It's called the Thompson PowerBlast Plate, made by Thompson performance.

I was turned onto this thing by another reputable Bumpsider here on the forum.

What it is, is a little brass contraption bent up and shaped to fit around the accelerator pump shot nozzles. It intercepts the shot, and fans out the gasoline into a mist rather than a straight liquid squirt. ( kinda like washing a spoon in the kitchen sink)

Here's a video of it.
https://youtu.be/_xTnQ9e-SIM

Obviously, that in itself is going to work better. And really, that's all it needs to do.

The main thing they market it for is improved throttle response. More akin to what Fuel Injection would be.

I can say that the throttle response DID IMPROVE.


Now, for what it is, I think it's way over priced. However, there is obviously some engineering behind it, and it is fairly high quality. Your not paying for the part as much as the labor and time to make it. Being an amateur machinist and fabricator, I was going to try to replicate it, but the time I would spend trying to make the same thing would cost more than buying one.

it's not something that you can't live without. The difference on my setup wasn't like night and day, but it is noticeably better.


Bottom line, if you got a few extra bucks, (40-50) then this thing might be worth checking out. It does exactly what it says it does, and I'm not ever taking mine back off, but I don't know if I'll buy another one either.

 

It makes sense. Finer droplets of gas will atomize easier and better with the airflow. Like trying to put a Holley 850 on a 260 V8. Lay too big of fuel droplets for way to slow of air speed. Finer droplets of fuel is also why Ford designed in the Annular Discharge Booster venturis in the Autolite 2100,4100, and Ford/Holley 4180.

 

I put one on **** truck and whoa! He has the Holley carb on his. I have another buddy with an Eddy on his, I'll be installing next week.
We aren't drag racing,but if we can get her outta the hole and accidentally get a little more economy the $40 is worth it.

 

I tried one on a Holley 4150 that has always had a hesitation from a standing start and it did nothing. Not trying to stomp on it, just accelerating gently. But tnothing else has worked either...changed squirters, accelerator pump, pump linkage and accelerator cam.

 

That's too bad. I reckon you have to fix the primary issues first

 

I tend to be a skeptic when it comes to gadgetry. I mean, if it works then why is it the carb manufacturer hasn't incorporated it already?

The gadget prolly makes up or masks existing carb issues.

 

It might work, but 60 clams for a piece of brass is a bit much I'm thinkin'.

 

I am very skeptical myself, I wouldn't have bought it if it wasn't for teach's recommendation. Like I said though it does actually work.

It Is indeed overpriced for what it is!

 

I bet a lot of gearheads are fabricatin' their own. One of the forums, somebody was skeptical, asking just how much fuel is used by the accelerator pump. The answer is, more than you might think, in stop and go driving. It's just got to be a factor for in town/city fuel mileage killer. Everytime ya hit the go pedal.

 

... post up a dimensioned drawing and let's see what happens if we DIY it.

 

Looks simple enough. They are just using a flow disruption technique to get better atomization. Small enough to get knocked out on my Sherline.

 

Interesting and fits right in to normal engine theory like the paper I wrote last year titled: Detecting Power Cylinder Input through Crankshaft Angular Velocity Analysis. I don't see any reason it wouldn't work or why you couldn't make one at home.

 

There is a way to find out how much fuel the accelerator pump uses:

Disconnect the lever, run a tank through and compare mileage with prior result.
Yeah, the truck will bog but you get the answer.

 

Doesn't the pump shoot out either 30 or 50cc's each time you start to press the pedal down?

 

On a Holley, with full pedal travel, yes.

Other carbs use different systems. Ed uses a plunger style thing with adjustable stroke.