Anybody ever tried this little gizmo?

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No experience here, but it's hard to imagine accel pump shear plates helping a WOT 2-step launch. I think they would improve street/strip driveability, especially with a big carb, clutch pedal, and not much vacuum.

Grant
 
B3422w5 said:
My thought on this thing was that it might have the ability a tiny bit off the 60 foot via a crisper hit.
little help on the 60 foot always is worthwhile to an overall time slip.
BUT….. maybe it’s just a gizmo..lol
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I won’t give you a ❌ on this but I do disagree on this statement. I removed my 1.98 powerglide low gear last year to calm my car down. My sixty foots were 1.25-1.27 and the car ran low 6.0’s. I installed a 1.80 and now my sixty foots average 1.30-1.32 and my car run low 6.0’s. I think I may have made one front shock adjustment this year instead of every track or seasonal weather change.
 
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Isn't this akin to the B/RB screened intake gaskets from the waaay-back project 444ci Chrysler Power RB Dart project? Annular boosters work, even though they reduce the cfm of the carb, they make more power....but again, all-out drag rig vs hot-street/road-course will net different degrees of bennys.
Last, the only thing You can count on, is that You can't count on anything 100% of the time. There have been atomizing tricks and successful mods that did just that, & the engines fell flat with the finer droplets, & this includes some NAPCAR teams so....
 
Killer6 said:
Isn't this akin to the B/RB screened intake gaskets from the waaay-back project 444ci Chrysler Power RB Dart project? Annular boosters work, even though they reduce the cfm of the carb, they make more power....but again, all-out drag rig vs hot-street/road-course will net different degrees of bennys.
Last, the only thing You can count on, is that You can't count on anything 100% of the time. There have been atomizing tricks and successful mods that did just that, & the engines fell flat with the finer droplets, & this includes some NAPCAR teams so....
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If the finer droplets fell flat then there's likely a tuning issue causing it.
 
MOPARMAGA said:
If the finer droplets fell flat then there's likely a tuning issue causing it.
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Well, I'm sure those NAPCAR teams will pay You big $$$$ to solve it for them so......here's Your opportunity........
 
Newbomb Turk said:
That or the fact that those engines run at 220 plus degrees means an annular booster will atomize the fuel too fine and cause a power loss.
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Yeah I guess that would be true, I'm sure they've done more experimenting than I can think of .
I imagine larger holes & the annual booster banjos being made down leg style could help along with a very rough burr intake manifold & someway to get the intake colder
 
Killer6 said:
Isn't this akin to the B/RB screened intake gaskets from the waaay-back project 444ci Chrysler Power RB Dart project? Annular boosters work, even though they reduce the cfm of the carb, they make more power....but again, all-out drag rig vs hot-street/road-course will net different degrees of bennys.
Last, the only thing You can count on, is that You can't count on anything 100% of the time. There have been atomizing tricks and successful mods that did just that, & the engines fell flat with the finer droplets, & this includes some NAPCAR teams so....
Click to expand...
I wasn't speaking to NASCAR engines, since I know not much about that stuff (nothing) and there doing something completely different than a drag race engine
 
MOPARMAGA said:
I wasn't speaking to NASCAR engines, since I know not much about that stuff (nothing) and there doing something completely different than a drag race engine
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That's pretty much the point of My post. There's only one way to know for sure what works for Your combo, try it, put it on the track & work with it. It either flies or dies....
Or just do what somebody else has done that works, & accomplishes Your goals, and move on..
 
Killer6 said:
That's pretty much the point of My post. There's only one way to know for sure what works for Your combo, try it, put it on the track & work with it. It either flies or dies....
Or just do what somebody else has done that works, & accomplishes Your goals, and move on..
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Gotcha, yep you're right.
 
Killer6 said:
There have been atomizing tricks and successful mods that did just that, & the engines fell flat with the finer droplets, & this includes some NAPCAR teams so....
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Many reasons for that. Timing and Ignition strength play a big part.

