40 replies to this topic

[EA HOMIE]

im new at this carbs and im just trying to see whats the best thing to do. its a civic 1.5L im currently rebuilding the motor (shaving the head, valves, piston, piston rings, gaskets, ect.) do to ticking and knocking. but as far for carbs i dont know what to do. ive found a Weber carb but i was reading the forms and if i can make just as much power but stock might as well not change it. Any tips?

[3gencivic]

seeing as your in the states. you have the basterd carb with amilion vac lines.
you can soruce out a cdn intake and carb we have only 3 vac lines an can devac an get more horse power easly.

other then that you are lookng at getting webber carbs.

[EA HOMIE]

i dont mind getting the webber. but i was reading and there saying its harder too tune and get it running right. what u think?

seeing as your in the states. you have the basterd carb with amilion vac lines.
you can soruce out a cdn intake and carb we have only 3 vac lines an can devac an get more horse power easly.

other then that you are lookng at getting webber carbs.

[EuphoricBlue]

i dont mind getting the webber. but i was reading and there saying its harder too tune and get it running right. what u think?

It's true, but only because a Webber is generic carb, you have to jet it to match the engine. A CDM carb is designed to run with our cars so you only need to worry if it works or not; only after some real engine mods do you need to worry about jetting.

Personally, I think a Webber would be WAY easier to tune for performance than a USDM carb. I dislike USDM carbs for our cars, and I've never even owned one.

[Captain Regular]

It's true, but only because a Webber is generic carb, you have to jet it to match the engine. A CDM carb is designed to run with our cars so you only need to worry if it works or not; only after some real engine mods do you need to worry about jetting.

Personally, I think a Webber would be WAY easier to tune for performance than a USDM carb. I dislike USDM carbs for our cars, and I've never even owned one.

You probably have more experience with carbs in general than I do, but from what I've gathered about the CDM carbs (and done with my USDM one), it's not that difficult to devac a USDM to the point where it's as simple and trouble-free as a CDM. I have mine thorougly devacced and slimmed down (mostly per DarkHands carb research thread) and put a manual choke on. I've been driving it like that for nearly a year, daily, and haven't had one bit of trouble out of the carb, and I've been getting about 36-38 MPG and decent power out of it. I can't say I've TUNED it for performance or extra HP or anything like that, I would lean it more towards making it burn leaner and more efficient, but after a good devac, I've got no complaints about my USDM carb. AFTER a devac, before it was a friggin' nightmare.

[EuphoricBlue]

Oh, one thing worth mentioning... if you do decide to get a weber or a CDM carb, consider that to get the most out of them you'll need to swap to the SI(or CDM DX) head because of the CVCC in USDM DXs.

Ultimately it's about how much air you can flow and where you want the power. There isn't really any power to be made at the carb unless it's restricting flow. In stock configuration they do, which is why you get a noticeable difference when you disable the fuel economy and "automated" devices. After that is done your gains from tweaking the carb become minimal, it's time to open up the head. After the head is opened up then you go back to the carb (Enlarge ports/replace with bigger carb) This is mostly why there isn't a huge difference to be seen between a Webber and a stock carb, on a stock head.

CVCC vs Regular heads the main difference is:
CVCC - more suited to tuning for economy.
Regular - better choice for tuning for power.

[EA HOMIE]

How do I know witch head I have? The motor is a d15a3. But watever head I have I was planing on sheaving it redoing the valves cause its ticking.

Oh, one thing worth mentioning... if you do decide to get a weber or a CDM carb, consider that to get the most out of them you'll need to swap to the SI(or CDM DX) head because of the CVCC in USDM DXs.

Ultimately it's about how much air you can flow and where you want the power. There isn't really any power to be made at the carb unless it's restricting flow. In stock configuration they do, which is why you get a noticeable difference when you disable the fuel economy and "automated" devices. After that is done your gains from tweaking the carb become minimal, it's time to open up the head. After the head is opened up then you go back to the carb (Enlarge ports/replace with bigger carb) This is mostly why there isn't a huge difference to be seen between a Webber and a stock carb, on a stock head.

CVCC vs Regular heads the main difference is:
CVCC - more suited to tuning for economy.
Regular - better choice for tuning for power.

[EuphoricBlue]

It's most likely the 16 valve CVCC. Considering the mess of vacuum lines you removed. If it was any other head you shouldn't have that carb on it.

If you want to be 100% sure, pop the valve cover and count the valves. 16 valves = CVCC, 12 valves = Other.

[zakats]

one of the greatest follies of the USDM cars was the application of cvcc heads :-/ the CDM DX head is the one to have... one of these durn canooks chiming in here ought to know of a CDM dx head that is available!

[EA HOMIE]

mine is 12 valves. i should be good then?

It's most likely the 16 valve CVCC. Considering the mess of vacuum lines you removed. If it was any other head you shouldn't have that carb on it.

If you want to be 100% sure, pop the valve cover and count the valves. 16 valves = CVCC, 12 valves = Other.

[EuphoricBlue]

That's odd, I wasn't aware the states had 12 valve DXs. Do you know the history on the car? Was an engine transplant done?

But if it is in fact 12 valve then you should be set for the head... and carb I could guess... I can't really say much about what you have, it's a bit of a curve ball for me to hear you have a 12 valve head.

[EA HOMIE]

wen i got the pappers if im not mistaken it was from AZ. would that make a difference?

That's odd, I wasn't aware the states had 12 valve DXs. Do you know the history on the car? Was an engine transplant done?

But if it is in fact 12 valve then you should be set for the head... and carb I could guess... I can't really say much about what you have, it's a bit of a curve ball for me to hear you have a 12 valve head.

[othrpinkthng]

That's odd, I wasn't aware the states had 12 valve DXs.

My 86 CRX Dx has 12 valves as well.

That is what they came with (I bought mine new)

Maybe the HF is different, ...not sure.

[EuphoricBlue]

Weird, I thought all USDM non SIs had CVCC... If you have 12 valves you can't have CVCC...

Could someone far more knowledgeable in the USDM engines than me (not tough to do ), chime in and list everything that was sold, in what models, and what years?

[EuphoricBlue]

Wait, something was just came to my attention...

well my car has 12 valves plus 4 aux valves so its a 16 but is says it's a 12 will it still fit

Did you guys here read that it has 12 valves or did you actually count?