CV carb vs everything else..

**gatch** · 24th February 2010, 21:27

I have been doing some light reading on the pros and cons of CV carbs. I have found that they are fantastic for smoothing out power delivery due to the equalizing of pressure etc yah de yah.

What I have noticed however is that nowhere does it mention they are good for much else..

If I was so crazy as to remove the cv part of the system and manually actuate the carb sliders would I expect a performance gain, mid to top end..

I'm only messing around with ideas here so go easy on me..

Good or bad idea ?

**Motu** · 24th February 2010, 21:33

They are good for a multi so you don't have to set the carbs every time you touch the throttle...for idle and cruise at least,WOT it doesn't really matter.It also makes a bike easier to ride at low speeds...a much smoother throttle response.If you don't care about idle and like to go WOT as soon as possible...do it.Slide carbs on more than 2 cyl is frustration.

**DangerousBastard** · 25th February 2010, 06:51

Originally Posted by gatch

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If I was so crazy as to remove the cv part of the system and manually actuate the carb sliders would I expect a performance gain, mid to top end..

Well you cant really. CV carbs have a downstream throttle butterfly, and the slide isn't designed to seal properly - rather just be a mechanism to actuate the needle.

My guess is, CV carbs are used in modern engines because they are economical to feed and easy to set up.

Steve

**onearmedbandit** · 25th February 2010, 08:19

And injection owns all. Easy to setup, easy to modify, response as good as any carb could ever hope for (at least with the latest generation), carbs are like, so 1980's.
(Although nothing beats a nice set of carbs in terms of looks on a lot of car engines, ie dellortos etc.

**hmmmnz** · 25th February 2010, 09:10

plenty of older bikes used round slide carbs, which is essentially what you are wanting to do with your cv's
i would suggest buying a set of them rather than trying to come up with a method of lifting the slides on your cv's
and no you wouldn't get any gains mid to top end as the only limiting factor bore size, you are not changing that, and at wot the slide moves out of the way so isnt limiting the flow, the only bonus to flat or round slide carbs is the response,
with in a 1/4 of a second there is no advantage of slide carbs, plus quite often with slide carbs you have to control your slides like what would happen automatically with cv carbs

**jonbuoy** · 25th February 2010, 09:55

Round slides give a pretty heavy throttle too when you got four of them tied together. Personally I've found carbs smoother than EFI at small throttle changes.

**motorbyclist** · 25th February 2010, 11:55

Originally Posted by hmmmnz

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plus quite often with slide carbs you have to control your slides like what would happen automatically with cv carbs

+1

slide carbs are a great way to stall/bog an engine

**FilthyLuka** · 25th February 2010, 16:05

Originally Posted by Motu

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Slide carbs on more than 2 cyl is frustration.

Aint that the truth.

Slide carbs can usually offer you a bit more oomph, but at a certain cost. They really dont respond well to kack-handed foolery

**AllanB** · 25th February 2010, 16:08

Injection is the bizzzzz. Well until it goes wrong on the side of the road!

**gatch** · 25th February 2010, 17:24

Originally Posted by Motu

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They are good for a multi so you don't have to set the carbs every time you touch the throttle...for idle and cruise at least,WOT it doesn't really matter.It also makes a bike easier to ride at low speeds...a much smoother throttle response.If you don't care about idle and like to go WOT as soon as possible...do it.Slide carbs on more than 2 cyl is frustration.

I had thought as much..

Originally Posted by DangerousBastard

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Well you cant really. CV carbs have a downstream throttle butterfly, and the slide isn't designed to seal properly - rather just be a mechanism to actuate the needle.

My guess is, CV carbs are used in modern engines because they are economical to feed and easy to set up.

Steve

Yes you could, removal of butterfly and the diaphragm mechanism, machining of top of car and slider to accept a cable.

Originally Posted by onearmedbandit

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And injection owns all. Easy to setup, easy to modify, response as good as any carb could ever hope for (at least with the latest generation), carbs are like, so 1980's.
(Although nothing beats a nice set of carbs in terms of looks on a lot of car engines, ie dellortos etc.

I'm not that keen.. Or cashed up..

Originally Posted by hmmmnz

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plenty of older bikes used round slide carbs, which is essentially what you are wanting to do with your cv's
i would suggest buying a set of them rather than trying to come up with a method of lifting the slides on your cv's
and no you wouldn't get any gains mid to top end as the only limiting factor bore size, you are not changing that, and at wot the slide moves out of the way so isnt limiting the flow, the only bonus to flat or round slide carbs is the response,
with in a 1/4 of a second there is no advantage of slide carbs, plus quite often with slide carbs you have to control your slides like what would happen automatically with cv carbs

You would effectively increase the bore of the carb by removing the butterfly setup..

**roadracingoldfart** · 27th February 2010, 19:47

Originally Posted by gatch

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I have been doing some light reading on the pros and cons of CV carbs. I have found that they are fantastic for smoothing out power delivery due to the equalizing of pressure etc yah de yah.

What I have noticed however is that nowhere does it mention they are good for much else..

If I was so crazy as to remove the cv part of the system and manually actuate the carb sliders would I expect a performance gain, mid to top end..

I'm only messing around with ideas here so go easy on me..

Good or bad idea ?

I just wanna hear what Chris Starr says when you ask him !!!!...Hahahahahaha, he will slap you .