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Author Topic: Riddle me this, riddle me that, a four into one carb could it do that!!  (Read 1837 times)

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Offline Jt550

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Riddle me this, riddle me that, a four into one carb could it do that!!
« on: March 24, 2011, 07:50:27 PM »
I've been BACK & FORTH with this.... 

I got this bright idea to do 1 34mm Mikuni on a 71 CB500

My guru of a friend an bike tech & racer of almost 35 years swears up & down it will work......

Yet everyone I told doubts this.... Some say it won't start, some say it won't rev over 4K....

But FTW Who's right???

Im dying to know if it will work & have the "I TOLD YOU SO" moment when it does......  Or just punch & scream and cut the plenum in half & add a second carb..... But its 1 for now.....

What say you??? There's gotta be more then one of you out there has a background in this.........   
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Offline Gordon

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Re: Riddle me this, riddle me that, a four into one carb could it do that!!
« Reply #1 on: March 24, 2011, 07:58:42 PM »
Two carbs work because it's relatively easy to keep the intake runners at the same length and shape.  Try doing that with one carb and you end up with extremely long, convoluted intakes. 

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Offline Retro Rocket

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Re: Riddle me this, riddle me that, a four into one carb could it do that!!
« Reply #2 on: March 24, 2011, 08:08:53 PM »
I would say that looking at the diagram you have there that the outside cylinders will run lean....
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Offline hesselfuzz

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Re: Riddle me this, riddle me that, a four into one carb could it do that!!
« Reply #3 on: March 24, 2011, 08:18:35 PM »
Of course it will "work". They used to run all kinds of straight sixes on little bitty single barrel carbs. Now will it perform? Probably like those old sixes did. Not hot rods to be sure.
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Offline Jt550

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Re: Riddle me this, riddle me that, a four into one carb could it do that!!
« Reply #4 on: March 24, 2011, 08:22:00 PM »
Quote from: Retro Rocket on March 24, 2011, 08:08:53 PM
I would say that looking at the diagram you have there that the outside cylinders will run lean....

Ive heard that one too...

Yet I keep getting referred back to a carborated inline four 70/80's Honda Civic or or Toyota Tercel... One carb, one manifold, 4 cylinders....    ::)  
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Offline Jt550

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Re: Riddle me this, riddle me that, a four into one carb could it do that!!
« Reply #5 on: March 24, 2011, 08:26:29 PM »
Quote from: hesselfuzz on March 24, 2011, 08:18:35 PM
Of course it will "work". They used to run all kinds of straight sixes on little bitty single barrel carbs. Now will it perform? Probably like those old sixes did. Not hot rods to be sure.

Its a 500,,, How HOT ROD can you get..? if it gets to 65 in 10sec's & can hold 85 I be a happy camper....

But your in the ball park with the same thing by buddy said, an he also spoke of his 64 Mustang inline 4... It was no dragster but a good runner...

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Tyler Durden: You're not your job. You're not how much money you have in the bank. You're not the car you drive. You're not the contents of your wallet. You're not your f*<king khakis. You're the all-singing, all-dancing crap of the world.

-78 CB550k with a BIG #$%* Eating Grin-

Offline Jt550

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Re: Riddle me this, riddle me that, a four into one carb could it do that!!
« Reply #6 on: March 24, 2011, 08:36:40 PM »
I've seen vintage pics of dudes with 750 chops running DB Hollies off one side..... Any one ever dealt with one of those one on one... That seems like a hand full all to it self...

But thats were this idea stemmed from...... But I figure the side draft would cause a lean condition on the last two cylinders, so that was the reasoning for sticking it in the middle..... ;)
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Tyler Durden: You're not your job. You're not how much money you have in the bank. You're not the car you drive. You're not the contents of your wallet. You're not your f*<king khakis. You're the all-singing, all-dancing crap of the world.

