

That is hot as hell. I like it very much nice jobs.

[Zufer]

they are a Mikuni 34mm CV carb. I believe they came off a mid-late 80's honda 750 shadow. Other than that i couldn't tell you. I am really thinking about trying to find some 36 or 38mm carbs this summer to give them a try although as of now i haven't felt like the carb flow was limiting power but its worth a try.

[rjudgey]

Not sure to behonest not great with bike carbs, i know that some mikunis can be rejetted using Weber main jets so might be worth looking at that see if you can take one apart and see whats inside. But normally most people reem the needles a little bit at a time untill they get what they want. I think you might have to check out some bike tuning forums that might help or have a word with a bike tuner thats nearby maybe he'll suggest something or mght be able to help you out for a small fee.

[lostforawhile]

hey I know you are checking the air/fuel ratio as you drive but are you monitoring your fuel pressure also? the factory fuel pumps on these cars suck,they will hardly keep up with one carb,let alone four. you might be leaning out because of a drop in fuel pressure,also you will need a pump that can flow more GPM to keep four fuel bowls filled. I believe those carbs were originally gravity fed? or did that bike have a mechanical pump on the engine? if you upgrade the pump you will need a regulator for sure, I would guess maby 2 psi on those carbs. the FPR on my car is a low pressure one from holley,it will adjust from 1.5 to 5 psi. thats the type of regulator you need for those bike carbs. they need very low pressure. a better fuel pump will flow a higher rate of fuel and you won't have to worry about lean out. I'm going to be running a holley blue pump on mine when the conversion is done. here is the latest on mine http://www.3geez.com/forum/showthread.php?t=56803

[shepherd79]

upgrading fuel pump would make a lot of diff. just remember you need volume not the pressure.

a few website that may help with tunning
http://www.factorypro.com/products/Jets,%20Mikuni,%20buy.htm
http://www.factorypro.com/tech_tuning_procedures/tuning_carbtune,CV,lower_rpm_engines.html
http://www.carbparts.com/mikuni/mikuni_tuning_info.htm
http://www.factorypro.com/tech/carbtun.html
http://www.xs11.com/tips/offsite.shtml

[lostforawhile]

here is the regulator you need,this is the same one I'm running,this will handle plenty of fuel flow at the correct pressure you need. what you could do is run two aluminum t fittings off the regulator,then you have a line for each carb. or make yourself some sort of fuel rail. just don't make it out of pcv LOL just kidding. http://store.summitracing.com/partdetail.asp?autofilter=1&part=HLY%2D12%2D804&N=700+115&autoview=sku

[Zufer]

i don't think fueling is the problem because it runs right around 13:1 afr all the way to 7k... But from 2k to 3k its just a tad lean at all throttle positions. This i believe is due to the cam not pulling enough vacuum to get the required fuel into the engine. I am running a delta 282, and after the dyno sheets from openloop i am thinking i wanna run something a bit milder. If i start to have fueling issues i'll worry about it then.

[shepherd79]

oh, i see. well i can see how wild grind will cut into low rpm.
yeah try delta 272 and see what happens.

[Zufer]

so a little update... two of the carbs weren't working right and the vacuum control pistons weren't opening all the way. So i got that fixed and can now say that i like these carbs a lot better than the weber. There is equal if not more power. Definitely some more torque through the mid range. And power delivery is very smooth. It also drives more like and efi car where you can just mash the gas and it doesn't hesitate or anything. So now i just need to figure out an air filter and do a little clean up on the manifold and the project will be done.

Ok for anyone thinking of doin this..... make sure you realize the extent of what you are doin.... It took me a good couple weeks of working on it fairly regularly to get the car to start on its own and actually be drivable. This is not a mod for the amatuer mechanic or someone who has never tuned a carburetor before. However for those who feel they can undertake it i think it is very worth while. But a time slip and a dyno this summer will show me how worth while.

