Mikeywanted to know
The FS hand book is a winner. It errs on the side of caution. Theres nothing extensive on the 2v though. I haven't got the book yet. Maybee I be a bit more carefull on what I say.
Boy, did I think I hit paydirt last week. There was a discussion on 2305 series carbs way back somewhere which I remember, but the main piece was that it is a sequential carb, sort of a cut-down of the most popular 4160 550cfm vac sec for the 350, and a 4160 (part number 3310) 750 cfm 4-bbl vac sec, for the 500 2-bbl. Sounds like it's just the carb for us guys worried about too much carb for the cubes. Does any one know when it was canned, and how easy they are to find?
Mikey, I think the 2305 500 cfm is the best carb. It's basically half of the best V8 street strip carb ever made. It flows a true 354 cfm at 1.5" Hg, and half of its 221 hp capability is made on the first barrel. So long as the secondary comes in nicley, its the one to have. A Weber DGAS 38 would be a close match. Then a 465 cfm 4-bbl or 500 cfm simultanoues PN 4412 would be the second and third options. I believe the 390 cfm is too restricted in the venturi area, giving a very strong signal in both priamry and secondary circuits. On a six, which has great idle and off-idle vacuum, I'd shy away from it. Okay on a 170 cube V-6, but not on a bigger straight six. A 390 may be the 'ducks guts on a 140 Vega, 2 liter Pinto, 2300 Lima, 215 Buick or Rover 3500/TR7 V8, but the intake manifolds are nice and small, with good distribution. The 2V six has poorer fuel air distribution than those and way too much plenumb area where there is no downward flow to gain gas speed. But Mustangaroo has run one and I haven't. What makes me the expert?
Oh, if you want power levels and throad areas and venturi sizes, then just check lines 9 and 16 of the chart I set up here.
Back on to the 2305, then.
http://fordsix.com/forum/viewtopic.php?t=7015
Fittingly chaotic, but it's all there. Maximum power per barrel is on the right
From http://www.allpar.com/omni/testimonials.html
Another post http://www.225.ca/tech/jstk001.htm, from our brothers at theSlantSixSite:-
And from the last site, http://groups.yahoo.com/group/locost/message/829?source=1:-
And Xecute- if you can post the ideal venturi size, etc. numbers for an OZ 2V head, that would be really cool.
Is the Falcon 6 motor handbook a good resource for such calculations?
The FS hand book is a winner. It errs on the side of caution. Theres nothing extensive on the 2v though. I haven't got the book yet. Maybee I be a bit more carefull on what I say.
Boy, did I think I hit paydirt last week. There was a discussion on 2305 series carbs way back somewhere which I remember, but the main piece was that it is a sequential carb, sort of a cut-down of the most popular 4160 550cfm vac sec for the 350, and a 4160 (part number 3310) 750 cfm 4-bbl vac sec, for the 500 2-bbl. Sounds like it's just the carb for us guys worried about too much carb for the cubes. Does any one know when it was canned, and how easy they are to find?
Mikey, I think the 2305 500 cfm is the best carb. It's basically half of the best V8 street strip carb ever made. It flows a true 354 cfm at 1.5" Hg, and half of its 221 hp capability is made on the first barrel. So long as the secondary comes in nicley, its the one to have. A Weber DGAS 38 would be a close match. Then a 465 cfm 4-bbl or 500 cfm simultanoues PN 4412 would be the second and third options. I believe the 390 cfm is too restricted in the venturi area, giving a very strong signal in both priamry and secondary circuits. On a six, which has great idle and off-idle vacuum, I'd shy away from it. Okay on a 170 cube V-6, but not on a bigger straight six. A 390 may be the 'ducks guts on a 140 Vega, 2 liter Pinto, 2300 Lima, 215 Buick or Rover 3500/TR7 V8, but the intake manifolds are nice and small, with good distribution. The 2V six has poorer fuel air distribution than those and way too much plenumb area where there is no downward flow to gain gas speed. But Mustangaroo has run one and I haven't. What makes me the expert?
Oh, if you want power levels and throad areas and venturi sizes, then just check lines 9 and 16 of the chart I set up here.
Back on to the 2305, then.
http://fordsix.com/forum/viewtopic.php?t=7015
Fittingly chaotic, but it's all there. Maximum power per barrel is on the right
From http://www.allpar.com/omni/testimonials.html
Gary Howell's Rampage: The Rampage has had several carburetors on it. The one that I liked the best was the Holley 2305 series progressive 2bbl. Vibration destoryed several of them. The carb. on it now is a reworked factory 5200 series Holley, Barry Grant fuel systems did a stage 3 rebuild on it. They wouldn't give me any flow numbers on it, but it should be in the low 400 cfm range.
Another post http://www.225.ca/tech/jstk001.htm, from our brothers at theSlantSixSite:-
Another route to go if you have a modified engine would be the Holley 2305. The 350 cfm version should do quite nicely on a mild engine. The 500 would only be for more heavily modified motors. The 350 may sound like it's only 40 cfm smaller than the Holley 390 cfm 4 bbl, but it isn't. Holley tests its 2 bbl and 4 bbl carburetors differently. They use a 1.5" of Hg (mercury) pressure drop for 4 bbl, while 2 bbl carburetor flow numbers are generated at 3" of Hg. So the difference is actually much greater than the 40 cfm that the numbers indicate. There is a formula to convert between the two, but I don't have it handy. One other thing about this carburetor: It uses annular discharge booster venturis which help give a better metering signal. This lets you get the jetting closer to optimum without suffering bogs and hesitation. If I can stand to part with the money, I may try this in place of my 390 4 bbl to test the results. If not I'll try a Holley/Weber carburetor off of a Pinto or Vega.
Update! The Holley 2305 is no longer available. They didn't sell well and were discontinued.
And from the last site, http://groups.yahoo.com/group/locost/message/829?source=1:-
There was a question a few days ago about changing a Pinto from a Holley-Weber to a progressive Holley 2305. The Holley-Weber was listed as
having 180 cfm. According to my Holley catalog, the 5200 range from 230 to 280 cfm, depending on application.
There seemed to be some misconception about the 2305 as to their
configuration. At first glance they do look like the 2300, but the
throttle shafts are different. They are thru the short side of the Holley
base, not the long side, and they are available either as 350 or 500 cfm.
They are intended specifically for small 6 and 4 cyl applications, and they
do work. One could maybe pick up another 30-50 cfm on the 5200 series with
some judicious polishing, but the 350 would be a better starting place for
modifications.