carb question-Edelbrock or Holley

[trevmountain]

Looking at buying a new carb and need some advice. It will be going on my new big block I just had built for my K30. It's a 500 hp motor and I use it for hauling tooling around and light off roading. Just wondering about which carb to go with. I have been leaning toward the Holley Street Avenger 770. I want to get the best mileage I can. Don't know much about carb's so any and all advice is appreciated.


Thanks

 

[Corey 78K5]

Quadrajet.

 

[trevmountain]

How come Quadrajet?

 

[big pappa b]

Quadrajet.

Not a fan. Harder to tune. Many more moving parts and things to replace. Holleys are simple

 

[Corey 78K5]

Because they work and are superior for off road use when compared to a Holley or Edelbrock. They wont flood out while the others will with out modification, and even then they are a pain. Most of the guys still running carbs are still running the Qjet for good reason.

 

[Bowtie85]

Got a Holley 670 street avenger on my k20, works great. Also put a 770 on the 383 in my Beaumont, no complaints either. Great carb, go Holley

 

[tRustyK5]

Q-jet

Better economy, better part throttle response, better performance off road, and they stay tuned (unlike a Holley)

Edelbrock's just suck, unless flat smooth pavement is all you'll see.

They don't call the Q-jet "Hillbilly fuel injection" for nothing. Look into JET or SMI for a great carb built for your motor.

 

[Ned Kelly]

Q-jet. As mentioned, they stay tuned for a long time. Great for dd and offroad. OEM reliability. Find a May 2001 FourWheeler mag carb comparo and they rated Q-jet as the best carb.

 

[ryoken]

Q-jet

Better economy, better part throttle response, better performance off road, and they stay tuned (unlike a Holley)

Edelbrock's just suck, unless flat smooth pavement is all you'll see.

They don't call the Q-jet "Hillbilly fuel injection" for nothing. Look into JET or SMI for a great carb built for your motor.

as mentioned X eleventy... not even a comparison on a stock to mild mill....

 

[K5_Fla]

I know everyone hates Edelbrock - but I have a 1406 and it's prefect. Cheap and easy tear down and clean/rebuild. I installed the off road needles and I have no issues.. but I'm also not hard core "upside down" rock climber or anything... pretty flat here in Florida

 

[ryoken]

it's nothing against Edelbrock per se, after all, it's not their design... it's a freakin Carter design from WAY back.... and, the design sucks compared to a quad...... I see ton's of Weber's version of the same thing every day...... when it works, it works ok, but the design has WAY more fail/wear/clog points than a quad....

 

[63chevyll]

used an edelbrock Q-Jet on a v8 Jeep a few years ago and it worked very well,

Just put a Holley Truck 670 on my Crew cab and works good but I liked the Q jet better.


but Q jets are a pain to re build and alot of the throttle shafts are worn out.

 

[blazinzuk]

q jet from SMI or Jet or anywhere else that rebuilds them, basically a brand new carb. I know I called SMI once and they said they would need all my engine specs the altitude I lived at and what my torque converter stall was.

Edelbrock super simple, not good quality control. Even with off road needles and seats they suck on steep hills ( like off road stuff) more so if the hill has some bumps or ruts you may need to hit with some speed.

Holly truck avenger is better than before and it would be my second choice after a q jet, but once again all the tuning is up to you. You will lose a mpg or more to a q jet.

Both the Edelbrock and Holly are square bores and the q jet is spread bore meaning when driven with a modicum of sanity you will pick up mileage on the q jet to the other two

You won't lose any HP to a q jet. They are a bit more complicated but hey if you can read you can tune one. A carb is a pretty simple piece anyway its not like its some mulit carbed sidedraft updraft upside down hooligans its a single carb. Its still pretty easy to tune

 

[big pappa b]

used an edelbrock Q-Jet on a v8 Jeep a few years ago and it worked very well,

Just put a Holley Truck 670 on my Crew cab and works good but I liked the Q jet better.


but Q jets are a pain to re build and alot of the throttle shafts are worn out.

I know where you can get one...

 

[63chevyll]

Lol, I actually became attached to the q jet you have. It ran flawless on my big block

 

[wazzabie]

Elderbrock had made some newer qjets up untill around 2001? Sometimes I see them on ebay going for big bucks.

