RPM airgap with carb spacer?

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mshred

mshred

The Green Manalishi
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Hey guys,

Im currently running a stock edelbrock RPM air gap manifold. With me new 360 build in order to keep costs down i was planning on reusing it. Im going with a hydro roller cam, so im going to have to keep the rpms under 6500rpm (am i wrong?). A couple of the cam companies ive talked to told me that I could do up 6800rpm with a juice roller cam, but that I need more manifold to do that. Ive read about how good the air gap is (though I cant find the damned article if my life depended on it) but is there any benefit to be had with adding a carb spacer? Or how about milling the center divider? Will I hurt low end and gain no noticeable difference in the mid to upper rpm range?

interested to hear what you guys think and any experiences you may have had with this stuff

thanks
 
My Air Gap center divider is milled down 1/2" and i run a 1" wooden spacer,wish i ran the car before i did the upgrade but i'm certainly not going to complain with the performance...
 
what does milling down the center divider do exactly?

Id like to see some tests with a spacer to see if there is any improvement and worth the coin
 
I remember a magazine article that tested numerous intakes and the Eddy Air-gap had no problem at all pulling strong to 7000. It beat every single plane intake tested on power below 5000 and was within a few horses all the way to the upper 6's. I can't comment on modifying the center divider as I've never done it. On my 360 I have an Eddy Air-gap and tried a 1" 4 hole wooden spacer and it picked up some low end torque and didn't seem to affect top end hp as far as I can tell from the seat of the pants.
 
Milling the center divider allows the engine to draw off of the entire plenum volume instead of just half. Ever notice how the Air Gap for the small Chevy has the divider milled already..says alot doesn't it. The small mopar..THE best small block ever... !! If you are thinking of milling yours..try an open spacer FIRST before you mill, 1/4", 1/2' or 1" , that will give you an idea of how it will behave milled..besides..it's kinda hard to put it back once machined..
 
D-mailman said:
Milling the center divider allows the engine to draw off of the entire plenum volume instead of just half. Ever notice how the Air Gap for the small Chevy has the divider milled already..says alot doesn't it. The small mopar..THE best small block ever... !! If you are thinking of milling yours..try an open spacer FIRST before you mill, 1/4", 1/2' or 1" , that will give you an idea of how it will behave milled..besides..it's kinda hard to put it back once machined..
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Thanks for the explanation and good idea with the spacer first! I think I will try one out, maybe a 2" at most...or is that too much?
 
DarTT said:
Would you run the open spacer even if you were using a thermoquad?
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Only if it were made to work with a Thermoquad. They are spread bore and most spacers are square bore. As far as what type/size spacer you run it depends on the application and what your trying to achieve.
 
fishy68 said:
Only if it were made to work with a Thermoquad. They are spread bore and most spacers are square bore. As far as what type/size spacer you run it depends on the application and what your trying to achieve.
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Okay, I thought I would go with a spreadbore. I will be running a mild 340, a rebuilt 904 and an 8 1/4 with 3.55s. Its gonna mostly be a street/track car as I am really close to Road Atlanta. I am gonna be aiming at 400hp, maybe a little more.
 
DarTT said:
Okay, I thought I would go with a spreadbore. I will be running a mild 340, a rebuilt 904 and an 8 1/4 with 3.55s. Its gonna mostly be a street/track car as I am really close to Road Atlanta. I am gonna be aiming at 400hp, maybe a little more.
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Best be getting a 8 3/4 if you plan on going to the track with an 8 1/4 and over 400hp.JMO
 
Spread bores are EXCELLENT carbs for street/strip cars. Super responsive with those small primaries and huge secondaries when needed. The TQ is my favorite spread bore carb. Holley makes a good one. Quadra jet is ok but I don't like them as well as the TQ. The TQ's are plentyful and cheap enough. You can pick one up at swap meets for $25. bucks, get a couple for spare parts. You can run a TQ on a std. holley (4150/4160) flange with a spread bore open spacer/adapter. I ran one of those for years with NO issues. And put me down for the 8 3/4 ..yes, you WILL need that.
 
mikesduster said:
Listen to D-mailman.....He knows his stuff!!!!!! Especially heads and intakes!!!! I know 1st hand.
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Haha, sure sounds it:-D. Alright D-mailman. I'll be sure to run the TQ I have with a spreadbore adapter. Im gonna have to keep an eye out for a 8 3/4
 
Mshred - if a spacer helps you on a dual plane, you have the wrong intake. I wouldnt waste efforts buying a spacer or whittling. Find an M1 or a TorkerII.
 
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