-78 CB550k with a BIG #$%* Eating Grin-

Offline excellrec

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Re: Riddle me this, riddle me that, a four into one carb could it do that!!
« Reply #7 on: March 25, 2011, 12:33:20 AM »
You could make all the runners equidistant in length by lengthening the inner two by maybe having them curve around or something like that.
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Offline Gordon

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Re: Riddle me this, riddle me that, a four into one carb could it do that!!
« Reply #8 on: March 25, 2011, 01:46:10 AM »
Quote from: Jt500 on March 24, 2011, 08:22:00 PM
Quote from: Retro Rocket on March 24, 2011, 08:08:53 PM
I would say that looking at the diagram you have there that the outside cylinders will run lean....

Ive heard that one too...

Yet I keep getting referred back to a carborated inline four 70/80's Honda Civic or or Toyota Tercel... One carb, one manifold, 4 cylinders....    ::)  

A sohc4 makes about twice the hp/cc as the carbureted 4-cyl Honda car engines. 
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Offline dave500

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Re: Riddle me this, riddle me that, a four into one carb could it do that!!
« Reply #9 on: March 25, 2011, 01:53:01 AM »
Quote from: hesselfuzz on March 24, 2011, 08:18:35 PM
Of course it will "work". They used to run all kinds of straight sixes on little bitty single barrel carbs. Now will it perform? Probably like those old sixes did. Not hot rods to be sure.
those old sixes revved to about 5 grand,the long branch chrysler sixes had lean end cylinders.
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Offline Jt550

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Re: Riddle me this, riddle me that, a four into one carb could it do that!!
« Reply #10 on: March 25, 2011, 02:45:45 AM »
Man I was lit last night,,,, Some how... Cant even remember how I posted this in 2 different places....

But it seems cool to have the both to compare too. It is interesting to see how we all think......

http://forums.sohc4.net/index.php?topic=86181.new#new

Check the "HIGH TECH SIDE" of this......
« Last Edit: March 25, 2011, 02:47:48 AM by Jt500 »
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-78 CB550k with a BIG #$%* Eating Grin-

Offline SohRon

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Re: Riddle me this, riddle me that, a four into one carb could it do that!!
« Reply #11 on: March 25, 2011, 05:43:01 AM »
Quote
he also spoke of his 64 Mustang inline 4... It was no dragster but a good runner...

No such thing. Original Mustangs had straight sixes or V8s, never a four cylinder; I'm not even sure Ford was manufacturing a 4-cylinder engine at that time for any of their products. Also, the intake manifolds on these cars are designed so that each cylinder has a similar intake length to even out the lean condition described above. You need to redesign your intakes or be subjected to constant fouling.
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Offline Jt550

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Re: Riddle me this, riddle me that, a four into one carb could it do that!!
« Reply #12 on: March 25, 2011, 08:35:23 AM »
Quote from: SohRon on March 25, 2011, 05:43:01 AM
Quote
he also spoke of his 64 Mustang inline 4... It was no dragster but a good runner...

No such thing. Original Mustangs had straight sixes or V8s, never a four cylinder; I'm not even sure Ford was manufacturing a 4-cylinder engine at that time for any of their products. Also, the intake manifolds on these cars are designed so that each cylinder has a similar intake length to even out the lean condition described above. You need to redesign your intakes or be subjected to constant fouling.

Thanks SohRon, for the Ford history lesson, it's been attest 10yrs an 3 jars to the frontal lobe... BUT I do remember looking under the hood an laughing my ass off to see this little thing stuck in that cavern of an engine bay.. You could put a family of for under that hood!

Anyway.......
How would you redign the intake? Angle the outer inlets tords the middle?

An this might be a maut point to some... But what IF the carb size were bigger?? 38mm 44mm  VM Mikuni's "yes I love Mikuni's"

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Tyler Durden: You're not your job. You're not how much money you have in the bank. You're not the car you drive. You're not the contents of your wallet. You're not your f*<king khakis. You're the all-singing, all-dancing crap of the world.

-78 CB550k with a BIG #$%* Eating Grin-

Offline mlinder

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Re: Riddle me this, riddle me that, a four into one carb could it do that!!
« Reply #13 on: March 25, 2011, 08:58:26 AM »
Something like this would work. You'd have to do math for size of obstruction in plenum, but whatevs.
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