Why does Edelbrock cut some plenum dividers and not others?

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LXguy

LXguy

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Hey All:

Been thinking of cutting the plenum divider in my air gap to see if i can squeeze some extra out of it.

Looking over the manifolds on Edelbrock's page, I noticed that the Chevy Air Gap is cut pretty serious straight from Edelbrock, and that the Ford 302 air gap is cut, but to a lesser degree (Ford 351W is not cut at all, same as Mopar).

Anyone have a clue why they might do it that way?

Anyone ever cut on their air gap?

Steve
 
True, at idle, the draw on the carb is light and the primaries work as intended, one side feeding one side of the intake.

When your at WOT, the draw on the carb and through the intake really starts moving. The cut in the divider helps balance. The older LD340 is like that. On older manifolds, the cut is big in order to provide a clearance for the carbs that were put out by Holley and Carter that were 3 bbl.'s. Normal primaries and 1 big huge door for the secondaries. The intake needs to be clearanced for these carbs.

I don't know why the dividers are the way the are on each intake, but I can only assume, that was found to be the best thing to do for the intake for that brand in the RPM band intended and the general performance intended for that intake.

(This 3 bbl. carb is the foreruning thought behind the spreadbores they used later. The T-Q is a race carb from birth, OE stocker second, adapted to a smog carb later.)

If your looking for some extra power out of the intake, you should look to a spacer. The engine combo should point the way to what would be best to use. What carb do you have on top now?
 
fwiw some ld340 intakes came with the notch and without the notch from the factory.

'I believe' it was the early ones that did not have the notch.

and.....only if the intake is the wrong design/too small plenum etc.. will a spacer help anything.

the notch all the way across is to try and squeeze more r's out of a dual plane, tricking the motor into thinking it has more plenum .jmo
 
Right now I've only got a 670 street avenger. I think I'm beginning to reach its limitations. I wouldn't notch the intake until I got a double pumper.

It'd be interesting to try. Don't want to trash a $250.00 intake if it doesn't work out. LOL

With the stock hood, I don't know if I have room for a spacer and an air cleaner that's of sufficient size. I'd like to get at least a 1/2" for the heat isolation though.

Steve
 
aluminum welds up easy, and costs lil to have done for something as small as that.jmo

and btw..it would work weather it was a dp or vac secondary that was tuned and had the right sec opening spring rate.
 
Gotcha, my reason for delay was that I think the carb is going to restrict before the intake wants more RPMs. However, if cutting is really additive to the mid-range, that's something else altogether.

Steve
 
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