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Re: Change in direction w/ carburetor
[Re: madscientist]
#2610964
01/23/19 12:13 PM
01/23/19 12:13 PM
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Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
BradH
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Taking time off to work on my car
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OP
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I guess my next question would be what led you to believe you didn't have enough booster gain.
It could be helpful if you did some searching on the Racing Fuel Systems web forum, in particular for flow test vs booster signal data that Mark Whitener ('jmarkaudio')has posted there and on other web sites over the years. Here's a LINK to one of the old posts on SpeedTalk where he provided information such as shown in the graph below:
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Re: Change in direction w/ carburetor
[Re: fast68plymouth]
#2610978
01/23/19 12:49 PM
01/23/19 12:49 PM
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Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
BradH
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Taking time off to work on my car
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OP
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I don’t think that’s the answer he was looking for  Such is life... EDIT: Anyone who's willing to pay all my R&D bills can have all my R&D data. 
Last edited by BradH; 01/23/19 01:30 PM.
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Re: Change in direction w/ carburetor
[Re: ccdave]
#2610981
01/23/19 12:56 PM
01/23/19 12:56 PM
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Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
BradH
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Taking time off to work on my car
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OP
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Those are all very nice however you may want to try a BLP main body from Dominic at Thumper carbs. You won't be disappointed. The BLP is the ultimate 4150 main body. I've asked for before & after test data on like-for-like venturi size & booster config comparing the BLP BX4 main body against the "traditional" HP-type 4150 main body, but have yet to see any. I've seen the claims by the carb builders using that style of main body. It's pretty simple IMO: if they ET & MPH better than properly-tuned carbs of the same config that use HP-style main bodies, that would tell me there's something to the design. Do they look cool? Yep. Do they look like they "should" be an improvement vs the older style designs? Yep Have I seen anything "real world" to justify making the switch? Still waiting...
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Re: Change in direction w/ carburetor
[Re: BradH]
#2611003
01/23/19 01:29 PM
01/23/19 01:29 PM
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Joined: Oct 2007
Posts: 4,205
New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,205
New York
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David Vizard (first? 40 years ago) suggested that higher atomization (as produced by annular) increases the volume occupied by fuel, which reduces the air volume. High atomization is best in heads with excellent CFM capacity. If the head isn't that efficient, larger droplets (normal booster) means more air volume.
Mixture strength, air:fuel
By weight 14.7:1
By volume (fully vaporized) 9,400:1
An obvious try-out:
Annular for tip-in and part throttle response, and smaller HSAB to reduce the effect at higher RPM?
Boffin Emeritus
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Re: Change in direction w/ carburetor
[Re: BradH]
#2611027
01/23/19 01:59 PM
01/23/19 01:59 PM
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Joined: Jan 2003
Posts: 30,989
Oregon
AndyF
I Win
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I Win
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Posts: 30,989
Oregon
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I don’t think that’s the answer he was looking for Such is life... EDIT: Anyone who's willing to pay all my R&D bills can have all my R&D data. I'll agree with that.
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Re: Change in direction w/ carburetor
[Re: AndyF]
#2611073
01/23/19 03:07 PM
01/23/19 03:07 PM
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Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
BradH
OP
Taking time off to work on my car
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OP
Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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I don’t think that’s the answer he was looking for Such is life... EDIT: Anyone who's willing to pay all my R&D bills can have all my R&D data. I'll agree with that. I'm typically someone who has shared everything. However, for the latest carb "stuff", I'm still trying to figure things out and don't want to go into it publically any more than what I've posted.
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Re: Change in direction w/ carburetor
[Re: fast68plymouth]
#2611159
01/23/19 06:16 PM
01/23/19 06:16 PM
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Joined: Sep 2014
Posts: 4,457
Washington
madscientist
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master
Joined: Sep 2014
Posts: 4,457
Washington
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I don’t think that’s the answer he was looking for No that helps. I forgot about that forum Brad pointed out. When I get some time I'll jump over there and spend some time reading. Thanks Brad. I never expect anyone to give it all up for nothing.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
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Re: Change in direction w/ carburetor
[Re: madscientist]
#2611633
01/24/19 04:14 PM
01/24/19 04:14 PM
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Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
BradH
OP
Taking time off to work on my car
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OP
Taking time off to work on my car
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Val-haul-ass... eventually
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Eventually, for better or worse, all the juicy (or gory) details will most likely come out.
