El Camino Central Forum banner

1 - 15 of 15 Posts

·
Registered
71 El Camino SS
Joined
·
213 Posts
Discussion Starter #1
Hello,

Has anyone successfully (without mods) fit an Edelbrock Performer RPM (#7101), RPM Air-Gap (#7501) or Performer Air-Gap (#2601) intake manifold on your SBC 350 with an Edelbrock Performer/AVS2 or Holley 4150/4160 carburetor and a standard 14" wide air cleaner (3" tall air filter) under your factory SS hood (no cowl induction)?

Per Edelbrock:

Edelbrock Performer RPM #7101 and RPM Air-Gap #7501 manifold height specs: A-4.20", B-5.25", carb pad height 4.27" (A+B/2)
(.70" taller than original #2101)
Edelbrock Performer Air-Gap #2601 manifold height specs: A-3.72", B-4.92", carb pad height 4.32" (A+B/2)
(.27" taller than original #2101)

I just bought a Jegs dual plane intake #555-513000 (JEGS 513000: Intake Manifold for 1955-1986 Small Block Chevy 262-400, Dual Plane [Natural] - JEGS High Performance) A-4.29", B-5.31", carb pad height 4.80" (A+B/2)

Per Summit Racing, both the Edelbrock Performer/AVS2 and Holley 4150/4160 carburetors are 3.25" tall
(Carburetor Height)

Of course, air cleaner height will be dependent upon base type ("standard" vs "drop-base") but I'm just trying to get a feel for whether or not this is a no-go even with my factory SS hood. I know I could use a long straight edge to do some measurements and calculate clearance but I was hoping this post might yield some "real-life" experiences. Should have sent this post BEFORE I bought the manifold. Duh...

Thank you,

John
 

·
Premium Member
Joined
·
5,743 Posts
My setup is different. See my avatar,
I can suggest that as you start to build up, use clay to determine if you have enough room.
Example, should you determine that the carb will clear ok, due the following before putting on the air cleaner.
Put something flat about 16 inches round above the carb so nothing can fall into the carb.
Note that the carb is not likely to be centered on the hood.
Place multiple columns of clay on that plate where the distance looks the shortest.
Slowly close the hood, compressing the clay.
Open the hood and measure the compressed clay to see your distance.
Then measure your air cleaner.
Be sure to measure any air cleaner hold down hardware. You do not want to dent the hood.

In the example below, I knew I could get the air cleaner base on and have room.
So I put plastic across the top of the carb and put the base on top of that.
Then I cut a thin piece of Styrofoam.
I put the columns of clay on top of the Styrofoam, closed the hood smashing the clay and then measured the remaining distance.
My setup is different and my 3" X 14" air cleaner would not fit, even with a drop base.
Measure for yours.

 

·
Registered
71 El Camino SS
Joined
·
213 Posts
Discussion Starter #3
My setup is different. See my avatar,
I can suggest that as you start to build up, use clay to determine if you have enough room.
Example, should you determine that the carb will clear ok, due the following before putting on the air cleaner.
Put something flat about 16 inches round above the carb so nothing can fall into the carb.
Note that the carb is not likely to be centered on the hood.
Place multiple columns of clay on that plate where the distance looks the shortest.
Slowly close the hood, compressing the clay.
Open the hood and measure the compressed clay to see your distance.
Then measure your air cleaner.
Be sure to measure any air cleaner hold down hardware. You do not want to dent the hood.

In the example below, I knew I could get the air cleaner base on and have room.
So I put plastic across the top of the carb and put the base on top of that.
Then I cut a thin piece of Styrofoam.
I put the columns of clay on top of the Styrofoam, closed the hood smashing the clay and then measured the remaining distance.
My setup is different and my 3" X 14" air cleaner would not fit, even with a drop base.
Measure for yours.

View attachment 147353
Thank you Old Bear, I appreciate it. Great detailed info. So your 144 PowerCharger fits under your factory '70 hood with that short filter setup? Is it a SS hood or standard?

-John
 

·
Registered
Joined
·
222 Posts
It should fit.

My 71 El Camino has a factory/OE domed (non cowl induction) SS hood, 383 crate, air gap RPM 7501 intake and a Holley 4160 (0-80508) with a 3" tall 14" air cleaner w drop base and I don't have any issues. It fit with the functioning cowl hood prior to me swapping it to my Chevelle, which I think has even less clearance.
 

·
Premium Member
Joined
·
5,743 Posts
I am definitely not encouraging that triangular filter. The foam filter can get brittle, so change it every year.

The shape under the hood differs for the three stock hoods.
Aftermarket products also can have differences in their under-hood shapes/dimensions.
Add these differences, plus other variations and you see why the clay test may be important if you are close to hitting.
We don't want to dent the hood.

I was sure (as in surely very wrong) that I could fit a 14 inch air cleaner up into my cowl hood with the flapper door.
That Styrofoam circle got cut smaller to 14 inches after the first tests. Additional round blue layers were added to build a fake air cleaner that would prove me to be wrong.
I went to a couple car shows and looked at the stock ones. I found they were below the top of the fenders, and had rubber gaskets to create a seal to the underside of the hood.
It may be that my hardware shifts the center of the carb.
I also tried and could just barely put the 14 inch through the circle cut out in the hood.
Yet with multiple Styrofoam layers, the angle changes as the hood lowers.
Even my 1 * 14 inch early 60's Vette/GTO filter was not going to work.
It is possibly this is an after market hood. So far and I just haven't convinced my self to cut the underside of the hood.
All the 13 inch air cleaners said Ford, so I skipped the ribbing from that.
 

·
Premium Member
Joined
·
5,743 Posts
When measuring your height be sure to include the following to not have a bad surprise.
Thickness of the phenolic carb spacer (see below).
Thickness for the manifold to phenolic spacer gasket.
Thickness for the phenolic spacer to carb gasket.
Any raised ribbing or accents on the top of the air cleaner.
Those nasty hold down nut/wingnut/thingamabobbers and the length of the threaded piece for the hold down that is above the air cleaner.

The phenolic carb spacer goes between the manifold and carb. These reduce fuel boil over in the carb. This is especially true with our newer seasonal fuel mixtures. Rather than the corn alcohol, it is the butane and ISO-butane type additives. Phenolic spacers come in sizes from 1/4 inch to about 3 inches. Using an aluminum spacer will increase the heat transfer to the carb, which is undesirable.
 

·
Registered
71 El Camino SS
Joined
·
213 Posts
Discussion Starter #7
It should fit.

My 71 El Camino has a factory/OE domed (non cowl induction) SS hood, 383 crate, air gap RPM 7501 intake and a Holley 4160 (0-80508) with a 3" tall 14" air cleaner w drop base and I don't have any issues. It fit with the functioning cowl hood prior to me swapping it to my Chevelle, which I think has even less clearance.
Thank you lilbaggie!
 

·
Registered
71 El Camino SS
Joined
·
213 Posts
Discussion Starter #8
When measuring your height be sure to include the following to not have a bad surprise.
Thickness of the phenolic carb spacer (see below).
Thickness for the manifold to phenolic spacer gasket.
Thickness for the phenolic spacer to carb gasket.
Any raised ribbing or accents on the top of the air cleaner.
Those nasty hold down nut/wingnut/thingamabobbers and the length of the threaded piece for the hold down that is above the air cleaner.

The phenolic carb spacer goes between the manifold and carb. These reduce fuel boil over in the carb. This is especially true with our newer seasonal fuel mixtures. Rather than the corn alcohol, it is the butane and ISO-butane type additives. Phenolic spacers come in sizes from 1/4 inch to about 3 inches. Using an aluminum spacer will increase the heat transfer to the carb, which is undesirable.
Thank you, Old Bear. I'm looking at one of the Holley Brawler 4150/4160 carbs with billet metering block and throttle plate/shaft. I'll look into the phenolic spacer as I expect a warmer than usual SoCal summer. On that subject, what oil do you use? Conventional, synthetic or blended? What viscosity? My local O'Reilly doesn't stock the high zinc (1400 ppm) VR1 racing oil. I used to use Shell Rotella T4 15W-40, but I read the zinc content has dropped down to 800 ppm (from 1200) as they moved to a dual (API/CK-CJ) certification rating. I've been looking into the Gibbs "Driven" racing oils.

-John
 

·
Premium Member
Joined
·
5,743 Posts
One more thing to consider when hood clearance space is sparse.
The dropped bases for the air cleaner can help.
However, make sure the manufacturer says it will have clearance for HEI ignitions and Holley 4150 type carbs if you have them.
Otherwise, they may not drop down due to interference.
 

·
Registered
Joined
·
46 Posts
Hello,

Has anyone successfully (without mods) fit an Edelbrock Performer RPM (#7101), RPM Air-Gap (#7501) or Performer Air-Gap (#2601) intake manifold on your SBC 350 with an Edelbrock Performer/AVS2 or Holley 4150/4160 carburetor and a standard 14" wide air cleaner (3" tall air filter) under your factory SS hood (no cowl induction)?

Per Edelbrock:

Edelbrock Performer RPM #7101 and RPM Air-Gap #7501 manifold height specs: A-4.20", B-5.25", carb pad height 4.27" (A+B/2)
(.70" taller than original #2101)
Edelbrock Performer Air-Gap #2601 manifold height specs: A-3.72", B-4.92", carb pad height 4.32" (A+B/2)
(.27" taller than original #2101)

I just bought a Jegs dual plane intake #555-513000 (JEGS 513000: Intake Manifold for 1955-1986 Small Block Chevy 262-400, Dual Plane [Natural] - JEGS High Performance) A-4.29", B-5.31", carb pad height 4.80" (A+B/2)

Per Summit Racing, both the Edelbrock Performer/AVS2 and Holley 4150/4160 carburetors are 3.25" tall
(Carburetor Height)

Of course, air cleaner height will be dependent upon base type ("standard" vs "drop-base") but I'm just trying to get a feel for whether or not this is a no-go even with my factory SS hood. I know I could use a long straight edge to do some measurements and calculate clearance but I was hoping this post might yield some "real-life" experiences. Should have sent this post BEFORE I bought the manifold. Duh...

Thank you,

John
I just had a FiTech TBI installed on my 72 SS with the domed hood and a large diameter 4" tall air filter that has an unknown airgap intake and have no issues except annoying air flow sounds. I am going to add a different enclosed air cleaner like dual snorkel Camaro or retro batwing Cadillac type as it's not cool like flipping the air cleaner top on a quadra jet.
 

·
Registered
71 El Camino SS
Joined
·
213 Posts
Discussion Starter #15
I just had a FiTech TBI installed on my 72 SS with the domed hood and a large diameter 4" tall air filter that has an unknown airgap intake and have no issues except annoying air flow sounds. I am going to add a different enclosed air cleaner like dual snorkel Camaro or retro batwing Cadillac type as it's not cool like flipping the air cleaner top on a quadra jet.
Thank you Kevin,

-John
 
1 - 15 of 15 Posts
Top