[bobafett]

you need a baseline with your weber now though. :)

[Zufer]

didn't someone baseline an accord quite a while ago stock... and see like 85 whp's. But you are right a comparison between a weber and these would be cool... Maybe if i feel really motivated this summer! And rich!!!! that takes a bit of dyno time to compare both

[lostforawhile]

so a little update... two of the carbs weren't working right and the vacuum control pistons weren't opening all the way. So i got that fixed and can now say that i like these carbs a lot better than the weber. There is equal if not more power. Definitely some more torque through the mid range. And power delivery is very smooth. It also drives more like and efi car where you can just mash the gas and it doesn't hesitate or anything. So now i just need to figure out an air filter and do a little clean up on the manifold and the project will be done.
Ok for anyone thinking of doin this..... make sure you realize the extent of what you are doin.... It took me a good couple weeks of working on it fairly regularly to get the car to start on its own and actually be drivable. This is not a mod for the amatuer mechanic or someone who has never tuned a carburetor before. However for those who feel they can undertake it i think it is very worth while. But a time slip and a dyno this summer will show me how worth while.are your carbs slide carbs or based on the variable venturi(su) design? a lot of the japanese bike manufacturers abondoned the old slide carb design for the su design carb on bikes. they offer much better mixture control and better driveability at low rpms. the two designs look the same,but on a slide carb the throttle directly controls the piston,but on the variable venturi design the piston is controlled by airflow through the throttle bore and the throtle has no direct connection to it. how it works is that the top of the piston has a passage to vacccume in the throttle bore,when the throtle plates open,this vaccume causes a low pressure area above the piston,causing it to rise,this exposes the metering needle and allows more fuel to enter the throttle bore. when the vaccume stabilizes the piston comes back down lowering the needle and allowing less fuel to enter the bore. it's very simple and is very accurate. the SU carbs were the original carb to do this,and the design was copied many times over the years. a lot of these copies were on bikes. primarily because it worked so well and it was extremly simple.

[Zufer]

yes they are the variable venturi type. What part of my comment was that a response to?

[lostforawhile]

yes they are the variable venturi type. What part of my comment was that a response to?
oh you said they hadn't been working right,I was just wondering what kind of carbs you had been using,I am doing a project sort of like this right now also,it's interesting to compare the different carb projects going on. who needs fuel injection? LOL.

[MessyHonda]

who needs fuel injection? LOL.

i do...but is still got carb love as long as it runs right

[teck]

sexy!. you pulled those off an older model CBR didnt you?? my friend has an 80s CBR and the cards are exactly the same

[Zufer]

I believe they are off a 1986 shadow, but i got them from a guy on ebay so i don't know for sure

[teck]

ahh

[Zufer]

http://photos-508.ak.facebook.com/photos-ak-sf2p/v74/123/38/29300111/n29300111_30602508_5362.jpg
http://photos-509.ak.facebook.com/photos-ak-sf2p/v74/123/38/29300111/n29300111_30602509_5608.jpg
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http://photos-512.ak.facebook.com/photos-ak-sf2p/v74/123/38/29300111/n29300111_30602512_6343.jpg
http://photos-514.ak.facebook.com/photos-ak-sf2p/v74/123/38/29300111/n29300111_30602514_6824.jpg
http://photos-516.ak.facebook.com/photos-ak-sf2p/v74/123/38/29300111/n29300111_30602516_7324.jpg
http://photos-518.ak.facebook.com/photos-ak-sf2p/v74/123/38/29300111/n29300111_30602518_7806.jpg
Enjoy, comments are welcome.

[MessyHonda]

very nice.

[wprocomp]

your cars about to ambushed by the grass lol

[87lxiaccord]

Does it run? Where'd you get that strut bar?

[russiankid]

Are you running the stock fuel pump to handle those? Anyways vids!!

[snoopyloopy]

hothothot. that's pure sex right there. how does it run? any power numbers, or at least estimates?

[Zufer]

it runs, still needs a little bit of tuning, but runs amazing, yep stock fuel pump. As far as power, well it was noticably better than a really well tuned weber 32/36. And it is extremely smooth power.
and the strut bar is a shucks civic bar that i redrilled the holes on and flattened out the bends in the bar

[Legend_master]

That is awsome dude, and I bet tuning 4 different carbs is a bitch :gun: .

