will a S&S Carb or c/v add power?
Thread Starter
|
Outstanding HDF Member
Joined: Jun 2008
Posts: 2,374
Likes: 5
From: redbank new Jersey
will a S&S Carb or c/v add power?
I have a stock 1989 1200 with a c/v carb, drag pipes and ss air cleaner. I have a few bucks to spend and would love to change over to a new s&s carb and trash my c/v. I do not want to change my pipes or anything else I like the bike the way it is but would like to upgrade the carb. Would the s&s carb alone add any power? I dont care about the money and I know the c/v carbs are very good but would love to try one. So is a carb a carb? I did hear from one guy years ago that there the best thing ever and add 4HP but not sure if the guy was right. Thanks
Outstanding HDF Member
Joined: Aug 2007
Posts: 2,225
Likes: 4
From: fegfsg
get one that is the right size bore for your engine.
think about it like this, the size of your carb is the real MAIN jet for your engine. the maximum amount of air that the engine can inhale at any given moment will pass entirely through your carbs throat. we know that smaller holes make a given amount of air travel faster, and a larger hole passes more air at any given moment, but the air travels slower.
in an engine, you want to be able to get as much air in as the valves open, there is lots of ways to do this, but a properly tuned street engine will have a somewhat smaller diameter carb bore so that the air flows faster into the combustion chamber, this increases peak torque and real world power at the cost of peak horsepower at your rev limit, but no one on the street uses that power.
i know it seems long, but if you are serious about adding noticable power than by all means get a carb with a diameter equal to your stock carb unless you have lots of headwork and cam work done, in which case it is better to have a slightly bigger carb to take advantage of that flow.
the biggest advantage to the aftermarket carbs is how they mix the fuel and air and deliver it to the engine. which is to say that most of the good ones will make more power than a stock carb.
either way, send me your old stocker carb when your done, i can put it to use!
(im serious, ill even pay for shipping)
think about it like this, the size of your carb is the real MAIN jet for your engine. the maximum amount of air that the engine can inhale at any given moment will pass entirely through your carbs throat. we know that smaller holes make a given amount of air travel faster, and a larger hole passes more air at any given moment, but the air travels slower.
in an engine, you want to be able to get as much air in as the valves open, there is lots of ways to do this, but a properly tuned street engine will have a somewhat smaller diameter carb bore so that the air flows faster into the combustion chamber, this increases peak torque and real world power at the cost of peak horsepower at your rev limit, but no one on the street uses that power.
i know it seems long, but if you are serious about adding noticable power than by all means get a carb with a diameter equal to your stock carb unless you have lots of headwork and cam work done, in which case it is better to have a slightly bigger carb to take advantage of that flow.
the biggest advantage to the aftermarket carbs is how they mix the fuel and air and deliver it to the engine. which is to say that most of the good ones will make more power than a stock carb.
either way, send me your old stocker carb when your done, i can put it to use!
(im serious, ill even pay for shipping)
Grand HDF Member
Joined: May 2007
Posts: 3,870
Likes: 499
From: Alberta
If it was me; I'd get a pair of pipes (Khrome Werkes are my favorite; sleek one-piece stock look, deep sound and well made) and a dyno tune.....no aftermarket carb parts; just HD jets as required.
That's what I did when I had my Sporty. A good solid "baseline" for future mods and a bike that's making the HP built into it. My '01 ended up at 100hp/88tq with the help of HeadQuarters; was a real blast to ride.....
That's what I did when I had my Sporty. A good solid "baseline" for future mods and a bike that's making the HP built into it. My '01 ended up at 100hp/88tq with the help of HeadQuarters; was a real blast to ride.....
Club Member
Joined: Feb 2007
Posts: 16,320
Likes: 306
From: Boynton Beach, FloriDuh
+1 If you are looking for better street performance, get rid of the drag pipes.
Road Captain
Joined: Jun 2007
Posts: 531
Likes: 1
From: S.C.
I doubt that you will see any improvement that will justify the expense of the new carb with a stock engine - if you do see a big improvement it will be because your current carb is not jetted properly. The CV carb will flow enough air to satisfy the engine and when jetted properly will give you a great bang for the buck. If it was me I'd spend the money for the new carb on a dyno tune to maximize what you currently have. BTW, I am a big fan of S&S carbs but I think on a stock engine the CV carb is fine properly set up.
And I agree with the others comments on the drag pipes. At a minimum I'd add a washer lollipop to assist with the low back pressure. This is a cheap solution to improving the dip in low/mid range performance casused by the drag pipes.
And I agree with the others comments on the drag pipes. At a minimum I'd add a washer lollipop to assist with the low back pressure. This is a cheap solution to improving the dip in low/mid range performance casused by the drag pipes.
Last edited by EVO80; Jan 16, 2009 at 08:53 AM.
Trending Topics
Road Warrior
Joined: Jan 2008
Posts: 1,387
Likes: 1
From: Saint George, Utah
I have an S&S on my 1200 and dislike it very much. No matter what, when you gas it from the line there is a slight hesitation and then it goes. Mikuni is the way to go, and if you ever take your bike to higher altitudes the S&S doesn't compensate and your bike will run richer due to the altitude change. Get rid of them drags, or put some baffles in to increase some hp, but don't waste your money on an S&S. I like that S&S is made in America, and they do put out quality products but their carbs just don't perform like a CV.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider
Verdad Gallardo
Road Master
Joined: Nov 2007
Posts: 1,223
Likes: 3
From: Peoria, AZ
Buy a cam and heads! A properly tuned CV carb will work fine until you start adding other mods: I have an '01 XL1200c with stock CV and Drag Specialty drag pipes (that's it so far) and pulled 75 HP/68 torque when I dyno'd it at school and re-jetted (which is not too shabby with the drags although hindsight I'd have bought a "better" set of pipes). Drags pipes do have their limitations but can be "tuned out" (I actually lose more high end now) for better cruising.
Thread Starter
|
Outstanding HDF Member
Joined: Jun 2008
Posts: 2,374
Likes: 5
From: redbank new Jersey
I like my bike loud and love the sound drag pipes make so ill never change pipes. I live near a biker gang and a freeway and thats all I hear is bikes run wide open all day long past my house. I ride with about 10 harleys all running wide open pipes even the bikes I see all over my area run st8 drags. Its funny to hear how much people hate drag pipes on here before this forum I never new there was other pipes on the market. I really dont care about the power loss from the pipes I just wanted to no when I change over to a s/s carb if i would pick up a few HP. The bike has great power getting a few more HP would allways be nice lol