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I still want to know how you pull these types of MPG. Especially with your “up-armored” tub...with a Q-jet on my 283 I returned around 13mph average. On the super mild (stock) 350 I replaced the 283 with I get about 10mpg. I’ve been goin back and forth about messing with the jets and rods to see if I can do better but 18mpg seems very likely unattainable.
I still want to know how you pull these types of MPG. Especially with your “up-armored” tub...with a Q-jet on my 283 I returned around 13mph average. On the super mild (stock) 350 I replaced the 283 with I get about 10mpg. I’ve been goin back and forth about messing with the jets and rods to see if I can do better but 18mpg seems very likely unattainable.
I’ve not calculated economy with the new motor and setup.
With that setup I’d average around 13mpg. It had 10.25:1, a Wolverine Blue Racer RV cam, a well worn Q-jet, point distributor with heavy weights & light springs, Accell adjustable vacuum advance, and regular pump gas.
I messed with the distributor a lot... at factory timing, it’d ping on regular gas. With a lot of trial and error, I retarded the timing to almost eliminate ping, and then adjusted the vacuum advance to have the most advance I could get away with without ping. Throw in a lot of adjustment, test drive, adjustment, test drive, ferry dust, Ajustments, and test drive... till I was happy with the results.
My best run wasn’t by any means an average tank. Most driving I do here would all classify as city driving... going 5-10 minutes on the highway now and then doesn’t really let you determine what a truck can do. The truck was warm and I wanted to see what it was capable of getting. I filled both tanks, got back out on the highway, switched to the Auxiliary tank, nursed it at 50 mph +/- on fairly level ground (Annacortes to Vancouver, BC) till I had to slow down for the border crossing, and then switched back to the main tank. It was a 100 mile run that used 5 gallons.
1970 FJ40, 350 ci, 2bbl, stock 3 speed, 4:11's and 31inch tires. Open road no load holding at 2500 rpm's with cruise control I have managed as high 15mpg.
Pulling a 16 foot travel trailer, can't remember weight, on open road usually with cruise control holding at 2500 rpm's 10-13 mpg,
The LC and I have been retired for a while now so mostly stop and go driving in a tourist town with a lot of hills so I don't even try to keep track of mileage.
Also I like to romp it every once in a while to rattle the glass-packs to compete with the Harley's.
Does anyone know if the torx screws for the timing plate are available anywhere?
hOOter
My 350 with mild rv cam and quadrajet once measured out at 15 mpg. I never remeasured it again... my math may be suspect, but I’m sticking to that number.Did a little better today - 130 mile round trip burned about 10.7gal of gas or just around 12mph - better than the 10 I pulled going to Lancaster this winter. This trip was more windy, slow back roads - not much above 50mph aside from a brief stint down route 30 at 65 (and a very brief stint at 80mph to prove to my buddy the truck could do it).
Long story short - seems like the "magic rpm" is about 2300 (or 50-55mph). Anything in excess of that and the fuel economy starts plummeting fast. I still think I could tweak the tune on the carb and lean it out a little but I'm having too much fun driving it to get back to fixing it!
Installed a new 12v port in the back of the heater. Then discovered a new visitor in the back yard.
What’s that button? There is only blanco cover in my BJ42, although it looks just similar.
Nice JeepCut out the wheel wells and installed some TJ fender flares after moving the axle back from a spring reversal.
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After a bit of cutting and sanding, looks like they were made for the FJ.