I was reading through some earlier posts on this list, and noticed
that increasing the plug gaps could lead to an increase in MPG. With
the price of gas, I'm wondering if this would work on my truck?
Here's how it's currently set up: 86 GMC 1500; 5.7L V8; R44TS @ .045
gap; HEI; Delco cap, wires, & coil, NAPA roter; Rochester Q-jet.

The truck runs fine, so I don't want to mess with the ignition system
too much, but for better MPG I'm willing to give it a try if there's
no real down side. Anyone tried this? What plugs? What gap? What,
if any modifications? What downside?

Thanks in advance for any replies.

"86GMC" <gunnloud (AT) gmail (DOT) com> wrote

If the truck runs fine with no missing or stumbling you are probably already
getting close to optimum fuel mileage.


--
Insanity is Hereditary - you get it from your kids

On 15 May 2007 14:51:40 -0700, 86GMC <gunnloud (AT) gmail (DOT) com> wrote:
I was reading through some earlier posts on this list, and noticed that
increasing the plug gaps could lead to an increase in MPG. With the
price of gas, I'm wondering if this would work on my truck? Here's how
it's currently set up: 86 GMC 1500; 5.7L V8; R44TS @ .045 gap; HEI;
Delco cap, wires, & coil, NAPA roter; Rochester Q-jet.
The truck runs fine, so I don't want to mess with the ignition system
too much, but for better MPG I'm willing to give it a try if there's no
real down side. Anyone tried this? What plugs? What gap? What, if any
modifications? What downside?
Thanks in advance for any replies.


XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX


Group: alt.trucks.chevy Date: Tue, May 15, 2007, 10:07pm (EDT-3) From:
demi (AT) moore (DOT) net (Ashton*Crusher)
Here's my theory. If it were really that simple they would do it at the
factory. Most likely this story got started by someone who took their
old gunky plugs out and put in a new set of plugs, and oh by the way,
gapped the new ones wider, and concluded that it was the wider gap that
made the mileage go up.

ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ


I've Been doing this for years and it works. First time I ever heard
about it was when I read about it in a Chevy performance magazine.
Gapping .010 inch to .015 inch over stock will give you a slight
improvement in fuel mileage but If you go beyond that, you could
experience hard starting and even misfires at speed. You must make sure
that the entire ignition system is in good working order and you need to
check the gap on a regular basis (I check mine in the fall and spring).
Low resistance ignition wires are a help also as is a high output coil
(both give a stronger spark).


The Q-jet can be made to give you respectable gas mileage by being very
meticulous about setting it up. I paid a mechanic to do mine and ended
up doing it a few weeks later because the guy screwed it up. Helms used
to have a great field repair manual for the Q-jet but I don't know if
the still offer it. If you really want good fuel mieage, just do the
basics like front end alignment, tire pressure, driving techniques, etc.





/?/?/?/?/?/?/?/?/?/?@@@@@@@@@@?/?/?/?/?/?/?/?/
You should never confuse the issue by injecting the truth. ~ unknown ~

Plug gap will have nothing to do with mileage. The only reason the gaps
were widened over the years was to fire the leaner mixtures. If you're not
experiencing misfire, then you'll not increase mileage.

--
Steve Barker




"86GMC" <gunnloud (AT) gmail (DOT) com> wrote

Any of these Magical fixes, if they really worked the Auto Manufactures
would be doing it as it's in their best Interest.


"Steve Barker" <ichasetrains (AT) some (DOT) yahoo.com> wrote

"PerfectReign" <theperfectreign (AT) yahoo (DOT) com> wrote

Well be smart about it and do it on top of a large hill so you'll still be
able to go someplace and not have to push.

Sounds like I'll just stick with the set-up I've got. The slightly
wider gap = fatter spark = more complete combustion logic makes sense
though. Anyway, thanks to all for posting their experience.

86GMC <gunnloud (AT) gmail (DOT) com> wrote in news:1179265900.762905.9730
@o5g2000hsb.googlegroups.com:

the us house of repesentatives paseed a bill (hb p.o.everybody 123) that
makes it a felony for auto manufacturors to increase spark plug gap above
prescribed numbers. the bill listed vp cheneys profit margin and prez
bush.s lack of giving 2 shits as the reason.....please refrain from
increasing gap as it could piss of our elected officials and they might
take aggresive action in places that have nothing to do with much at
all!..............serious note: the catalyst causing the explosion in the
cylinder could be caused by a pygmy with a cigar lighter, a normal spark
plug or just excessive heat (preignition). you still get the same power
out of the power stroke.......the timing of the spark is where you see
remarkable power and mileage diffs........with the advent of computer
controlled spark timing the general public has lost their input into
changing ign. timing...their are chips and gizmos all over that promise
everything from a zillion miles per tank to brittany spears giving you a
lap dance. believe what you want but i think the manuf. has givin you the
best POSSIBLE settings to squeeze out the best POSSIBLE MPG.........YOU
CAN ALWAYS BACK THIS ETHENOL FAD AND THEN PAY 20 BUCKS FOR AN EAR OF CORN
OR OF COURSE THEIR IS THE WATER INJECTION SYSTEMS THAT WERE ALL THE RAGE
IN THE 70's..........................kjun
--
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