Why do larger roots blowers use 2 carbs?
#1
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Joined: Nov 2005
Posts: 387
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From: Wayland, MI
Curious why the bigger roots stuff use 2 carbs. Is one large carb possible? Such as a 1050 dominator in a 6-71 style blower. I have a 525sc with a weiand 177 and am trying to figure out if a blower upgrade is worth the effort.
#3
Fuel distribution is part of it. The main thing is when you start pushing through more air, you need more fuel and this can only be accomplished with 2 carbs.
I don't even think they make a single carb plate for anything larger than a 250/256 blower.
I don't even think they make a single carb plate for anything larger than a 250/256 blower.
#4
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Joined: Jul 2004
Posts: 11,332
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From: chicago
I can tell you first hand the blower upgrade is worth it . Been there and done it.
Twin carbs doesnt mean more fuel. A 600hp engine tuned right should use x amount of fuel whether it has a single 1050 or dual 850s .
I have twin 850s on my engines. This summer i had a linkage problem causing the secondaries on one carb to not open all the way. I lost 1 lb of boost because of that. Roots like lots of available air
Twin carbs doesnt mean more fuel. A 600hp engine tuned right should use x amount of fuel whether it has a single 1050 or dual 850s .
I have twin 850s on my engines. This summer i had a linkage problem causing the secondaries on one carb to not open all the way. I lost 1 lb of boost because of that. Roots like lots of available air
#7
Fuel atomization plays a roll in it also. The size of the jets required to allow proper fueling if using one carb would be so large it would essentially be like raining fuel into the motor.
8 smaller jets > 4 larger jets
Smaller droplets = way more gooder
8 smaller jets > 4 larger jets
Smaller droplets = way more gooder
#8
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Joined: Jul 2004
Posts: 11,332
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From: chicago
You can use it. I know they do make an adapter plate. I think youll find youll run out of carb before you run out of blower. Many guys have tried this since the 60s. Theres a reason 99 percent of 671 amd larger blowers run dual carbs. I woukd even prefer dual carbs on a 250 blower and its only about 60 percent of the size of a 671




