Carb question

It depends on many factors.
If you manage to put it on a stock Briggs 206 it will actually be a disadvantage.
If you put it on and engine that has the displacement, valve size, port size etc to accept it then it then it will improve things.
Will a Holly 4 barrel carb work on a Briggs 206?
I recently took a 32 mm Mikuni off a 14.5 Cid engine and put a 28 mm Mikuni on and it improved the HP throughout the entire rpm range.
It made more HP on the bottom end and the top end.
 
br2715 said:
Is the 32mm mikuni that much more Of an advantage over the 28mm? Advantages or disadvantages?
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As jimbo said, too much carb isn't necessarily a good thing, best thing to do is to visit with ec or competition carbs, let them know your motor combo and they will recommend the size of carb they feel will be most efficient for your motor....I run an open stroker animal and with my combo of internals, a 28mm alky was their recommendation, won a feature race first time out with it....so again, bigger isn't always better....😉
 
well you prob. heard of block buster carbs, we ran a 28mm on and open animal for a long time, I went to a 34mm clements and broke two blocks, I haven't built it back yet and put the 28mm back on to see what happens, so just saying its like putting a turbo on a bottom end in a car not made for it and forcing that much air in, it most time don't work.
 
"Force more air in"? Maybe it was the things you did because of the bigger carb? More clutch slip, more RPM? And You increase the venture area by about 72%, that's a bunch.
 
Warning: this post is boring.

The atmospheric pressure is apox. 14.696 PSI. That is at sea level.

The expanding volume created by the piston moving downwards in the cylinder bore creates a vacuum in the cylinder - an area where pressure is lower than the outside atmospheric pressure. To be “physics accurate” about it, what happens is the higher outside atmospheric pressure “pushes” air into the lower pressure area that has been created inside the cylinder, but it’s also accurate to think of it as the air being ‘sucked’ in.
So it really does not matter which analogy you use, the rules are still the same. Can't change physics, period. we can only argue about the terms.
If you take a tire and put 15 psi of air in it and took it to outer space, then took the same air pressure gauge, what would the pressure read then Or if you took it down in the ocean to a depth of approx 33 1/3 ft. down, What would it read then.
 
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Well written, but I'm afraid your conclusions and analogies are totally flawed.
Air flows because it's push. It's push from a high-pressure area to a low-pressure area. There is no such thing as "suck". I stress this point because I believe it makes a difference when studying carburetor airflow and fuel flow.
 
I did not write that Al.
I simply copied a page out of technical manual written by a chief engineer for Holman Moody Racing. An Arm of Ford racing
I just wanted to see if you would argue with it.
 
Al, you mention that it's important to understand there is no such thing as "suck" to better understand carb airflow and fuel flow, correct?
Could you explain for us how the fuel is delivered from the main nozzle to the venturi?

Not trying to start an argument, mind you, I think I understand your point; just wondering how you able to explain the fuel in relation to it being pushed rather than sucked, (going from higher pressure to lower pressure,) for us since you brought it up.

Remember, the fuel bowl is not pressurized - it is vented to atmospheric pressure.


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🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
32 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
Where does the low pressure come from?
alvin l nunley said:
Well written, but I'm afraid your conclusions and analogies are totally flawed.
Air flows because it's push. It's push from a high-pressure area to a low-pressure area. There is no such thing as "suck". I stress this point because I believe it makes a difference when studying carburetor airflow and fuel flow.
Click to expand...
 
One Fast Kat said:
I did not write that Al.
I simply copied a page out of technical manual written by a chief engineer for Holman Moody Racing. An Arm of Ford racing
I just wanted to see if you would argue with it.
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Yeah, but really Kat, do you think that guy knows anything about pressure differentials or air movement. Hmmmm............
 
95 shaw said:
Where does the low pressure come from?
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Atmospheric pressure is approximately 15 psi at sea level. Any pressure lower than that is considered a vacuum and is measured in powers of 10. 10 to the 8th, for all practical purposes, is considered a perfect vacuum. Not quite, but close enough for all practical uses.

As the piston goes up and down, it alternately creates a pressure and a vacuum.

Only in outer space can you find a perfect vacuum. Even at that, there are some qualifications.
 
CarlsonMotorsports said:
Al, you mention that it's important to understand there is no such thing as "suck" to better understand carb airflow and fuel flow, correct?
Could you explain for us how the fuel is delivered from the main nozzle to the venturi?

Not trying to start an argument, mind you, I think I understand your point; just wondering how you able to explain the fuel in relation to it being pushed rather than sucked, (going from higher pressure to lower pressure,) for us since you brought it up.

Remember, the fuel bowl is not pressurized - it is vented to atmospheric pressure.


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
32 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
Click to expand...
The suck vs push debate has been going on forever. From a practical standpoint, does it really matter? A carb works by manipulation of air velocity and therefore pressure. One way or another, flow is created due to pressure differential, just like the way wind is created through pressure differentials in the atmosphere.
 
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