I look and looked and looked. Can't find this question so here goes. Which 4 barrel carb gets the best mpg for a 440 auto mopar? Someone said carter avs, then someone else told me, no just get the holley rebuilt talored to mpg, then another guy said no edlebrock, then another guy said no carter thermoquads are best...After doing research, I believe carter thermoquads get the best mileage and very good acceleration too due to tiny primaries and huge secondaries, but those goofballs at carter built it using a plastic body so they tend to warp, darn, nothing is easy.
I have a rebuilt holley 4160 for about 6 years. Its leaking inside the carb somewhere. It stinks of gas at cruising speed. The best mpg I got was after rebuild 12 / 16 mpg, but now its 10 /14. I'd like to get at least 13/17 as some people stated here are getting.
Anyone know how long it takes the carter TQ to warp? or other problems? is it the best for mpg?
Joined: Tue Oct 11 2005, 01:33AM
Location: Calgary, Alberta
Posts: 5893
I wonder if this question can be answered without taking into account driving habits, engine condition and the ability of the owner to get the tuning correct. Different strokes for different folks applies to carbs and cars I suspect.
If you must rely on someone else to setup and tune your carb, then you'd best buy the type of carb he knows the best. If you will do it yourself, then you need to pick one and become a tuning expert.
I think most guys armed with a set of instructions should be able to get good mileage. To go the next level and achieve outstanding mileage requires a master's touch. !thumb
Perhaps the question should be, "Which carb is the easiest to learn and setup ?" or possibly "Which carbs tend to retain their settings and which tend to wander as conditions change?"
In the end, the ultimate solution is computer controlled fuel injection! !study
I'd use an Edelbrock AVS (basically an updated copy of the the Carter AVS). Easy to tune to your engine, and once set, it stays that way.
Many guys on the dock love the Thermoquad, and the warping plastic body problem is a myth. They do have some issues with internal washers going bad, but apparently they are pretty easy to repair.
Joined: Fri Mar 13 2009, 11:21AM
Location: San Marcos, CA
Posts: 713
By design, the Carter Thermoquad should give you the best mileage. They are a great carb but they take a lot of tinkering to get them just right. My $02
Joined: Tue Oct 11 2005, 01:33AM
Location: Calgary, Alberta
Posts: 5893
I'm liking the replies! !thumb !thumb
First I fall into the group who must rely on others to tune my car, carbs and automatic transmissions are personal black holes!
My 440 was born with a Holly which IMO was a piece of crap. I dumped it and replaced it with a Carter AVS. The AVS worked better that the Holly, but it seemed to need a lot of baby sitting to retain its settings. One of the Cbody guys here in Calgary was admiring it, so I gave it to him.
I've now bought an Edelbrock 750 cfm and have decided to sit down and really learn how to set it up and how to really get the tuning right.
Joined: Sat Apr 25 2009, 03:08AM
Location: Out West
Posts: 626
I replaced the POS Holley stocker with a NOS AVS I found a few years ago and it has been great. I never had to even touch it since except to take it out of the box, bolt it on and connect the lines and throttle cable. I moved the idle air screws maybe a quarter turn after it was warmed up the first time and that was it - literally.
Joined: Thu Aug 19 2010, 12:27PM
Location: Finland
Posts: 35
Fury440 wrote ...
I've now bought an Edelbrock 750 cfm and have decided to sit down and really learn how to set it up and how to really get the tuning right.
Best way to get it tuned yourself is to get a wideband lambda with gauge. All you need to do is just weld a bung in your exhaust pipe, do some simple wiring for the gauge and start to adjust.
Do some cruising around and look what is your Air/Fuel ratio. then adjust leaner or richer according to edelbrock calibration chart. there is simple charts that tell you what needles and jets you should use.
Personally i like to calibrate my carburators so that it is little lean at cruise(A/F ratio about 16) and at powermode little rich.(i region of A/F ratio 12). At idle ratio is about 14.5-15 A/F ratio.
You will learn fast how to tune that carb. But when you got it deacently close to what you want, turn of that gauge. You will lose your sleep over it, if you dont know when to stop. There is so many variables(like weather for example) that it will never be perfect.
Joined: Thu May 01 2008, 11:15AM
Location: Chicago,IL
Posts: 2868
4160 is a similar idea to a TQ or quadrajet, just not as complicated. Might be as simple as a bad power valve in your current carb. I'd give that a try first.