jeff baham
Well-Known Member
- Joined
- Aug 10, 2002
- Messages
- 1,257
what is the bore size of a .21 carb in inches please
.21 carb bore size
- Thread starter jeff baham
- Start date
Help Support Intlwaters:
Chris Wood
Well-Known Member
- Joined
- Jan 4, 2002
- Messages
- 3,473
.340 is a stock nova rossi carb
frank orlic made a .350 & a .370 carb
frank orlic made a .350 & a .370 carb
jeff baham
Well-Known Member
- Joined
- Aug 10, 2002
- Messages
- 1,257
thanks chris
Mike Larson
Well-Known Member
- Joined
- Apr 6, 2003
- Messages
- 927
I run the .350 here in the midwest with good results.. the stock nova carb rocks too... ( woods bellmouth, and mods).. interesting thread though... as in, are people having results with the .370... how, and where?...
Hi Mike, long long long time ago I was running a veco .19, with a .221 carb and a .035 thosands spray bar, I just counted all my .21 carbs, 31 in all, sizes range from .221 up to .430 with spray bars ranging from the ..035 spray up to .088 thos in the Rossi 80 carb I used to run in my seeducer .21 mono which ran very fast in heat racing, after about a lap when the motor heated up and it started to screaming those sweet RPM's. In my testing over many years, I am sure there is a coralation between how the engine breathes, stock or modified, compression, head clearance, carb size and spray bar size, and of course nitro content. Been running my EAGLE SG 80 with a .105 thos spray bar, .570 bore carb,(U can run bigger carbs and bigger spray bars when weather gets hot and humid, such as here in south west, FL. So is there a (standard .21 size carb), I have not found so.JM2CW
mobydickk
I agree with Dick, there is no one certain size for a .21 carb bore. Altitude has a lot to do with it as well. A .21 carb that does well at sea level will not run well at 3000 feet and might not run at all at 5000 feet.
Al Hobbs
Al Hobbs
My running & racing is all at sea level to 1,000'. I find that a .340 bore carb works best on my CMB greenie LS evo2's. Seems to be the best COMPROMISE FOR ME between speed, milling ability, & fuel economy. I also prefer to have a low speed needle adjusted properly. The larger the bore size, the more a low speed needle can help with throttle transitions & milling. Larger carb bores can give more top speed, but may not be the optimum size for heat racing (ie: driveability).
Charles Perdue
Well-Known Member
- Joined
- Oct 8, 2005
- Messages
- 2,177
Like most things, it is the combination that works. The carb bore, the size and design of the bell, the spray bar OD and the spray bar ID. Then is it the over all design of the fuel metering that makes a good working carb.
Some of the dimensions are critical to the thousanths of an inch.
A good working flow bench sure helps to get the carb in the ball park then there is a lot of testing to finalize it.
Thanks Mark for the words of confidence. We put a lot of time (years) into the developement and it shows.
Charles
Some of the dimensions are critical to the thousanths of an inch.
A good working flow bench sure helps to get the carb in the ball park then there is a lot of testing to finalize it.
Thanks Mark for the words of confidence. We put a lot of time (years) into the developement and it shows.
Charles
Last edited by a moderator:
Charles,
I know you made these 12-Zoom carbs for me awhile ago, but
I am starting to see what you are talking about above. THE COMBINATION
is the most important thing. I would like to thank you publicly for the dedication
that you have put into your carbs. I am currently running the 12, 21, 28, & 45 Zoom
Carbs and they sure are working well.
I hear that you are working on gas carb now?
I Appreciate All That You Do For The Hobby,
Mark Sholund
I know you made these 12-Zoom carbs for me awhile ago, but
I am starting to see what you are talking about above. THE COMBINATION
is the most important thing. I would like to thank you publicly for the dedication
that you have put into your carbs. I am currently running the 12, 21, 28, & 45 Zoom
Carbs and they sure are working well.
I hear that you are working on gas carb now?
I Appreciate All That You Do For The Hobby,
Mark Sholund
