[LEROYDOZOIS]

currently atm i have a eddy 1405/1406 on my 85 454

ive been reading all over the internet that the qjets will beat mpg out of the ball park no matter what you do/tune to other carbs.

summit has a sale on the reman qjets right now so im kinda kicking it around to maybe buy one.

im hopeing to hear good about reman carbs but id rather ask then to spend $280 on a headache =[ and for this matter, im not sure summit offers a qjet for my no emissions carb with a manual choke set up ( i changed a few things )

i think the qjet will fit on my performer intake but i havent looked too far into this all

i do love my eddy carb, at part throttle putting up a hill ( no load ) i get 15.5 afr and wot drops down to 10, its a tow truck so im not gonna tune wot..

also getting 8 mpg towing our 4000 lb boat and 8 mpg daily driving so it seems its rather efficient

[oldbogie]

Originally Posted by LEROYDOZOIS

currently atm i have a eddy 1405/1406 on my 85 454

ive been reading all over the internet that the qjets will beat mpg out of the ball park no matter what you do/tune to other carbs.

summit has a sale on the reman qjets right now so im kinda kicking it around to maybe buy one.

im hopeing to hear good about reman carbs but id rather ask then to spend $280 on a headache =[ and for this matter, im not sure summit offers a qjet for my no emissions carb with a manual choke set up ( i changed a few things )

i think the qjet will fit on my performer intake but i havent looked too far into this all

i do love my eddy carb, at part throttle putting up a hill ( no load ) i get 15.5 afr and wot drops down to 10, its a tow truck so im not gonna tune wot..

also getting 8 mpg towing our 4000 lb boat and 8 mpg daily driving so it seems its rather efficient

I don't think the cost and effort to put a Q-Jet on this will be justified by the result. The Q-jet does very well where cruise can be maintained on the primaries at moderate RPMs, when you are in it deep enough to trip the power enrichment and or the secondaries the mileage goes down quickly. The Edlebrock carb is the old Carter AFB/AVS design which shares many of the high efficiency features of the Q-Jet these being the primary ratio is controlled with metering rods in the jet. So depending on how many steps or tapers are on the rod the mixture can be more tightly controlled in the cruise range. The rod also controls the power enrichment from its bottom step. This compared to the Holley which essentially has only two steps a fixed jet for main metering across a wide RPM range and a off or on diaphragm valve for power enrichment. Still when carefully set up the Holley can come might close to the efficiencies of the Q-Jet or Carter/Edlebrock.

I have a friend with a 1970, 3/4 ton, 454 powered Chevy with a TH400 that he uses to tow his boat. It had a worn out Q-Jet; he went through a bunch of reman Q-jets none of which worked properly and one blew an ocean of gasoline all over the engine room, thankfully no fire, but the kind of thing that puckers your gonads. I finally talked him into a spread bore Holley from Summit. It bolted right on, ran super fine out of the box, he wanted me to tune it, I drove the truck around town and up and down I-5 for a few miles and brought it back to him telling him I doubted there was anything I could do that would make an improvement he could feel or measure. The mileage is super close to what the original Q-Jet gave before it wore out, maybe a half mile MPG less. One can by a lot of gas at that rate against the cost of finessing this toward better. So we let it be.

Bogie

[cobalt327]

Originally Posted by LEROYDOZOIS

currently atm i have a eddy 1405/1406 on my 85 454

ive been reading all over the internet that the qjets will beat mpg out of the ball park no matter what you do/tune to other carbs.

summit has a sale on the reman qjets right now so im kinda kicking it around to maybe buy one.

im hopeing to hear good about reman carbs but id rather ask then to spend $280 on a headache =[ and for this matter, im not sure summit offers a qjet for my no emissions carb with a manual choke set up ( i changed a few things )

i think the qjet will fit on my performer intake but i havent looked too far into this all

i do love my eddy carb, at part throttle putting up a hill ( no load ) i get 15.5 afr and wot drops down to 10, its a tow truck so im not gonna tune wot..

also getting 8 mpg towing our 4000 lb boat and 8 mpg daily driving so it seems its rather efficient

First, if the mpg or drivability was worse than it is now I could see trying a Q-jet. But the mpg you cite isn't bad at all, IMO. That said, tuning the carb can still benefit you if the step up springs are enrichening too early, or if the rods are too rich anywhere in the fuel curve. I would still tune for WOT as well.

Also use only as much accelerator pump volume as needed- many times the pump is set to the max shot and left there w/o any testing. The shooter size can have as much to do w/it as the volume as far as tuning it goes.

You can try a 4-hole or divided spacer (keeps the plenum divided) under the carb to insulate it from heat and to add a bit of runner length.

Has the ignition system- including the advance curve and vacuum advance- been optimized? Having a good curve will help a lot in some cases, depending on how it's set up now.