[A18A]

thats sexy :bow:

[che3wy]

wow nice. i say for future reference turn down the white balance there's a bit of overexposer making the picture washed out. sorry a bit of my photography kicking in. love the carbs man

[HondaBoy]

looks pretty cool. would it be possible for you to make some sort of video? i'd love to see a vid under the hood and then while driving.

[guaynabo89]

good work looks really nice.

I have one question though.... Why not leave them individual and run some trumpets with foam filters on them instead of tying it into that plenum? Did you make tha too?

[russiankid]

good work looks really nice.
I have one question though.... Why not leave them individual and run some trumpets with foam filters on them instead of tying it into that plenum? Did you make tha too?
I was thinking the same thing at first, but couldn't word it correctly.

[skycam_313]

:bow: NICE.

[LX-incredible]

Cool.

[Zufer]

to be honest the reason i went with the plenum was i had all the stuff to make it and i am extremely broke at the moment. Also i gain the benefit of cold air, which i would have lacked with velocity stacks and foam filters as they would have been right behind the engine and above the exhaust. And yes all the fabrication and welding was done by myself.

Thank you all for the great comments, i'll try to get a vid of it running sometime, but i don't know how much how well you will be able to see anything if i driving, but i can get a free reving vid soon.

[87lxiaccord]

You should dyno it!

[bushbean]

What is the reasoning behind having four little carbs instead one big azz one?

[Legend_master]

What is the reasoning behind having four little carbs instead one big azz one?


It's like EFI before computers were around.

[Zufer]

the idea behind 4 little carbs is that each cylinder gets the precise amount of air and fuel as opposed to a single carb which is a generic tune so the cylinder just get whatever mixture there is in the plenum when they are sucking. Also 4 carbs give better response which was the main goal. Because i autocross and track my car i am not really worried about peak horsepower and more worried about a flat torqure curve, this was the best way to do that NA.
and yes i plan on dynoing it. But before i do i have a teg tranny and a lightened flywheel to put in, and some porting and tuning to do.

[2ndGenGuy]

Sweet setup man! You should PM me next time you head to an autocross. I do some up here, but I would totally drive to Portland for a chance to go with another Accord. :)

[Zufer]

ya i will for sure let you know when i'm gonna be running, i don't know how much autocross i'll be doin but i definitely am gonna get to a couple trackdays in august, well atleast thats the plan. you should come run one of those.

[Justin86]

nice!!!

[sb_hbackDX]

I have been pondering with the idea of quad carbs for looooonng while and now that money is... somewhat abundant I think Im gonna go through with it. Since your one of the few guys on here with quad carbs I figured I'd ask a few questions...How is the car/carbs holding up since the conversion? Did you ever fab another intake mani? With four carbs...how is the gas mileage(important for poor college students!) Now I have access to a MIG welder for the aluminum and I also know how to use it so that shouldn't be a problem...But how long were your runners? I saw that they were pretty long for torque reasons due to your large cam...but I have a mild cam, Colt Triflo Stage 1. I have some measurements for the runners already but I would like to get your input. Now to the carbies
Did you create a fuel rail for them? What was your PSI in the line? I have been tuning and tinkering around with carbs for years and I'm sure you know how to tune also but how tough were those to tune? I have a Weber 32/36 and 38 also and those were not to bad to tune even thought I didn't have a Wideband O2 sensor...Growing up me and my dad worked on Holly's, Edelbrock's and SU's...Weber was a new one for me and I must admit there pretty badass but I want better throttle response too and I'm not really into the dual DOEC 40's...i hear there gas guzzlers and not half as cool as 4 mini carbies. Damn this message is long! Im sorry to make you read all this shit hahaha Well whenever ya free give me a write back. Adios man!

