Sidewinder fuel distribution

[cjshaker]

Seeing how they're clocked differently just shows how much effort goes into research, design and development at the level of big auto makers. I can't even imagine how much effort, brainstorming and trial and error went into a simple design like those boosters. And for every effort that works out, there had to be a hundred or more that hit the trash can.

[Dumpling]

I think the "side" placement of the carb pad may have simply where it needed to be to equalize the runners of a dual-plane intake.  A quick check of the volumes of the two sides of the intake might verify this faster than measuring runner lengths.  Could you tape off the ports on the intake' s head flange, fill one side with water, and then measure the volume of water each half will hold?  Would that be a meaningful number?

[Clark Coe]

Measured and averaged the runner lengths (top of exit and bottom of exit) with a length plastic twine on my C6AE9424 / J Sidewinder intake. Not very scientific but I did find a pattern. Average length of right side (1,2,3,4) = 8.33". Average length of left side runners (5,6,7,8) = 7.30". I will scan and post my individual measurements tomorrow.   Is the Sidewinder considered a Medium Riser intake?


Clark

[427LX]

Those are fantastic flow numbers for a dual plane intake!

What was the reason for the bell boosters on the primary? Is that what cuts the flow from 780 down to 735 CFM?

[Drew Pojedinec]

One could assume that reduces flow.
Also an assumption the bell increases signal over a standard straight leg. While I’m assuming, that tip of the bell is at the same level as the vena contracta and should increase air speed all the more as it flows through.
I would think main flow on just the primaries would atomize better.
It runs the same throttle plates 172/173 as a 750/780 carb and similar Venturi.

I’m a very “well how does it run” kinda carb guy. I lack flow benches and dynos, etc so performance in vehicle is my main testing facility.

[RJP]

Along those same lines of fuel distribution Holley did something similar with the 3310-780cfm on OEM equipped 396/375 hp BBC. The primary boosters [down leg] had a small "finger" on the outside diameter of the booster supposedly to correct a [part throttle?] lean condition in a couple of cylinders on GM's dual plane high rise aluminum manifold. Drew, do you have any of those carbs for a picture reference?

Of course I do....
These are on the original 3310EH carbs, they are called Spivies.  If a person is interested, they can do the same thing with a small zip tie

IMG_0535 by Drew Pojedinec, on Flickr


I'm a huge fan of the EH carbs, they run really really well on everything, and they sure do clean up nicely.
The fact that I regularly find usable cores to restore for $60-$80 really helps things too.  Can't go wrong with them.
IMG_1132 by Drew Pojedinec, on Flickr

Thanks for posting the pic. I am a huge fan as well.  Metering seems to be very precise for a good overall performance and driveability as with most factory installed Holleys. Idle and transition circuits are responsive and seamless. But where do you find these cores for $60-80? Around here the Chevy guys think they are gold.

[Drew Pojedinec]

Last one I bought for $50. Being that I restore them fully, replate the hardware and linkage, and can strip and rechromate them, my standard for “usable core” is pretty darn low.

Mr rjp, if so inclined, take a later 3310-2 or other misc 750, knock out the straight legs, installed stepped down leg boosters and recalibrate to EH specs. You’ll be pleasantly surprised. They run better than the originals.

[e philpott]

My Chevy 3310 4150's have the adjustable low side air bleeds right in front of the air horns

[RJP]

Last one I bought for $50. Being that I restore them fully, replate the hardware and linkage, and can strip and rechromate them, my standard for “usable core” is pretty darn low.

Mr rjp, if so inclined, take a later 3310-2 or other misc 750, knock out the straight legs, installed stepped down leg boosters and recalibrate to EH specs. You’ll be pleasantly surprised. They run better than the originals.

Thank you kindly for the tip. I have an sorta off topic question. Have you had any leaking/weeping problems using the new style plastic bowl screw o-rings?