What are you running as far as exhaust? Things that will often help:
• full length headers (preferred over shorty-types)
• dual exhaust pipes w/dual mufflers or at least a muffler w/dual inlets/outlets
• H or X connection between the two sides, aft of the collector/before the mufflers

Other things to consider:
• Have cooler outside air ducted to a big low restriction air filter
• Use an EGR system
• Use synthetic lubricants

[LEROYDOZOIS]

Originally Posted by oldbogie

I don't think the cost and effort to put a Q-Jet on this will be justified by the result. The Q-jet does very well where cruise can be maintained on the primaries at moderate RPMs, when you are in it deep enough to trip the power enrichment and or the secondaries the mileage goes down quickly. The Edlebrock carb is the old Carter AFB/AVS design which shares many of the high efficiency features of the Q-Jet these being the primary ratio is controlled with metering rods in the jet. So depending on how many steps or tapers are on the rod the mixture can be more tightly controlled in the cruise range. The rod also controls the power enrichment from its bottom step. This compared to the Holley which essentially has only two steps a fixed jet for main metering across a wide RPM range and a off or on diaphragm valve for power enrichment. Still when carefully set up the Holley can come might close to the efficiencies of the Q-Jet or Carter/Edlebrock.

I have a friend with a 1970, 3/4 ton, 454 powered Chevy with a TH400 that he uses to tow his boat. It had a worn out Q-Jet; he went through a bunch of reman Q-jets none of which worked properly and one blew an ocean of gasoline all over the engine room, thankfully no fire, but the kind of thing that puckers your gonads. I finally talked him into a spread bore Holley from Summit. It bolted right on, ran super fine out of the box, he wanted me to tune it, I drove the truck around town and up and down I-5 for a few miles and brought it back to him telling him I doubted there was anything I could do that would make an improvement he could feel or measure. The mileage is super close to what the original Q-Jet gave before it wore out, maybe a half mile MPG less. One can by a lot of gas at that rate against the cost of finessing this toward better. So we let it be.

Bogie

its funny you mentioned the spreadbore holly. ive heard some good about them being nice and dependable. i kinda wondered if maybe in future projects it might be worth it to purchase one and learn about them

[DoubleVision]

Spreadbore holley's work fine. However they are a pain in the assets to bolt on. especially in the rear as the float bowl is dead on top of the bolt flange.
If you want a good Quadrajet you're gonna have to pay for it. Not bashing Summit's carbs as Summit usually backs up what they sell, but Sean Murphy Induction and Jet offer Quadrajets that are very high quality carbs, but they're a bit more expensive. Even so I only run Quadrajets, I will say if you were to go with one you'd likely find the mileage would be a very marginal improvement. If you want better fuel economy look elsewhere, Tune it up with the best pieces avalible, use spiral core spark plug wires, run synthetic fluids in everything on the vehicle to cut resistance, use synthetic grease to pack the wheel bearings.

[LEROYDOZOIS]

Originally Posted by DoubleVision

Spreadbore holley's work fine. However they are a pain in the assets to bolt on. especially in the rear as the float bowl is dead on top of the bolt flange.
If you want a good Quadrajet you're gonna have to pay for it. Not bashing Summit's carbs as Summit usually backs up what they sell, but Sean Murphy Induction and Jet offer Quadrajets that are very high quality carbs, but they're a bit more expensive. Even so I only run Quadrajets, I will say if you were to go with one you'd likely find the mileage would be a very marginal improvement. If you want better fuel economy look elsewhere, Tune it up with the best pieces avalible, use spiral core spark plug wires, run synthetic fluids in everything on the vehicle to cut resistance, use synthetic grease to pack the wheel bearings.

Thanks for the input DV, i do need new spark plug wires being i have no ide how old the ones i have are, u mentioned spiral core so maybe ill check out the $$$ on them.

[eric32]

Well I will put my experience in here. My brother had a 305 in a 88 caprice clasic that had a qjet on it and we got rid of it and the computer stuff and converted it to a standard hei and put a holley 600 vacuum secondary carb on it and got almost the same fuel mileage as the qjet and the holley carb was in stock form for jets etc. So you might not gain that much difference to warrant a new carburetor buy. Like mentioned above a holley can come close if it is tuned well to the right application. Hope that helps you out with your decision. Yes a qjet will get more but not that much in my opinion and experience. Good luck.
Eric

[Hippie]

Q-Jets can get good mileage but they can't work miracles. If you're truck is working that well with the Edelbrock I really doubt you'd see enough MPG gain from the Q-Jet to justify the expense. I did pick up 2 MPG over a well tuned Holley 6619 on my old 318 Dodge PU by switching to a reman'd. Q-Jet. That was a score, found it on a "Cash for Clunkers" victim at the local boneyard. Brand spanking new, must have put it on right before they traded it in. Got it for $40! For $40 it was worth changing carbs but I wouldn't have spent full price for one on a gamble that I "might" pick up a couple MPG.