In regards to what happens when you open the throttle rapidly:

The pump shot should never be used to cover over a hole in the fuel curve. The pump shot is necessary to fill the manifold with fuel to compensate for the fuel that condenses on the walls at Zero vacuum. When you snap the throttle open the manifold vac goes to zero basically, and the boiling point of the fuel is increased. The fuel chemicals that were in vapor form at idle vacuum, condensate and fall out of the vapor stream because those chemicals turn to liquid. The end result of all this is less fuel entering the cylinder so the mixture in the cylinder goes lean.
 
Hysteric. Do you have the MSV topic "Dyno time" Saved?
original url was
http:// motorsportsvillage.com/forum/viewtopic.php?f=6&t=9693
 
Hmm.....maybe but not under that title.Was that Donees engine where they swapped carbs and noticed that the engine preferred the piss and dribble ciruit of the 3 circuit dominator over the 2 circuit?
 
Hysteric said:
Many reasons for that. Timing and Ignition strength play a big part.

In regards to what happens when you open the throttle rapidly:

The pump shot should never be used to cover over a hole in the fuel curve. The pump shot is necessary to fill the manifold with fuel to compensate for the fuel that condenses on the walls at Zero vacuum. When you snap the throttle open the manifold vac goes to zero basically, and the boiling point of the fuel is increased. The fuel chemicals that were in vapor form at idle vacuum, condensate and fall out of the vapor stream because those chemicals turn to liquid. The end result of all this is less fuel entering the cylinder so the mixture in the cylinder goes lean.
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Yeah, most of us know what accel pumps do & why, & VV carbs tend to scare most folks(even tho' AVS's & even more so TQ's are).
In the NAPCAR case, I believe the physics involved was something along the lines of; ...super-speedways are restrictor plated, that means the intake is functioning at a relatively high depression all the time, keeping normal fuel droplets atomized wasn't/isn't an issue, the 'hyper' atomization actually took up more space & reduced the atmosphere volume in the runners....less air & needless over-atomization cost them power. At least, that's the gist of what I recall about that one particular example.
 
I am surprised nobody sees a major problem with the acc pump nozzle plate. It will affect distribution. Many production carbs had snivvies riveted to the booster to direct [ or re-direct more correctly ] airflow. These were muuuuuuuuuuch smaller than the 'plate', so goodness knows had bad that plate will affect flow/distribution. It also takes up quite a bit of area, so one would expect total airflow to be reduced, apart from the re-direction.
On well designed carbs, the acc pump squirt is aimed at the booster purposely to break up the flow....& atomise it.

However the above 'gadget' was designed & used by Carter decades ago.
Look closely at the pump nozzle on a CS TQ & the AVS Carter carbs used on Mopars. There is an air break in the pump nozzle that drags air with the pump shot to atomise the squirt.

Bottom line: something so simple & cheap would be in widespread use...if it actually worked.
 
Killer6 said:
Yeah, most of us know what accel pumps do & why, & VV carbs tend to scare most folks(even tho' AVS's & even more so TQ's are).
In the NAPCAR case, I believe the physics involved was something along the lines of; ...super-speedways are restrictor plated, that means the intake is functioning at a relatively high depression all the time, keeping normal fuel droplets atomized wasn't/isn't an issue, the 'hyper' atomization actually took up more space & reduced the atmosphere volume in the runners....less air & needless over-atomization cost them power. At least, that's the gist of what I recall about that one particular example.
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Vacuum aids vaporization so if you have lots of it in a restricted engine then yes it may not need more.

If the theoretical ideal AFR is 12.7 to 1 for max power then a 12th of the ingested charge is fuel. How much of that small amount can expand to crowd out the air as a percentage?
 
Hysteric said:
Hmm.....maybe but not under that title.Was that Donees engine where they swapped carbs and noticed that the engine preferred the piss and dribble ciruit of the 3 circuit dominator over the 2 circuit?
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I think so. I may have saved it, or some of it into a word file. I'll look later this week. Shame Ken took it down, but its understandable since he decided running the forum was not for him anymore.
 
