Ted or anyone, your thoughts on running which spacer on a 306 with mummert heads and intake? any input in the matter would be most helpful. thanks..

1956 F-100 in the works.

Ted, I think what he is referring to is a tapered spacer from the large hole to small hole manifold, being placed upside down, so the smaller end matches the intake. Would that create an increase in velocity at that bottleneck to aid in low end torque?

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

Wayne.  Here is a summary of what was dyno tested on a pair of iron intakes.  On a ECZ-B four hole intake, the 2” four hole spacer had lower peak and average numbers than when using a 2” tapered carb spacer.  Transitioning into the intake at the carb holes does not seem to be the key here. Running that same intake without any spacers had lower numbers than what was seen using spacers.  The intake just likes spacers.

 

On an ECZ-B intake that had the carb holes slotted, the 2” tapered spacer outshined a 2” HiFlo (4 holes into 4 squares), a 2” Offy dual slotted, and a 1” HVH dual slotted spacer.  No spacer at all had the lowest values of all.  It would appear that it’s hard to go wrong with the tapered carb spacer design on the ECZ-B intakes.

Lorena, Texas (South of Waco)

John.  Thanks for the real world input.  Supercharging just seems to make its own rules.  What works for normally aspirated engines just doesn’t cross over cleanly to ‘blow thru’ stuff.

Lorena, Texas (South of Waco)

Here's a Quick Fuel 1" aluminum carb spacer that is for Holley 4150 type carbs. It may be what I'll go with for my build. It is machined with the 4 hole/square bore design and their comments about performance seem to be right in line with Ted's.

http://www.summitracing.com/parts/QFT-300-4150-1AL/

Rono

  Ron Lane,  Meridian, ID

Ted;

You asked for more input, and here's mine.  I tried a slotted front-to-back intake on my race car with the Paxton.  Ran .1 to .15 seconds slower with the slotted one compared to the stock F code manifold.  No other changes were made.  It uses the stock phenolic 1/2" 4 hole spacer under the teapot..

John - "The Hoosier Hurricane"

hi ted, does a 4 hole tapered adaptor ( large hole carb to small hole intake ) work better than a straight bore 4 hole adaptor and boring the intake holes to match the larger bore? does the venturi affect help the bottom end torque on a street stocker?

 lincoln/merc. y-blocks &mel's                                                               bucyrus, ohio.

Here’s my two cents worth.  Anyone else is free to comment.

 

That’s a yes for elongating the carb holes into slots.  With the slotted intake you can go either way, four hole or open but my particular choice in this case would be an open style carb spacer if simply choosing from these two designs.  Because maintaining a separation under the carb (true dual plane) with the supercharger isn’t as important as in a normally aspirated scenario, then reducing any restrictions under the carburetor by using an open spacer would have its advantages.  Another option that would help to smooth the transition going into the ‘slotted’ manifold and still maintain a true dual plane design would be a spacer with dual slots that matches the intake holes.  Here are some more pictures including the dual oval or slotted spacer.  All these spacers are upside down and viewed looking at their undersides.

  

Lorena, Texas (South of Waco)

Ted;

I think I know the answer to this, but to be more certain, here's the question; I plan on using the "B" manifold on a street, supercharged 331 cu.in. motor. So, would you elongate the holes into ovals and use a 1" spacer that was open or with holes?

Thanks,

Rono

  Ron Lane,  Meridian, ID

The ‘tapered’ carb spacers are available from several suppliers in a variety of heights.  HVH and Wilson are two companies that come to mind.  Lots of home shops with CNC machines are also now knocking them out.

Lorena, Texas (South of Waco)