478 Hemi upgrades question

[SoldierOfTheLaw]

I have a 478 Barton hemi that is currently topped with the Keith Black Marine dual quad intake (2531921) and Edelbrock 1404 (500cfm) carbs. I need to replace my intake manifold gasket and decided to make some upgrades since the intake and carbs have to come off.

I spoke with Ray Barton and will be using his intake manifold gaskets along with the Edelbrock 7524 intake manifold and a pair of Edelbrock AVS2 carbs.

My question is this, Since I am going from the Edelbrock Performer carb to the AVS2 can I use my existing throttle linkage and will the spacing be the same for the fuel lines?

After I get everything swapped out I will probably sell the replaced parts to offset some of the cost.

Thanks in advance,
Pete

 

[finoke]

I would think the first question to ask is if the new intake still has the marine intake spacing between carbs. I seem to remember there is some adjustability in the carb linkage. I did a Hemi cuda clone about a dozen years ago and since sold it. But I seem to remember the marine manifold carb spacing was different than a factory dual quad carb spacing. Maybe someone else can confirm that. BTW I'm just North of Philly. I see you are in SE PA?

 

[Hemirunner]

Carb spacing is farther apart with the marine intake. It will depend on what linkage you have and how it’s made as to whether or not it works with the Edelbrock intake.

 

[Runcharger]

Does Barton figure the Edelbrock intake will be much better than the Marine?

 

[6PKRTSE]

Agreed. The marine intake should be further apart spacing. Since yo mentioned that you were buying from Barton. Ask him to measure center to center and then measure yours. Edelbrock also had a progressive dual four barrel linkage set up that has always worked well with mine.

 

[lewtot184]

From what I see in the edelbrock catalog a 7524 will use afb type carbs due to the close spacing. I wouldn't use anything smaller than a 1407 carb. Keep in mind that stock street hemi carbs have the same throttle bore and venturi size as a 600 and they weren't big enough. 67 cheater carbs were the same size as 1407 edelbrock, but used the smaller air horn. Stage 3 wedge super stocks used the same size carbs as the 1407. I use two 600's on a ch28 on a 440 and they're not big enough, and you should make at least 100 more horsepower than me. If you buy carbs by a cfm rating you probably bought the wrong carbs.

 

[rickseeman]

I'm sure the linkage has some adjustment but not near that much. The Edelbrock 7524 has stock Street Hemi spacing. Much closer. Hopefully, you have a friend that can make you a longer turnbuckle if you are happy with your present linkage.

 

[Fran Blacker]

I'm sure the linkage has some adjustment but not near that much. The Edelbrock 7524 has stock Street Hemi spacing. Much closer. Hopefully, you have a friend that can make you a longer turnbuckle if you are happy with your present linkage.

Wouldn't a longer piece of threaded rod that goes between the front carb and rear carb linkage work? Surprised OP didn't run single feed Holleys?

 

[rickseeman]

Depends on his current arrangement. Assuming he has heim joints for ends, the best way is to make a longer center section out of aluminum rod. Have to buy a left hand tap though.

 

[SoldierOfTheLaw]

I appreciate all of the replies. When I had purchased this car the motor was already set up this way.

finoke - I am just outside of Doylestown, so you are probable pretty close.

Runcharger - I told him that its a street car, but that I want to maximize the power potential. He told me I could spin my motor to 7k easily and the Edelbrock would make more power and be better suited to my combo.

lewtot184 - When we were discussing carbs I didn't ask for a specific carb, rather asked for his suggestion. I "don't know what I don't know" and didn't want to assume anything since this area isn't my wheelhouse. He recommended the Thunder AVS2 800 cfm carbs and he will go through them and set them up for my motor.

All of the parts are in stock and my name is up on the board to get the carbs calibrated. I'll probably wait until I have the new manifold and carb's installed and then see where I'm at with the linkage. The first car's and coffee around here that I plan to attend is March 23rd, so I have some time to get it figured out.

I had the car dyno'd at Second Street Speed in Perkasie back in June and it did 440 hp / 465 tq to the wheels. After I get it swapped over I'll schedule another dyno with Bill and see where I'm at.

Thanks again to all that replied, I appreciate it.

 

[lewtot184]

I appreciate all of the replies. When I had purchased this car the motor was already set up this way.

finoke - I am just outside of Doylestown, so you are probable pretty close.

Runcharger - I told him that its a street car, but that I want to maximize the power potential. He told me I could spin my motor to 7k easily and the Edelbrock would make more power and be better suited to my combo.

lewtot184 - When we were discussing carbs I didn't ask for a specific carb, rather asked for his suggestion. I "don't know what I don't know" and didn't want to assume anything since this area isn't my wheelhouse. He recommended the Thunder AVS2 800 cfm carbs and he will go through them and set them up for my motor.

All of the parts are in stock and my name is up on the board to get the carbs calibrated. I'll probably wait until I have the new manifold and carb's installed and then see where I'm at with the linkage. The first car's and coffee around here that I plan to attend is March 23rd, so I have some time to get it figured out.

I had the car dyno'd at Second Street Speed in Perkasie back in June and it did 440 hp / 465 tq to the wheels. After I get it swapped over I'll schedule another dyno with Bill and see where I'm at.

Thanks again to all that replied, I appreciate it.

the 800avs is a good carb. i would consider a 1407 a minimum.

 

[Fran Blacker]

If going to spin your Hemi over 6500 rpm you need a oiling upgrade from stock.

 

[SoldierOfTheLaw]

The motor is already a complete Barton engine, so I am good to go in the RPM department!

 

[6PKRTSE]

the 800avs is a good carb. i would consider a 1407 a minimum.

For sure, I ran two 1407's dialedin on a little ole +.030 426 HEMI, and the car ran excellent with some tuning after bolting them on. Everyone was saying it was going to be too much carburetion. HEMI's love CFM. I currently have two 1050 Dominators on my 528 HEMI that is street driven.

 

[lewtot184]

For sure, I ran two 1407's dialedin on a little ole +.030 426 HEMI, and the car ran excellent with some tuning after bolting them on. Everyone was saying it was going to be too much carburetion. HEMI's love CFM. I currently have two 1050 Dominators on my 528 HEMI that is street driven.

Back in the day, 1970 I believe, I put some big carbs on my brothers street hemi; big difference over stock. There's no such thing as too much cfm. If there was such a thing nobody would use a supercharger! The problem is exposing too much venturi area too soon in the power curve. That's why I like velocity controlled carbs; you can have your cake and eat it to

 

[Bird 426]

This is probably the progressive linkage they were referring to. I have #1405's on my 440 Hemi with the #7524 intake. I am currently re-configuring my throttle cable stand, carb attach point and spring returns. This linkage can be mounted low or high on the carb shaft brackets.

 

[SoldierOfTheLaw]

Just an update. I talked to Ray on Thursday and my carbs are done and everything is ready. I'm planning to drive out to pick it all up hopefully early this week. The goal is to get it swapped out and on the road to wake up my neighbors on Easter Sunday, haha.

I'll update this thread with my progress.

 

[SoldierOfTheLaw]

I got it buttoned up and running this afternoon with the help of two good friends. Earlier this week I attempted the same and the Edelbrock suggested fuel line kit was complete junk that leaked horribly. So that got returned and I made a trip to A-1 Racing Products in Ivyland PA. Brad is the man, I showed him some pictures and he put together the AN fittings and supplied the required fuel line. No leaks, and it looks 100x better than that other crap I had originally purchased.

I'll retorque and heat cycle this a few times over the next couple of days, change the plugs / oil and it is scheduled for a Dyno next month at Second Street Speed in Perkasie.