The points of both the posts above are on the money - so to speak. The Holley 3310 for Chevy's 396 for example had snivies to balance booster distribution direction for that engine and intake.

As far as the percentage of charge, point is valid, but the mass quantity is different than the volumetric relationship. Stated another way, with the throttles near closed, there is low pressure (high vacuum) which aids the mixing of fuel droplets and direction of flow toward the valve that is opening. Some portion of fuel may even vaporize. As the throttle opens, the pressure difference is reduced. etc etc

I'd be more interested in experimenting with and understanding what BLP has come up with than the sheetmetal device.
My suspicion is that it may be useful for specific setups rather than a universal miracle product.
 
I would imagine these would make "squirter pullover" much worse. That is something the BLP squirter is trying to prevent.
 
Hysteric said:
Vacuum aids vaporization so if you have lots of it in a restricted engine then yes it may not need more.

If the theoretical ideal AFR is 12.7 to 1 for max power then a 12th of the ingested charge is fuel. How much of that small amount can expand to crowd out the air as a percentage?
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Water expansion volume, liquid to steam-gas, is 1,700×. The race fuel NAPCAR is using is something I don't have enough info on to guess, I suppose I could look up a generic pump gasoline figure out of a book, but it would be an inaccurate stab at best.
Suffice to say, the more liquid fuel that turns to vapor that turns to gas in the intake, the more air that is displaced...which is already exceedingly rare in this instance..
 
Bewy said:
I am surprised nobody sees a major problem with the acc pump nozzle plate. It will affect distribution. Many production carbs had snivvies riveted to the booster to direct [ or re-direct more correctly ] airflow. These were muuuuuuuuuuch smaller than the 'plate', so goodness knows had bad that plate will affect flow/distribution. It also takes up quite a bit of area, so one would expect total airflow to be reduced, apart from the re-direction.
On well designed carbs, the acc pump squirt is aimed at the booster purposely to break up the flow....& atomise it.

However the above 'gadget' was designed & used by Carter decades ago.
Look closely at the pump nozzle on a CS TQ & the AVS Carter carbs used on Mopars. There is an air break in the pump nozzle that drags air with the pump shot to atomise the squirt.

Bottom line: something so simple & cheap would be in widespread use...if it actually worked.
Click to expand...
You're sort of making the assumption that fuel is already distributed evenly without the plate. In some applications where the fuel is not distributed evenly (as is often the case in a dual plane manifold) there is the outside chance that the plate could actually improve fuel distribution.
When I tested the plate on the dyno I saw a loss in power. I attributed the power loss to a loss in airflow caused by the plate hanging over the venturi. I could be wrong about that. If I recall correctly it didn't change the air fuel ratio as read by the airflow and fuel meters or the o2 sensors in each header collector. The individual cylinder temps didn't change significantly either. Cylinder temps can be a somewhat reliable indication of fuel distribution but not gospel.
The plate did cover up a noticeable hesitation on quick throttle opening. I was able to cover up the same problem by increasing the accelerator nozzle size without the plate and without the power loss caused by the plate.
The plate was able to cover up the same hesitation with a smaller nozzle size. I suppose that could means it does it with less fuel. I can't confirm that for sure.
I might consider it in an application where I had a hesitation and traditional means to fix it weren't getting the job done. Or maybe in an effort to get maximum fuel economy. Never say never.
 
92b said:
The plate did cover up a noticeable hesitation on quick throttle opening. I was able to cover up the same problem by increasing the accelerator nozzle size without the plate and without the power loss caused by the plate.
The plate was able to cover up the same hesitation with a smaller nozzle size.
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There's a clue.
 
weedburner said:
No experience here, but it's hard to imagine accel pump shear plates helping a WOT 2-step launch. I think they would improve street/strip driveability, especially with a big carb, clutch pedal, and not much vacuum.

Grant
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Would you mind expounding on how it can help with a low vacuum signal? That might get my attention, since my truck has only about 6hg at idle.
 
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