[lostforawhile]

I have been pondering with the idea of quad carbs for looooonng while and now that money is... somewhat abundant I think Im gonna go through with it. Since your one of the few guys on here with quad carbs I figured I'd ask a few questions...How is the car/carbs holding up since the conversion? Did you ever fab another intake mani? With four carbs...how is the gas mileage(important for poor college students!) Now I have access to a MIG welder for the aluminum and I also know how to use it so that shouldn't be a problem...But how long were your runners? I saw that they were pretty long for torque reasons due to your large cam...but I have a mild cam, Colt Triflo Stage 1. I have some measurements for the runners already but I would like to get your input. Now to the carbies
Did you create a fuel rail for them? What was your PSI in the line? I have been tuning and tinkering around with carbs for years and I'm sure you know how to tune also but how tough were those to tune? I have a Weber 32/36 and 38 also and those were not to bad to tune even thought I didn't have a Wideband O2 sensor...Growing up me and my dad worked on Holly's, Edelbrock's and SU's...Weber was a new one for me and I must admit there pretty badass but I want better throttle response too and I'm not really into the dual DOEC 40's...i hear there gas guzzlers and not half as cool as 4 mini carbies. Damn this message is long! Im sorry to make you read all this shit hahaha Well whenever ya free give me a write back. Adios man!i was going to ask him how they were running also. just to compare notes,i got some more done on mine recently and i've got some pics and a couple of videos up on the site. http://www.3geez.com/forum/showthread.php?t=61333 as far as pressure most of these side drafts run about 2-3 psi,it's fuel flow thats important on a carb not pressure. as long as the bowl can be kept full you're fine. on mine i'm running a holley low pressure regulator,i've got it set up on the factory carb right now,and i run about 3 psi. i built another pickup for the tank and i'm going to run a walbro pump under the body,that pumps fuel on demand. the stock fuel line is actually pretty decent,it's just the pump that sucks. we need to start a thread on here,just for those of us running multiple carbs,so we can all compare notes. :)

[cygnus x-1]

...Growing up me and my dad worked on Holly's, Edelbrock's and SU's...Weber was a new one for me and I must admit there pretty badass but I want better throttle response too and I'm not really into the dual DOEC 40's...i hear there gas guzzlers and not half as cool as 4 mini carbies.

Better throttle response than Webers? How do you mean? My 38/38 had awesome response; barely any throttle needed to cruise. If you want it to rev faster you need a lighter flywheel.

C|

[sb_hbackDX]

Yes I hear the 38/38 has damn good throttle response and in fact I have one but don't you think 4 39mm mini carbs would have slight better response that a large 2 barrel 38 carb? Thats a 39mm carby per cylinder :rockon: I don't want to junk my Weber's but its just a recent project i was working on...
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=330148074768&ssPageName=STRK:MEWA:IT&ih=014#ebayphotohosting
I already have cut the aluminum runners and an old EFI intake mani(using injector sites for vac log) I just have to make time to weld them together...What do ya'll think? This is also a cheap mod, well for me, the carbs were under $200 and apparently they were rebuilt and with low miles...I'm just concerned with the MPG with 4 39mm's:lol: Another issue is that the carbies are "electronically controlled"...:wtf: The on board CPU apparently controls the lift of the beveled slides of the carb by regulating the pressure above the diaphragms...could be a problem but hey a carb is a carb right :)

[cygnus x-1]

Not necessarily. In fact carbs that are too big can be worse than smaller carbs. They need to be matched to the engine so that it gets the right air/fuel mixture when the throttle is opened. A small engine may not draw enough air volume through a large carb to create the velocity needed for good fuel metering.

I'm not saying they won't have better response, but I think you'll be hard pressed to get better response than a properly tuned Weber.

C|


Yes I hear the 38/38 has damn good throttle response and in fact I have one but don't you think 4 39mm mini carbs would have slight better response that a large 2 barrel 38 carb? Thats a 39mm carby per cylinder :rockon: I don't want to junk my Weber's but its just a recent project i was working on...
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=330148074768&ssPageName=STRK:MEWA:IT&ih=014#ebayphotohosting
I already have cut the aluminum runners and an old EFI intake mani(using injector sites for vac log) I just have to make time to weld them together...What do ya'll think? This is also a cheap mod, well for me, the carbs were under $200 and apparently they were rebuilt and with low miles...I'm just concerned with the MPG with 4 39mm's:lol: Another issue is that the carbies are "electronically controlled"...:wtf: The on board CPU apparently controls the lift of the beveled slides of the carb by regulating the pressure above the diaphragms...could be a problem but hey a carb is a carb right :)

