Vanning.com logo
Boxdin
Site Navigation


Advertisements
Recent Posts
Any good threads with some pics showing molded in fender flares????
by Astrocreep66. January 17th 2019 7:13 pm
Dr. Bob's Jokes Thread
by Astrocreep66. January 17th 2019 7:07 pm
new guy intro
by Astrocreep66. January 17th 2019 7:03 pm
Sold for $59,000
by amx. January 17th 2019 6:00 pm
WTB: Driver's Seat Base For 1985 Chevy G Van
by tuner4life. January 17th 2019 4:40 pm
new here, thinking of getting a van
by Wizard78. January 17th 2019 4:14 pm
1978-1982 chevy van parting out
by jcd74. January 17th 2019 12:49 pm
NOS GM Lower body aluminum moldings for 71-80 chevy van
by black79gmc. January 17th 2019 9:51 am
Robo's Lowrider Boogie Van
by RoboforcerX2000. January 16th 2019 10:46 pm
Snowball 43 - Hosted by Moon Lite Vans
by ForPlay. January 16th 2019 7:52 pm
Featured Links
Vanning.Com is a an authorized Amsoil Dealer


Previous Thread
Next Thread
Print Thread
Rate Thread
350 5.7 fuel mileage #733946
March 12th 2018 3:47 pm
March 12th 2018 3:47 pm
Joined: Feb 2018
Posts: 57
Ohio
J
jgarrett Offline OP
journeyman
jgarrett  Offline OP
journeyman
J
Joined: Feb 2018
Posts: 57
Ohio
i have a 350 with a stock quad jet carb on it. I think im only getting around 10mpg. Would i be able to get any better gas mileage with a new quad carb?

AdSense long
Re: 350 5.7 fuel mileage [Re: jgarrett] #733947
March 12th 2018 3:57 pm
March 12th 2018 3:57 pm
Joined: Nov 2013
Posts: 3,020
Michigan
Dyno_Dave Offline
pooh-bah
Dyno_Dave  Offline
pooh-bah
Joined: Nov 2013
Posts: 3,020
Michigan
If the current carb is the problem, perhaps. And I DO NOT mean that to sound like a smart ass answer. A properly tuned Rochester Quadrajet can deliver good mileage. The small primaries for cruising make it an efficient carb under light throttle / load.

But there are LOTS of variables for fuel mileage. State of tune (plugs, wires, PCV, no vac. leaks), weight of vehicle, aero (extra wind dragging spoilers or raised roof?), driving style (do yo udrive conservatively, or a little more aggressively?), driving conditions (cold weather with lots of choke operation, lots of hills?), gear ratio, OD trans? Is the choke opening as fast as it should (or is the heated crossover that powers the choke clogged...or is it electric and inop)? Timing (set to spec, or retarded to allow low grade fuel, further retarded to avoid spark knock from carboned up combustion chambers from leaking stem seals, or inop. EGR)? Vacuum advance working? Lots of things go into it.

But a worn out carb, with floats that are 1/2 sunk leaving it running rich? Sure, that will hurt MPG, and a rebuild would fix that.


Re: 350 5.7 fuel mileage [Re: Dyno_Dave] #733949
March 12th 2018 5:33 pm
March 12th 2018 5:33 pm
Joined: Feb 2018
Posts: 57
Ohio
J
jgarrett Offline OP
journeyman
jgarrett  Offline OP
journeyman
J
Joined: Feb 2018
Posts: 57
Ohio
awesome man definitely alot to think about. I think ill start with replacing some of the vacuum lines and changing the egr valve right away.

Re: 350 5.7 fuel mileage [Re: jgarrett] #733950
March 12th 2018 6:46 pm
March 12th 2018 6:46 pm
Joined: Mar 2016
Posts: 323
Tucson,Az.
H
Hasan Ben Sobar Offline
enthusiast
Hasan Ben Sobar  Offline
enthusiast
H
Joined: Mar 2016
Posts: 323
Tucson,Az.
What Dave said. You timing curve is in need of attention as well. Talk to someone who knows how to tune a SBC. The Q-jet is NOT the weak link in the chain if all other things are equal..


Tucson-it's a dry heat...like an oven

Moderated by  Astro, nautic1 

Donate


Upcoming Events
discovery
Who's Online Now
0 registered members (), 0 guests, and 5 spiders.
Key: Admin, Global Mod, Mod
Newest Members
Noah, Delbert359, Sportsmobileguy, textual, lynchmob2000
10716 Registered Users
Top Posters(30 Days)
frscke1 36
Forum Statistics
Forums68
Topics35,198
Posts516,254
Members10,717
Most Online177
May 8th, 2013

Powered by UBB.threads™ PHP Forum Software 7.6.1.1