Right now there are too many variables in play that I won't understood better until I can test the carbs on my car... which isn't running, yet.
I'm stuck with a bunch of hypotheses in the meantime, and my hypothesis "hit rate" might be about 50%, if I'm lucky.
FWIW, here's my baseline, a late-90's BG Gold Claw 1.425" v that's proved to be a nice balance between streetability and on-track performance.
Last edited by BradH; 01/24/19 04:15 PM.
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Re: Change in direction w/ carburetor
[Re: BradH]
#2611647
01/24/19 04:35 PM
01/24/19 04:35 PM
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Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
BradH
OP
Taking time off to work on my car
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OP
Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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Those are all very nice however you may want to try a BLP main body from Dominic at Thumper carbs. You won't be disappointed. The BLP is the ultimate 4150 main body. I've asked for before & after test data on like-for-like venturi size & booster config comparing the BLP BX4 main body against the "traditional" HP-type 4150 main body, but have yet to see any. I've seen the claims by the carb builders using that style of main body. It's pretty simple IMO: if they ET & MPH better than properly-tuned carbs of the same config that use HP-style main bodies, that would tell me there's something to the design. Do they look cool? Yep. Do they look like they "should" be an improvement vs the older style designs? Yep Have I seen anything "real world" to justify making the switch? Still waiting... Here's one of those things for which I may never have an answer: If the BLP 1.59" v BX4 body on the left was fitted with the same annular boosters as the modified Holley Ultra 1.58" v body on the right, would the difference in the main body design itself result in a quantifiable improvement?  
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Re: Change in direction w/ carburetor
[Re: justinp61]
#2611658
01/24/19 04:58 PM
01/24/19 04:58 PM
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Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
BradH
OP
Taking time off to work on my car
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OP
Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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I have the same BX4 main body with down leg boosters... It should look familiar... that's a picture that you posted which I cropped to show only the BLP body. 
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Re: Change in direction w/ carburetor
[Re: Dave Hall]
#2611674
01/24/19 05:18 PM
01/24/19 05:18 PM
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Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
BradH
OP
Taking time off to work on my car
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OP
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Just looking at them I would have to say yes. There are no interruptions (besides the boosters) in the bores to the left where the Holley looks like a yard sale on the top of it. Left also looks like a smoother transition from the booster to the plate. The throttle plate itself looks to have blind screws. What about these two 1.58" v HP-style bodies that both have .600" ID 12-hole annular boosters? Do you see 20 CFM difference in flow between them?
Last edited by BradH; 01/24/19 05:22 PM.
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Re: Change in direction w/ carburetor
[Re: BradH]
#2611676
01/24/19 05:19 PM
01/24/19 05:19 PM
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Joined: Oct 2003
Posts: 11,684
W. Kentucky
justinp61
I Live Here
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I Live Here
Joined: Oct 2003
Posts: 11,684
W. Kentucky
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I have the same BX4 main body with down leg boosters... It should look familiar... that's a picture that you posted which I cropped to show only the BLP body. You dog! lol
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Re: Change in direction w/ carburetor
[Re: BradH]
#2611689
01/24/19 05:36 PM
01/24/19 05:36 PM
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Joined: Jan 2003
Posts: 14,491
So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
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So. Burlington, Vt.
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The throttle plate itself looks to have blind screws. Throttle plate? Screws? On the left? It looks more like a main body sitting on a table to me.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
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Re: Change in direction w/ carburetor
[Re: justinp61]
#2611694
01/24/19 05:39 PM
01/24/19 05:39 PM
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Joined: Jan 2003
Posts: 14,491
So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
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So. Burlington, Vt.
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I have the same BX4 main body with down leg boosters on my pump gas 434 small block and have wondered if annulars would be better for my street/strip use.
My carb started as a Bigs 950HP, if I can come up with a four corner idle 1 3/4" base plate I'm thinking about building the 950 to test at the strip against the BX4. I’m sure Summit will happily take your cc number and send you something suitable.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
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