Topic: Single Carb cb550 Video

[Lostboy Steve]

Has anyone seen this on youtube? lol pretty neat idea if you were sold a bike with destroyed carbs. The manifold may even prove useful in a turbo setup if altered a bit. Leaded copper pipes if polished up might look pretty nice too.

[Scott S]

 Anytime I see an SOHC4 with less than 4 carbs, I feel like someone just didn't have the cajones to get 4 carbs running right. Unless there's a turbo or F.I. involved.

[Lostboy Steve]

...and i tend to agree, especially because I did two racks of carbs on my 77 after finding a gross vacuum leak in my first set, but nontheless pretty cool.

[seanbarney41]

It sounds like #$%*.

[goldarrow]

The other 3 carbs were sold off to fund the project???

[Dimitri13]

Someone saw a Harley chopper side-draft carb and said "I want that!"

Neat idea, and I'm jealous of the accelerator pump.

[dusterdude]

See what?

[cb650]

650 frame

[carnivorous chicken]

That poor #1 cylinder, I'm guessing it doesn't get much fuel.

[flybox1]

That poor #1 cylinder, I'm guessing it doesn't get much fuel.

+1

[riverfever]

I've had farts that sounded better.

[jaguar]

I see ZERO point in set ups like this.

[RevDoc]

That poor #1 cylinder, I'm guessing it doesn't get much fuel.

That was my immediate thought as well. #1 & 2 would be lean as hell and you would have to get into all sorts of B/S jetting to get it running anywhere near decent! If that would even be possible.

[Deltarider]

That poor #1 cylinder, I'm guessing it doesn't get much fuel.

A lot of "+1" comments, so I take it someone can explain to us dumbheads why this would be the case.
Apart from the exhaust the engine seems to run quite silky.
BTW, that ram-air setup is an ideal flycatcher.

[carnivorous chicken]

That poor #1 cylinder, I'm guessing it doesn't get much fuel.

A lot of "+1" comments, so I take it someone can explain to us dumbheads why this would be the case.
Apart from the exhaust the engine seems to run quite silky.
BTW, that ram-air setup is an ideal flycatcher.

A set up like that, with a single carb on one side of the manifold, means that the gas/air for the #1 carb has to rush by three cylinders prior to arrival, and all three are competing to suck it in too. Most manifolds that connect to four cylinders (think V-8s, or even other single carb attempts on SOHC fours) put the carb in the middle of the cylinders.

[RevDoc]

That poor #1 cylinder, I'm guessing it doesn't get much fuel.

A lot of "+1" comments, so I take it someone can explain to us dumbheads why this would be the case.
Apart from the exhaust the engine seems to run quite silky.
BTW, that ram-air setup is an ideal flycatcher.

A set up like that, with a single carb on one side of the manifold, means that the gas/air for the #1 carb has to rush by three cylinders prior to arrival, and all three are competing to suck it in too. Most manifolds that connect to four cylinders (think V-8s, or even other single carb attempts on SOHC fours) put the carb in the middle of the cylinders.

You got to it before I did, CC. I've seen other attempts like this in industrial & marine applications and they all work poorly.

Yes, the engine may sound like it idles smoothly but try putting it under load and see what happens. Honda engineers knew what they were doing when they designed our engines with individual carbs for direct feed rather than one of these contraptions!

[buffalogt750]

If you go on youtube and find this video the builder says it made 92 horsepower on a dyno. He probably meant 9.2 horsepower.

[strynboen]

the optimal vas 1 floate champer vho vas lined up to the 4 kaburators.. one flote/ gas valve is easyer then 4..
is it possibel to remove the 3 floats gas/ valve..and make one as a marster..and puts lines to the other bovls..to fill them..but only have one to kontrol and delevre to the rest.

.but  i like the stock ..it vorks for me..after i kleaned the rust aut of my tank

[curemode2002]

That and the carb he is using is going to be sucked dry at higher RPMs. I could see going with one or two webber carbs like the drag guys used to back in the day.

[jaguar]

Maybe at the crank....and he used a 75% loss formula

[jonda500]

That poor #1 cylinder, I'm guessing it doesn't get much fuel.

A lot of "+1" comments, so I take it someone can explain to us dumbheads why this would be the case.
Apart from the exhaust the engine seems to run quite silky.
BTW, that ram-air setup is an ideal flycatcher.

My personal opinion (initial startup and throttle pump aside), is that #1 would get the same air/fuel ratio as the other three cylinders.
My vacuum guages have two much longer tubes that screw into the two inner cylinder manifolds  but this doesn't mean they get a lower vacuum reading than the short ones - I have checked this!

I agree that single carb looks too small for that purpose (unless it came off a 1000cc twin or something!)

John

[carnivorous chicken]

My vacuum guages have two much longer tubes that screw into the two inner cylinder manifolds  but this doesn't mean they get a lower vacuum reading than the short ones - I have checked this!

John

Completely different concept. Your vacuum gauges are measuring pull (vacuum) of the carbs, run through the same tube. Distance doesn't matter. Vacuum for #1 carb on this could be the same as #4, but that doesn't mean that it's getting the same amount of fuel. It's being siphoned off by 4, then 3, then 2, and 1 is getting what makes it that far. There's a reason you don't see SOHC fours with single carbs very often. It may sound easy (if you're lazy and can't figure out four carbs) but it's not very effective.

[Deltarider]

It's being siphoned off by 4, then 3, then 2, and 1 is getting what makes it that far.

I'm lost here. Don't they siphon by turn, alternatively? Doesn't the vacuum of 1 siphon as hard as the others? And isn't there a constant feed? What fysics is this? The way you guys put it, I can't understand how it could run at all. But it does and quite silky I must say.

[seanbarney41]

It's being siphoned off by 4, then 3, then 2, and 1 is getting what makes it that far.

I'm lost here. Don't they siphon by turn, alternatively? Doesn't the vacuum of 1 siphon as hard as the others? And isn't there a constant feed? What fysics is this? The way you guys put it, I can't understand how it could run at all. But it does and quite silky I must say.

hey,if you think it sounds great, go ahead and run that #$%* on your own bike then

[buffalogt750]

It's being siphoned off by 4, then 3, then 2, and 1 is getting what makes it that far.

By that theory any intake manifold with unequal length runners can't work? So the one I have pictured here, or any 6 cylinder or V8 manifold for that matter, is total crap and will starve the cylinders farthest from the carb? The carb he uses is from a Harley Softtail so I'm sure it is big enough. I would never attempt this but the bike sounds alright to me. However the 92 horsepower he claims is certainly total BS.