[Zufer]

sorry double post

[Zufer]

ok i know this is my thread and i haven't been posting in it.... but i will beg to differ with the hard to beat a weber comment. I had a very well tuned weber and when my carbs were properly tuned on the first try at my manifold it had way better response. however i also went with 34mm carbs because i felt from reading and calculations that it was all i would need to fuel properly up to 7k rpms. I have yet to get my newer shorter manifold tuned properly so i can't say how responsive it is... but hopefully in the next week or so.

Also for those thinking of trying this... all i can say is it is not for the feint of heart as my car has yet to idle properly for more than a few days because as the weather changes so frequently here in portland the mixture changes as well. This is also partly due to the large cam, but a lot of it is the carbs. that being said i am glad i have done this setup although i'm kinda frustrated with tuning right now

[lostforawhile]

Not necessarily. In fact carbs that are too big can be worse than smaller carbs. They need to be matched to the engine so that it gets the right air/fuel mixture when the throttle is opened. A small engine may not draw enough air volume through a large carb to create the velocity needed for good fuel metering.
I'm not saying they won't have better response, but I think you'll be hard pressed to get better response than a properly tuned Weber.
C|
this is one advantage over the webbers that the SUs have,they are a variable venturi carb, the piston controls the size of the venturi, by the amount of air flowing through it. less air needed,idle and cruise, the venturi gets smaller,open the throttle and the engine demands more air,the piston rises and the venturi gets bigger. this assures the mixture is always correct under all conditions. lets see a webber adjust itself like that. :) thats the inherent problem with all fixed venturi carbs, you can tune them at a comprimise at one point, but at the opposite ends of the operating range,they will always be out of tune. there are various fixes for this,such as power valves,accelerator pumps, booster venturis,etc. etc. etc. but it's still always a compromise. the SU is like having a carb that has almost infinite adjustment over the entire operating range. almost like a mechanical fuel injection system. this is also the reason that the same Su carb can be used on a number of different sized engines. the carb adjusts itself to the airflow of the engine.

[cygnus x-1]

Variable venturis are cool. :)

But my main point was that a larger carb does not necessarily equate to better throttle response. Manifold design and tuning has a lot to do with it as well.

C|

[lostforawhile]

right,but these carbs can act as both a larger carb and a smaller carb. smaller carb is better for cruise and low speed larger carb is better for wide open throttle. the venturi changes the size of the carb in essence

[A20A1]

Are your runners the same inner diameter all the way through or do they get wider as they get closer to the head or is that just the extra thickness of the stock manifold?

[hondaman1986]

any updates on how its running? what part of portland are you from i live in clackamas and would love to see this in person

[2oodoor]

He was on the other day, I would like to know how it runs as well, hearing it would be a bonus too :rockon:

[Ichiban]

Unfortunately, electonically controlled carbs are usually a disaster. Best of luck on that one.

Also, look at any (most) 2 or 4 barrel progressive carb. The primaries are way smaller to maintain high velocity required for good driveability and throttle response. The secondaries are huge, the assumption being that the engine is turning fast enough when they open that it's producing enough vacuum to support the added airflow, and thus meter the fuel properly.

[Zufer]

this is not an electronically controlled carb. And also it runs, hopefully in a couple weeks it'll have a better tune on it. and the it has a vacuum controlled slide to keep the velocity constant.

[Ichiban]

This is also a cheap mod, well for me, the carbs were under $200 and apparently they were rebuilt and with low miles...I'm just concerned with the MPG with 4 39mm's:lol: Another issue is that the carbies are "electronically controlled"...:wtf: The on board CPU apparently controls the lift of the beveled slides of the carb by regulating the pressure above the diaphragms...could be a problem but hey a carb is a carb right :)


This is what I was referring to.

