unjunking the quadrajunk

[HotRodPC]

2 barrel Bill must have been an old timer, like the guys that would run a high decked Chevy 6 truck motor...... Those guys knew that HP is only a number and that torque wins races. The only problem here is that setup is as bad as a Holley, you won't drive past many gas stations.

He was for sure an old timer or old schooler at least. This was in a 65 Chevelle.

 

[HotRodPC]

Here's a question, (not being a smart ass but, maybe a *******) anyone run a Quadrajet on a BBC?

Yes, I have a Qjet on my 454. It happens to be a 305/350 Carb and works just fine. Most Qjets are 750 or 800 cfm. The metering rods is what determines the amount of fuel it can dump into the intake. Just because a carb has the ability to pull 750 or 800 cubic feet of air per minute, doesn't mean it does. And engine can only suck or vacuum in so much air. So if it's a 750cfm and the engine can only bring in 500cfm, then that's all that'll go through the carb even though it is capable of more.

 

[SirRobyn0]

A slice of raisin pie sounds like a punishment. Lol

I like raisins but raisin pie doesn't sound good to me either lol

Have to say the title of this thread upsets me. Quadrajunk? Really? It's one of the most versatile carbs ever made. And, "Holleys aren't reliable and not great for the street." Total BS on both counts.

It's the bad mechanic who blames his tools, or in this case, his engine parts.

If you want to start a thread asking for help, how about trying, "I'm having trouble with my carburetor".

Wow a little touch are we. He's had some on going carb issues, can we cut him a little slack?

 

[HotRodPC]

Have to say the title of this thread upsets me. Quadrajunk? Really? It's one of the most versatile carbs ever made. And, "Holleys aren't reliable and not great for the street." Total BS on both counts.

It's the bad mechanic who blames his tools, or in this case, his engine parts.

If you want to start a thread asking for help, how about trying, "I'm having trouble with my carburetor".

I totally agree with this. The Holley's were NOT reliable back in the day. The tended to leak alot after sitting for not all that long of a time, where Qjets right off the shelf after being used and put on the shelf for 2 years, still worked and didn't leak. Holley's also blew out power valves with one minor backfire. They sure didn't hold adjustment well. Seemed I had to adjust mine with ever tank of fuel. OK not that often, but still, fairly often. Those the were the very common 600 cfm Vac secondary 1850-X list #'s and the 750 Vac secondaries and all the double pumpers. HOWEVER, today Holley does have some fairly reliable cards. Like the Truck Avenger for example, I've heard is a good carb. I know a guy running one and he has no issues at all and it's holding adjustment just fine for 2 or 3 years now.

 

[HotRodPC]

I'll add about the old non relaible Holley, the good was, the sky was the limit for jetting and ability to adjust floats on the fly with the engine running and not having to disassemble was a racers dream. They were race friendly for certain, just not what I'd want on my daily driver that I'd expect to not have to work on all the time.

 

[idahovette]

Agree with HOTRODPC. The older Holleys were good as long as they were WOT. I have a Quadrajet on my BBC Chevelle runs pretty good, 13.75 ET but will pull 17-18 mpg at 65-70 on the road. Not bad for 3.31 posi through the mufflers.

 

[DoubleDingo]

Have to say the title of this thread upsets me. Quadrajunk? Really? It's one of the most versatile carbs ever made. And, "Holleys aren't reliable and not great for the street." Total BS on both counts.

It's the bad mechanic who blames his tools, or in this case, his engine parts.

If you want to start a thread asking for help, how about trying, "I'm having trouble with my carburetor".

He's young and doesn't take advice or suggestions well. Add to that he's probably looking to do a click bait thing.

 

[DoubleDingo]

Here's a question, (not being a smart ass but, maybe a *******) anyone run a Quadrajet on a BBC?

If I had a big block I wouldn't consider anything but a q-jet.

 

[broketiredugly]

lots of old busses and dump trucks, etc , were fitted with vac secondary holleys. they ran all day, every day without hiccup. some ran through oil bath air cleaners, had governors attached, had twist pull hand throttles for the pto (to run at a constant low speed for long periods of time) . these were installed on the engine during the build process from the factory. why were they selected for this application??

 

[broketiredugly]

Yes, I have a Qjet on my 454. It happens to be a 305/350 Carb and works just fine. Most Qjets are 750 or 800 cfm. The metering rods is what determines the amount of fuel it can dump into the intake. Just because a carb has the ability to pull 750 or 800 cubic feet of air per minute, doesn't mean it does. And engine can only suck or vacuum in so much air. So if it's a 750cfm and the engine can only bring in 500cfm, then that's all that'll go through the carb even though it is capable of more.

2bbl bill had an understanding of flow. a 2bbl maximized per engine build is always better than a 4bbl for simplicity sake alone. its only when you build for more hp at higher rpm that the 4bbl starts to outshine. at what point do you lose velocities at low rpm and at what point do you suffer from not enough flow at high rpm? those are starting points for deciding which intake / carb for your application.

 

[82sbshortbed]

The reason i ask is i have a almost new Quadrajet level 2 from national carburetor that i jyst took off the 305. My BBC has an Edelbrock carb on it. Came with it already on. I dont know what model the Edelbrock is.

National carb says there's a difference between the sbc and BBC quads but I can't tell. I'm sure mine is for sbc because that's what a told the guy I had when I bought it. Got level 2 because I had intake and hedders that I was putting on it.

http://www.nationalcarburetors.com/quadrajetsperformance/qje.aspx

I'm wondering if it's better than the Edelbrock carb that's on it?

 

[DoubleDingo]

2bbl bill had an understanding of flow. a 2bbl maximized per engine build is always better than a 4bbl for simplicity sake alone. its only when you build for more hp at higher rpm that the 4bbl starts to outshine. at what point do you lose velocities at low rpm and at what point do you suffer from not enough flow at high rpm? those are starting points for deciding which intake / carb for your application.

And cam & heads to match

 

[DoubleDingo]

The reason i ask is i have a almost new Quadrajet level 2 from national carburetor that i jyst took off the 305. My BBC has an Edelbrock carb on it. Came with it already on. I dont know what model the Edelbrock is.

National carb says there's a difference between the sbc and BBC quads but I can't tell. I'm sure mine is for sbc because that's what a told the guy I had when I bought it. Got level 2 because I had intake and hedders that I was putting on it.

http://www.nationalcarburetors.com/quadrajetsperformance/qje.aspx

I'm wondering if it's better than the Edelbrock carb that's on it?

I bet with a metering rod and jet swap, along with the correct APT setting, and getting air flap adjusted properly for WOT, it would run just fine on that big block.

 

[broketiredugly]

And cam & heads to match

yep, thats why i said its a starting point.

 

[broketiredugly]

I bet with a metering rod and jet swap, along with the correct APT setting, and getting air flap adjusted properly for WOT, it would run just fine on that big block.

im betting the same. at a couple hundred corrected HP, it aint pullin much more air on top than a smallblock. big gain would be on bottom,,,,,,,,just a guess.