I bought a Summit Q-Jet a few years ago for a '76 Monte Carlo 350 and it worked great. I was going to use an Edelbrock 1403 500 on my current project because I already had it but I'm a Q-jet fan from way back and knew I wouldn't be happy until I had a Q-jet on it. I don't have time to build one of my cores so I ordered a reman with the correct linkage arm for my vehicle which should be here any minute now. I spent the money in this case because I "wanted" a Q-Jet and no other reason.

[oldbogie]

Originally Posted by LEROYDOZOIS

Thanks for the input DV, i do need new spark plug wires being i have no ide how old the ones i have are, u mentioned spiral core so maybe ill check out the $$$ on them.

I highly recommend Taylor either Spiro-Pro or Thunder Volt, these are reasonably priced and just keep on working <<< Taylor Cable Products - Spark Plug Wire Sets and Acessories >>>. We constantly are testing stuff and I can easily say that on high mile street driven machines and specifically on my old 350 powered S15 creeping on to 350,000 miles that these Taylors have out performed and outlasted the OEM, MSD, and Accel wires. I normally replace plug wires on a two year interval timed with the SMOG inspection every other year. The OEMs didn't make it 2 years without glowing in the dark. MSD and Accel were starting to leak around the plug boots from the header heat. The number one cylinder's spark plug boot of the Accels got against a tube and melted a small hole in the 90 degree cap where it turns. Went through a couple sets of each as I was pretty happy with them. 4 years ago I put on a set of Taylor Thunder Volt 40 ohms per foot, wasn't too sure how the computer and injection would like them, that didn't create a problem but you can listen to the ignition if the stereo is not tuned to a strong AM station, it picks up a little on FM as well but you really have to listen for it and be a long way from the station. They were in such good shape at two years I left them on. Now creeping up on 4 years I'm just starting to get an occasional miss on cold wet mornings. They also got the boot up against the number 1 header tube, nothing happened to the boot. The Sandersons really crowd the number 1 plug on these LT1 heads, it takes a lot of attention when messing around under the hood not to bump this cylinder's boot against the header tube. My wiring is all and has aiways been over the the rocker boxes, drop between the front to middle and rear to middle tubes, turn under the tubes and connect to the plugs so the wires see a lot of heat. All of them except the OEMs put up with that quite well the Taylors just have done better.

Bogie

[ap72]

Originally Posted by LEROYDOZOIS

currently atm i have a eddy 1405/1406 on my 85 454

ive been reading all over the internet that the qjets will beat mpg out of the ball park no matter what you do/tune to other carbs.

summit has a sale on the reman qjets right now so im kinda kicking it around to maybe buy one.

im hopeing to hear good about reman carbs but id rather ask then to spend $280 on a headache =[ and for this matter, im not sure summit offers a qjet for my no emissions carb with a manual choke set up ( i changed a few things )

i think the qjet will fit on my performer intake but i havent looked too far into this all

i do love my eddy carb, at part throttle putting up a hill ( no load ) i get 15.5 afr and wot drops down to 10, its a tow truck so im not gonna tune wot..

also getting 8 mpg towing our 4000 lb boat and 8 mpg daily driving so it seems its rather efficient

The edelbrock carb is one of the best street carbs you can find, I'd take one over a Q-jet every time. That being said tuning your carb a little finer can help pick up a mile- MAYBE 2- a gallon. Try a leaner secondary step, and move your pump arm lever out to the last hole.

[cobalt327]

Darn, wish I'd have thought of tuning the Edelbrock...

OP, any chance you missed this post (you were posting the same time I was): summit reman q-jets? If you did miss it, can you fill in any more info? If you saw it and decided not to respond, then that's OK too.

[LEROYDOZOIS]

Originally Posted by cobalt327

Darn, wish I'd have thought of tuning the Edelbrock...

OP, any chance you missed this post (you were posting the same time I was): summit reman q-jets? If you did miss it, can you fill in any more info? If you saw it and decided not to respond, then that's OK too.

are you talking to me or someone else ??!!

[cobalt327]

Someone else.

[Studebaker]

Nothing wrong with the rebuilt Summit Quadrajets. They do a good job as a stock replacement carb. I also read that someone mentioning "JET" brand carburators. Speaking from personal experience in dealing with this company, don't just walk away, Run as fast as you can. I ordered a quadrajet from "Jet"for a restoration for a stock 390 HP 427 chevy project. The "Jet" carb came missing the secondary metering rods and they stated that the carb had been flowed on their flow bench, yea right. Then they stuck me with shipping both ways to repair a carb that was improperly rebuilt in the first place. I don't know what metering rods they then stuck in there, The returned carb never worked right, they wouldn't return any phone calls, no customer care or service. But it was expensive. "Jet" Is not a company you want to do business with!