What carb for 454

[6872xtc]

If the fuel filter wasn't ever over half way full, AND you said that it was running out of fuel when climbing a hill, I would go to the fuel pump first. As Wes said, the clear fuel filters can be a fire hazard.

Well, I would go back to the Edelbrock, too. (AFB clone, as Wes put it. And he's correct) then try an electric pump.

I have a mechanical pump from O'Reilly's on my 406 small block. It pulls hard up to 5600 and into the next gear. Maybe yours is weak? I have a rear mounted tank in a long bed. No helper pump.

 

[6872xtc]

It’s just a clear plastic, but when hot it only trickles, like big drops, but it maintains 5-6 psi, on the gauge. When I replaced the new tank sending units they had filters on them, so wasn’t sure where to put the inline? If I go qjet, I’ll probably keep the manual pump.

There's something wrong. Either the gauge, or the pump is just aerating the fuel.
Can you temporarily install an electric pump to feed the mechanical?

 

[77snowwheeler]

If the fuel filter wasn't ever over half way full, AND you said that it was running out of fuel when climbing a hill, I would go to the fuel pump first. As Wes said, the clear fuel filters can be a fire hazard.

Well, I would go back to the Edelbrock, too. (AFB clone, as Wes put it. And he's correct) then try an electric pump.

I have a mechanical pump from O'Reilly's on my 406 small block. It pulls hard up to 5600 and into the next gear. Maybe yours is weak? I have a rear mounted tank in a long bed. No helper pump.

Sorry bout the misunderstanding. When I had the Edelbrock it ran out hill climbing. The avenger that I have now does not run out, but I fear it’s having some problems. I’m curious how the clear filters might be a fire hazard. Because they’re plastic?

 

[77snowwheeler]

There's something wrong. Either the gauge, or the pump is just aerating the fuel.
Can you temporarily install an electric pump to feed the mechanical?

Actually yes. I have a line and switch already set up, because I had one before. That may not be a bad idea.

 

[Wes Harden]

Plastic is bad too. They melt if above the intake

 

[77snowwheeler]

Plastic is bad too. They melt if above the intake

Ok. I’ll change that.

 

[77snowwheeler]

Plastic is bad too. They melt if above the intake

Would you, recommend a qjet 850cfm? Also, do they have vacuum secondaries? And electric choke?

 

[77snowwheeler]

Would you, recommend a qjet 850cfm? Also, do they have vacuum secondaries? And electric choke?

JET Performance 36003: Quadrajet Carburetor 800 CFM Modified - JEGS

JET Performance has released a Quadrajet carburetor for Chevy & GMC cars and trucks with 396ci and larger modified big block engines. The carburetor is extensively reworked by increasing main well size and is balanced to assure top end high RPM fuel flow. Several circuit modifications are made...

www.jegs.com

 

[CT-BLAZER]

Why not go modern + run electronic fuel injection ?

Much easier to adjust parameters with a laptop than a mechanical carbureted system.

 

[77snowwheeler]

Why not go modern + run electronic fuel injection ?

Much easier to adjust parameters with a laptop than a mechanical carbureted system.

I was getting serious about that. At about 2000 my troubles would be over, but I’m not ready to plunge into that. It’s a huge amount of work, and I really don’t want to get into anymore serious work. They require me to put in tank pumps in, and I’m tired. The tanks have been down twice already.

 

[Wes Harden]

Qjets use vacuum to open the secondarys, but not a vacuum pot like a Holley.
I would do 850cfm for a big block. What's nice about a Qjet is it will give the engine only the necessary cfm it needs until it gets to it's maximum cfm. So if you only need 750 even if you have 850 available you only get 750

 

[6872xtc]

JET Performance 36003: Quadrajet Carburetor 800 CFM Modified - JEGS

JET Performance has released a Quadrajet carburetor for Chevy & GMC cars and trucks with 396ci and larger modified big block engines. The carburetor is extensively reworked by increasing main well size and is balanced to assure top end high RPM fuel flow. Several circuit modifications are made...

www.jegs.com

I personally wouldn't go with a Jet Performance one. I believe that I had found mixed reviews.
Sean Murphy, of SMI, called me before building my carb back then. Mine has been pretty good.
Electric choke should be available. Mine had it when I got it from an old C30.

 

[83ChevyK5Blazer]

Smi asks for a bunch of info and builds a qjet for your engine, elevation, and use. jet is a generic rebuilder.

 

[83ChevyK5Blazer]

My 750 came with electric choke, my core bbc has it as well

 

[CT-BLAZER]

I was getting serious about that. At about 2000 my troubles would be over, but I’m not ready to plunge into that. It’s a huge amount of work, and I really don’t want to get into anymore serious work. They require me to put in tank pumps in, and I’m tired. The tanks have been down twice already.

Yes, and it's still not right...... Unfortunately, most of todays technicians started after carbureted engines were out of production....


Body up, tank access is easy.

Good luck

 

[Blue85]

When I had the Edelbrock it ran out hill climbing.

They're pretty famous for that. I've seen trucks hung up on obstacles and they can't get off because the engine won't run at that angle.

 

[77snowwheeler]

Smi asks for a bunch of info and builds a qjet for your engine, elevation, and use. jet is a generic rebuilder.

I called, and Sean actually answered, and he is extremely awesome. He was very kind and patient. Helped with Troubleshooting some of my issues. I would use this guy 1000%, but he’s 17 weeks out. Unfortunately I’ll have to get something now. I have to have this running great, by the end of September.

 

[Chickntrk]

What avenger do you have? Street? Truck? Edlebrocks suck off road as you found out. I have been running holley truck avengers for years and have never had an issue but you do have to work with them to get them right

 

[folkenheath]

I am a big Holley fan, but I do not like the truck avenger. They got rid of some air bleeds to let it idle on a hill but it throws the fuel curve way off so its lean down low and pig rich up high.

A standard Holley with jet extensions will have good power on hills, but it won't like to idle on steep hills or it won't like large bumps.

EFI is the way to go, or a qjet second choice. I put EFI on my big block truck and I don't want to go back to a carb.

Some people run an inline pump with success, but an in tank pump is better.

I can help you select the parts if you need, carb, ignition, fuel pumps, efi, whatever you need, just give me a call. Big blocks rule!

 

[HankScorpio]

I am a big Holley fan, but I do not like the truck avenger. They got rid of some air bleeds to let it idle on a hill but it throws the fuel curve way off so its lean down low and pig rich up high.

A standard Holley with jet extensions will have good power on hills, but it won't like to idle on steep hills or it won't like large bumps.

EFI is the way to go, or a qjet second choice. I put EFI on my big block truck and I don't want to go back to a carb.

Some people run an inline pump with success, but an in tank pump is better.

I can help you select the parts if you need, carb, ignition, fuel pumps, efi, whatever you need, just give me a call. Big blocks rule!

I have the Edelbrock ProFlo4 on my big block. I bought it from @folkenheath and he installed his volcano in the intake. I have been driving the EFI for a week now and its outstanding. My other squares are TBI. I will not be going back to carbs, its not worth the hassles. If you know them inside and out then fine but for everyone that struggles with tuning carbs the EFI technology is there to move on.