[2oodoor]

^^^those were 1996 suzuki GSXR750 carbs^^^

[Zufer]

Here is a video of my quad motorcycle carb setup running on my car. It is running pretty well... but i still need to work on the tuning a bit. I installed a cold air intake setup this weekend so i figured i'd show you all how it was doing. All the fabrication was done by myself so i need to take some time to make it look pretty as i was more focused on making it work that the visual aspect.
http://youtube.com/watch?v=cUjgaccsM5M&feature=user

[86AccordLxi]

Man, that looks like ass :P :P :P :P

Nice zeph, sounds like it's running much better since the last time I saw it :D

Alex

[forrest89sei]

Yay!

[codyJDM]

That is so hot.

[2ndGenGuy]

Man that's rad. It's a legendary car from the 3geez rumors milling about the Pacific Northwest. Good to hear it in action. :D

[Civic Accord Honda]

damn dude thats sexy as hell! that poping sound when it revs down is sick too!
i love the color its the same color i have wanted to paint my car :)

[AccordB20A]

good job mate. sounds good.apart from the lack of backpressure causing the exhaust popping / its running rich. but id say that would be hard to tune???

[MessyHonda]

nice set up

[Hauntd ca3]

souds and looks cool dude
nothing wrong with the popping, i like it
betta to run a touch rich than lean eh
just need the big ass flames now eh dude

[2oodoor]

there is a 3 geezus, and he has spoken thru zufer

[GraniteLXI]

:cheers: Looks sweet, and sounds sweet besides the idle...thats what my 3gee sounded like when the ECU died on me but my car still wanted to run! (the idle, ran like a flat four except all the time lol)

[Zufer]

thanks for all the good comments. The tuning has been a pain but its getting close. I really need some sort of wideband to get it dialed in further. The off throttle pops i could care less... and if i just raise the idle a tiny bit it'll be fixed. Right now i need to wrok on getting the part throttle stuff dialed in a bit better. But over its doing very well.

[A18A]

thats cool!! :D

[bobafett]

idle is helped along by a 282 cam so its about as good as it gets. ;-)

[2oodoor]

it has a 282? I just got a better sounding listen at it.. I was going to say sounds like the cam timing was off before I read that. Zufer you really won't know where you are at until you get the wideband or at least AF meter of some sort, maybe a exhaust temp guage too.
I think you will have a little exhaust pulse sound back thru the intake side with these set ups at certain rpms regardless.
Awesome project

[Zufer]

ya i know i need to get a wideband on in. It took nearly a year to tune my weber without one and about 10 minutes to get it with one when i first put the cam in. But i lost the access to the one i've been using so i need to buy or find one i can use. The cam definitely makes the idle nearly impossible to get smooth. Hopefully in the next couple weeks i'll get it all tuned. But its definitely drivable now and its quite fun.

[MessyHonda]

yeah i know how you feel..it sucks trying to tune a cam...i have a stage 2 and it still will not idle right even tho mine has been tuned with a wideband and obd1 convertion...my lifters are making ticking noises

[mushroom_toy]

Very Sick man!

[knarg]

that's really cool, what type of suspension setup and wheel/tire combo do you have?

[AccordB20A]

didnt know it had a cam. must be a real grunter. spools up nice when you open it up :)

[lostforawhile]

carbs look great,i would go with a lower pitch muffler though. try a long glasspack. i think they all pop like that, it's just with the stock muffler it is so restrictive you can't hear it. mine does the same thing.

[EricW]

Nice work! Do you check the plugs to tune?

[headbanger]

very nice setup i think it sounds real good what bike is those carbs off of like a 750 or something.

[Zufer]

I have been using the plugs so far.

For suspension i have civic struts and sleeve coil overs. I also have strut bars and justins subframe braces front and rear. For wheels i have some sort of 17's for now but i'm cleaning up a set of volk 14's right now and i'll be running azenis on those.

Right now i'm saving to do a motor rebuild and then all i'll have left to finish is the brakes.

[A20A1]

Are the pics still working or is it just me?

[cygnus x-1]

Are the pics still working or is it just me?

I'm not seeing them either. :(

C|

[2oodoor]

:redx: