The Stovebolt Site Forums The Shop Area Engine Shop 409 stuff again- Intake/Carb

So I never said it explicitly on here but I'm gonna keep the 409. However I decided to swap to Gas from propane solely for logistical reasons. This requires a carb swap obviously. I was going to just grab an Edelbrock but then someone said something about how the bolt pattern on the cast iron manifolds are different and I would need an adapter plate. Can anyone confirm this? My truck is at my parents house right now and I wont be there again till Saturday so I cant just walk out and measure.

This isnt a huge deal because I was considering getting an aluminum intake anyway. I found this one on ebay here: INTAKE MANIFOLD

It says it has a repaired "ear". What do you guys think?

Thanks

Aluminum Adapter plates are available at most FLAPS. Forget the Edlebrock go Holly. JMO

Martin - FLAPS??

Friendly local auto parts store.

I like that acronym The guys at the NAPA here are great.

And sorry Martin, I'm an Edelbrock guy. I'm not going to say they are better or anything because I don't have enough experience to say that. It's kind of a family thing. My dad wrenched with his dad and they always used Edelbrock and I did the same with my dad and will do the same with my son. We aren't racers or strip guys. We just have fun and we are loyal people. Its just a tradition.

Edelbrock carbs are poor-quality imitations of the Carter AFB. Find a real OEM Carter carb and don't look back. Yes, if you use an original style 4 barrel manifold, you'll probably need an adapter plate.
Jerry

There are two head/port styles on the 409s. The truck engine should have the small port/bolt pattern as the 348/lower HP 409s. The high HP 409 heads have larger ports and a different bolt pattern. You can still find performance manifolds that bolt up to the 348/409 small port pattern, Edelbrock 7158 for example. You don't need an adapter with those.

To check fitment, you may want to look at the head casting numbers, and consult: 409 Casting Numbers for the specifics of the heads on your engine.

The 409 had three different HP ratings with different 4-barrel carbs.

(1) base engine had a single Rochester 4-GC
(2) middle engine has a single Carter AFB
(3) high-output engine had two Carter AFB's

Quote Jerry (Hot Rod Lincoln) "Edelbrock carbs are poor-quality imitations of the Carter AFB".

Jerry is being too kind to the e-clone; they really aren't good enough to be called a poor-quality imitation. I would rather try to make a double log manifold and eight Rochester B's work than the clone! The clones are permanently banned from our shop.

Jon.

I have mentioned many times in these forums my dislike for Edlebrock carburetors. I’ve tried them on many engines (I’m a slow learner) over the past 20 years or so. Rarely with good results. I currently have two sitting on shelves in my tool room along with 3 quadrajets. I’d rebuild the quads before using one of the clones. The aluminum adapters are less than $50 and will adapt Edlebrock or Holly to your 409. Have fun with it.
🛠

Man. I had no idea that Edelbrock had such a bad rap. I feel like I must be a complete idiot and so ignorant that I can't tell that the ones I have aren't working well.

Anyway. I got my sister to get the intake casting number 3844472. I looked it up and all it says is 4bbl carb. I guess I'll just have to wait and measure the bolt spacing. Just means I can't have parts waiting for me when I get there tomorrow.

No one here is saying your an idiot. One thing you must realize here at Stovebolt.com everyone will share their opinions. So, if you don’t want to hear them don’t ask. There are thousands of Edlebrock carburetors out there that work just fine. Apparently you have had or have some. That’s good and I’m personally happy for you. What ever you choose is going to be your decision and hopefully you will be happily motoring down the Hiway in no time at all.

Spartan - as Martin mentioned, opinions are opinions, and are not meant as derogatory toward an individual; no offense was meant by me, and probably no one else.

If you are going to use an original intake with an aftermarket carb, the mounting gasket is as important as the bolt pattern!

Many of the O.E. manifolds have heat cutouts, and one needs to compare the gasket to the intake manifold, then the gasket to the carburetor flange to make certain there are no leaks. If you use an aftermarket intake, you can introduce other issues.

You also need to verify that the throttle plates do not hit the intake because the carb is larger (CFM) and has larger throttle plates.

One thing to always remember: if you use original parts, they are engineered to fit; if you use aftermarket parts, YOU assume responsibility as the engineer.

Jon.

I had heard about the throttle plates hitting. I was thinking I could just slap the intake in the mill and bore the whole area out to be an open square. I dont know if this is good or bad, I have seen some intakes like this. Is there a reason I shouldnt do this?

Also- I didnt take them as personal attacks per se. It just makes me feel like I must be severely incompetent if the general consensus is in opposition to my own.

Thanks Guys

The only way an open plenum under the carb will be an advantage is if you have a "single plane" manifold where all the runners to the cylinders meet in a common open plenum. Most OEM manifolds are "dual plane" where the two center cylinders on one side of the engine and the outboard cylinders of the other bank are fed from one side of the carburetor. The low end and midrange torque of a dual plane manifold engine is measurably better on a dyno than a single plane. Single plane manifolds are made to maximize top end horsepower for guys who never intend to run their engines below about 3000 RPM or so and don't care about low end torque.
Jerry

Thanks Jerry. That's stuff I always wondered about. It's OEM alright so I guess that means it's Dual Plane. And given that it's a truck manifold that makes even more sense.

Against the wind, still running against the wind, Bob Segar, heck of a song. I respectfully disagree with the AFB clone (Edelbrock) haters.....

I've had very good and reliable service & performance out of an Edelbrock 1406 4bbl bolted to an Edelbrock Performer dual plane intake manifold mated to an SBC. So much so that I've not rebuilt the Holley 600CFM stitting on my shelf (thanks Jerry).... Keep the crud out and they'll work good for you.

I'd venture to say the vast majority of 4bbl's running around my area are sporting the Edelbrock carb's and most will say they've had good service out of it.

IF the carb experiences hot fuel bubbling after shutdown Edlebrock has a spacer kit that'll help insulate the carb from manifold heat, like the spacer on the Stovebolt 6's does.
Otherwise the carb bolts up directly to the Edelbrock intake without any adapters, just a std gasket.

Swing away gents LOL....

Good luck with the 409.
Dave

Thanks for stepping in with me Dave.

Makes me feel better already that at least 1 person is on my side

"Hamburger tastes good- - - -until you eat a piece of prime rib". Those of us who remember how engines ran with the real Carter AFB's tend to be a little critical of the performance of the clones.
Jerry

It only matters if your taste is refined enough Jerry.

I've tried $1000/bottle wine and $10/bottle wine and they both taste like **** to me. 😁

Dave and Spartan - if you are happy, then I am happy

However, for comparison:

Competitive make (not Chevrolet) 1/2 ton pickup 6.5 litre (it is U.S. but this way I don't advertise the make) engine w/truck 4-speed and two 625 CFM Carters with solid linkage on Offenhauser intake manifold, approximately 450 HP. Engine was built with high performance factory street cam, and high performance factory street cylinder heads. Running points and condenser.

Performance: no hesitation from idle to W.O.T. in first, second, or third gear. No hesitation in four from 1000 RPM to W.O.T. (this is flooring the throttle).
Economy: pulling 16 foot trailer with JD 425 and JD 335 lawn & garden tractors at 55 MPH in rolling hills - 17 MPG
Economy: truck with no trailer 70 MPH interstate cruising - 22 MPG
Reliability - this is the 19th year they have been on the truck, and have not been apart since installation.

I will readily admit to tweaking the calibrations slightly.

You may make your own comparisons.

Jon.

Jon. I may have to stop off at your place for a weekend with a case of beer and have you teach me how to tune a carb. 😁

Be forewarned- - - - -Jon "tunes" an Edelbrock with a 3-lb. BFH!
Jerry

Spartan - Jerry is incorrect, I don't have a three pound hammer, its 8 pound!

But all joking aside, tuning a carburetor (assuming the carburetor is worth tuning ) is a matter of understanding the different circuits in the carburetor, and how each reacts to vacuum.

For the youngsters, if one thinks of a carburetor as a computer; then the camshaft is the computer programmer, and the engine vacuum is the program.

Regardless of what one reads in "Hot Rod" magazine, street performance does not necessarily mean terrible economy.

And some carbs just are not worth my time to try to do anything with As one ages, one learns one's most valuable asset......................is time!

Jon.