 

[trevmountain]

Well that is interesting because that's what's on the truck now is an old Edelbrock Q jet.

I recently pulled my 454 out of my K30 and had it rebuilt and dyno'd. My whole question regarding the carb is based on the dyno. I actually was just going to stick with the Q jet but as part of the dyno process the shop used a Holley 750 double pumper that they use as a first on all there dyno's simply because they know it works and it allows them to iron out any other problems that may arise before running the dyno test with the customers own carb.

So after the results the old Edelbrock q jet came in with 15 less horsepower and was running alot richer than the pumper as well.

I witnessed both running and the pumper certainly had much better throttle response and just seemed to work better all around. I really have no idea how old the Q jet is and I'm sure that it needs to be rebuilt, jetted and tuned for my application but I myself and my engine builder didn't have any idea where to get parts to do this or how to do this so I just assumed that going with either a Holley similar to the pumper or a newer edelbrock was my best option.


It sounds like most really like the Q jet style and if that's the case what should I do with the one I have? Is it just as simple as getting the right parts for it or do you recommend I still go with a rebuilt one from Jet or another company similar?

Here is a pic of my carb

Thanks

 

[blazinzuk]

I am going to send my carb ( same as you have) for my dually to SMI more than likely to have them go through it. When I get closer I will talk to Jet and everyone else too.

You have a shop in Jackson do it?

If so they have probably tuned the holley for at least elevation, while the q jet may not have been.

Like I said before, I have know guys that have gone to a squarebore Holley or Edelbrock and they lose at minimum 1mpg. I know one guy on his small block powered Jeep that lost 3 mpg, and he messed around with that Holley for a year before putting the q jet back on. On the dyno the holley was worth about 10 hp for him. But 3 mpg was to heavy a penalty to pay.

 

[63chevyll]

Maybe someone else knows for sure. I I remember reading a long tone ago that the edelbrock has holly jets.

I have never jetted a Q jet so don't know, but maybe the aftermarket did put holly jets in them.

It's my experience with a qjet, if they're rich its time for a rebuild.

I don't want to talk you in or out of getting a holley. Just depends on how you want to mess with it

 

[folkenheath]

So does that mean that you didn't replace the heads to fix the oil consumption problem? You had to get a full rebuild? What's the scoop there? I was curious since that thread died, it's still out there...

As for the carb, you have to decide, a double pumper will certainly have more throttle response and can be more finely tuned for power, but the qjet will probably get better gas mileage and will run better on hills at angles. It all depends on what you prefer, it's a tradeoff.

I am a Holley man because I like power and tuneability, but I do enough wheeling I couldn't deal with the engine dying on steep hills when I was trying to maneuver, so I ended up getting the FAST EZ-EFI, it bolts right on your carbed intake and it works awesome, I don't want to go back to a carb. I still have a carb on my street/strip car and I get tired of getting fuel on my hands and dumping it everywhere when I need to jet up for the cold weather, etc. Which it will run fine without jetting up but when you are trying to tune for ET it is much easier sitting in the cab with a computer or handheld.

I will say one thing, as much I as I love Holleys, do not put a truck avenger on a 500 hp Big block, I tried it with a 770TA on my truck, and tuned the crap out of it, jets, cams, squirters, acc pumps, etc. The problem is, in designing the TA carb they eliminated the high speed air bleeds to keep the circuit from dumping fuel in at angles. What this does is change the shape of the fuel curve, so pretty much the carb will always be lean at low RPM and rich at high RPM. After a lot of tuning, my truck ran OK, but didn't run crisp at RPM and didn't have the power it should, it would idle on a hill though! Luckily Holley has excellent customer service, they traded my my TA for a reman Street avender and the truck ran a ton better, I still tuned it a little better yet, but it was a night and day difference. However, then the truck would die on steep hills and I would have to keep revving it up to keep it running or it would go pig rich and die.

With my FAST system, it has the power and response of a double pumper, the fuel efficiency of the qjet, and it doesn't care what angle it's at or how bumpy it is, it runs good all the time.

Theres my info, hopefully it helps you decide.