was curious what was more fuel efficient.. using a single or dual carb setup? (regardless of engine size)
any help, info, stories greatly appreciated.
vassy66T1 ·
I have had both a single (42dcn) and duals (36idf's) on my 1776cc with a mild cam and just the usual balancing of internals and getting compression ratios right.
The motor is in my Kombi, and on a long trip with the duals I got 28mpg. That was sitting on 95-100km/h.
Round town it does quite well also.
The single wasn't any better, and may have even been a bit thirstier. Powr comes on a lot more smoothly across the rev range with the duals so you don't have to work the motor as hard i found.
I think it's a matter of getting the jetting spot on.
Doug Sweetman ·
Jetted correctly, a set of duals will give better economy. Doesnt sound logical until you realise with a single you have such long intake manifold runners that fuel can actually condense on the runners, thus requiring a richer ratio (more fuel) to make up for the amount that condenses.
often by increasing an engine's output you can reduce fuel consumption. sound whacky? sure, but when you realise you dont have to hammer a larger or tweaked engine as much as a small or stock one to get the same driveability, it obviously uses less fuel. (to a point of course :P)
I had a toyota crown once with a 2.8L six in it, which would get at best 350 to 400k's from 60L on the f3 freeway which I drive reguarly. it wighed 1550kg and had high gearing to suit.
I fitted a 3.0L Supra turbo motor into it and instantly could get 600k's from 60L of fuel onm the freeway!
of course if I gave it heaps it'd go through that 60L in 200k's :o😀