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V-Stacks for a SU carb

Dadandson

Jedi Trainee
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I am in the process of designing and manufacturing velocity stacks for my 74 Midget. I can't find any that will accomodate air filters. Can anyone tell me what the extra hole in the carb is for? There are the two 5/16-18 holes for the air filter and the 1-1/4 center hole but I am not sure what the other hole is for and can I cover it up.
 
Onthe face of the carb, where the air filter currently mounts.
 
Do not cover that hole, it is an external air balance. Boy will that mess you up.
 
Yep, if you cover those holes, the pistons in the carbs will not operate correctly, causing you more trouble than you want.

Some others here, and on other boards have told that the stock air filter bases have a radius machined into them that work much better than most velocity stacks out on the market. Especially those cheapies that you see in the catalogs.
 
I apologize. They are correct. I was assuming that you were talking about the holes in the back of many air filters until I reread your post. I believe Jack has v stacks built into his filters.
 

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Jeff,
Do the round type air filters fit over these type stacks? Carb -- gasket -- stack -- breather/filter
 
healeyboz said:
Jeff,
Do the round type air filters fit over these type stacks? Carb -- gasket -- stack -- breather/filter

Yes, they do. I've got those stacks on a couple of cars fitted with round K&N filters.
Jeff
 
Bugeye58 said:
The longer velocity stacks are generally only effective for operation at, or near to, WOT.

wot is WOT?
 
WOT:

1) small furry rodent with disproportionately large teeth roaming the hills of scotland in packs, often preying upon large game, dogs that bark too much, and troublesome children.

2) acronym for Wide Open Throttle
 
thanks - what do small furry rodents have to do with Spridgets? Thought those applied to Rabbits?
 
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Yes as mention above that a vent hole for the carb, cover it up and the carb won't work properly, HS4s (MGB carbs) have two, HS2s have one. I made some custom ones in the past, I have a pic of them on my work computer, I'll try to remember to post them, if I forget, please email my work (on the website listed below) and I'll post. I started out with 3.5" aluminum round stock, cut each one about 2" long, then drilled them for the two mount holes, and vent hole, then radiused the front and matched them to the carb throat. This allowed me to use a K&N universal cone filters that just slipped over the 3.5' width, this design is some thing may of us have done on the race cars, I do a simular deal with the MGBs using thier stock velocity stacks

The first two pictures are of what I do with the MGBs and using thier stock velocity stack, and with the KN universal cone filter, which is so easy to install and take off, a truley 2 second job. The last picture is a look inside the Huffaker Bugeye race car carbon cold air box at it's billet stack, the pictures of the ones at works give you a head on look at a set of these.

If you choose to make some of these, sounds like you have some machining sources, I and my customer might be interested in buying some from you, if this design is what you are looking, we flow tested this design, and it's clearly the best flowing set up.
 

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As usual, slick.
 
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