Carburetor Positioning?

Kefo

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#1
I have a 66ccSquareHead Grubee Skyhawk engine that I am currently installing on a bike, and have come across my first hiccup. The carburetor air intakes hits the seat post, however it could fit if I turned it an angle (about 15-20 degrees). Would the carburetor still function properly if I did so?
 


Timbone

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#2
Yes. You can even swing it all the way around the front and get some pressure assist - a kind of free turbo!
 


Steve Best

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#4
I have a 66ccSquareHead Grubee Skyhawk engine that I am currently installing on a bike, and have come across my first hiccup. The carburetor air intakes hits the seat post, however it could fit if I turned it an angle (about 15-20 degrees). Would the carburetor still function properly if I did so?
No you cannot angle the carb. The float bowl gasket surface has to be level in both planes.
Timbone was referring to the intake. You can build or bend the intake to face where ever you like (within some limitations).
The intake generally works best with a decline to cylinder. Its length affects power at rpm, be aware.
There is a "Z" intake that will solve your problem.


Steve
 

FurryOnTheInside

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#5
If it is just the plastic cover with the organ pipe looking bits, I have seen pics on here where someone drilled holes in the cover for more direct air flow.. I would think you can just cut out a section where it contacts the bike frame.
 

Frankfort MB's

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#6
If it is just the black air filter then you can take it off and put it on upside down

it acts as a forced induction since it should be above the engine and air flow will be better
 

FurryOnTheInside

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#7
If it is just the black air filter then you can take it off and put it on upside down

it acts as a forced induction since it should be above the engine and air flow will be better
That's interesting..
Is forced induction really good? Will it not affect the mix differently at different speeds?
 

Frankfort MB's

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#8
Lol it's just like a ram air intake on the old firebirds, just a straight flow of cold air to go into engine
I seriously doubt there is much of a increase in power when you do this
 

FurryOnTheInside

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#9
Lol it's just like a ram air intake on the old firebirds, just a straight flow of cold air to go into engine
I seriously doubt there is much of a increase in power when you do this
I just wondered if it goes lean when you go fast. I guess it depends on how much force is actually being created. Certainly it would be negligible in the example of an inverted stock filter cover but it made me wonder about it generally. Bit off topic though I guess.
 

Timbone

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#10
How can forced induction be a bad thing?

These motors depend upon air. Your topline RPM is basically the amount of air your engine can process. When you jump from say 5k to 8k RPM, that's a lot more air that must be delivered immediately into the system. Anything that helps that process has to be beneficial.
 

Frankfort MB's

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#11
How can forced induction be a bad thing?

These motors depend upon air. Your topline RPM is basically the amount of air your engine can process. When you jump from say 5k to 8k RPM, that's a lot more air that must be delivered immediately into the system. Anything that helps that process has to be beneficial.
Not just these motors but anymotor runs on air.
Have to test out one of those electric turbos hooked straight to the intake shoving air in through an ice box but that's another story ;)
 

FurryOnTheInside

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#12
How can forced induction be a bad thing?

These motors depend upon air. Your topline RPM is basically the amount of air your engine can process. When you jump from say 5k to 8k RPM, that's a lot more air that must be delivered immediately into the system. Anything that helps that process has to be beneficial.

I just wondered if it being speed dependent made the air:fuel mix inconsistent.
I read about how changing the stock air filter to a less restrictive one makes more power but necessitates a readjustment of the mix because it doesn't automatically mean more fuel drawn in too at the exact same ratio. That would be a consistent change so easy enough, you make a little adjustment and that's that.
Forced induction might be different.. I guess with a single speed bike maybeee that is okay.. In my mind it spells leaner and leaner the faster you go.
Why don't we see air scoops on the majority of the bikes?
Interested to hear about what people think.
 

Frankfort MB's

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#13
Because most people have noticed that one modification on a 2hp engine doesn't make much of a increase.... And actually the tuners that's on Fast and the Furious run better when they are extremely lean (also the reason why they blow flames) these bikes won't run right if they are a lean but if you think about it the very small air intake on the car prevents it from getting major air through the intake
 


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