Im kinda changing the subject but this thread is almost dead anyway so I
guess nobody will mind that much.

I never did quite understand how worn plugs and stuff hurt fuel economy
unless a cylinder is dead. I dont understand how it controls how much fuel
goes into the engine. If you always press the accelerator to the floor when
you accelerate, you send the same amount of fuel to the cylinders
regardless if it burns or not.

But if my ride starts missing then I have to do somthing about it. If the
plugs are fauled then I will clean them. If they are worn then I will
replace them. But only if it starts missing.

Also after I replaced the plugs, dis cap and wires. I could not tell any
difference in gas mileage. But I did replace them the same week it started
missing. Come to find out it was the wires causing it to miss even though
the plugs were shot.


> >
> > Even if you are poor...one sparkplug will be around USD 1,50 I recon or
> > am I wrong here?
> > Erik-Jan.
> plus what you have lost in fuel economy would have paid for new plugs long
> ago.
> you are going to stay poor longer at this rate
> Ron
>
>

There are misses and then there are misses. An ignition system can be
degraded a lot without producing a perceptable 'miss'. Less than
optimum spark -> less than optimum burn -> less power. Eureka! Give
it more gas to do the job.

If you always press the accelerator to the floor when you accelerate,
why are you asking about gas mileage? The biggest gas hog known is a
heavy right foot.

On Mon, 21 Feb 2005 05:21:42 UTC "John Doe Jr" <noaddress@aol.com>
wrote:

> Im kinda changing the subject but this thread is almost dead anyway so I
> guess nobody will mind that much.
>
> I never did quite understand how worn plugs and stuff hurt fuel economy
> unless a cylinder is dead. I dont understand how it controls how much fuel
> goes into the engine. If you always press the accelerator to the floor when
> you accelerate, you send the same amount of fuel to the cylinders
> regardless if it burns or not.
>
> But if my ride starts missing then I have to do somthing about it. If the
> plugs are fauled then I will clean them. If they are worn then I will
> replace them. But only if it starts missing.
>
> Also after I replaced the plugs, dis cap and wires. I could not tell any
> difference in gas mileage. But I did replace them the same week it started
> missing. Come to find out it was the wires causing it to miss even though
> the plugs were shot.
>
>
> > >
> > > Even if you are poor...one sparkplug will be around USD 1,50 I recon or
> > > am I wrong here?
> > > Erik-Jan.
> > plus what you have lost in fuel economy would have paid for new plugs long
> > ago.
> > you are going to stay poor longer at this rate
> > Ron
> >
> >
>
>


--
Will Honea

If a plug doesn't fire well, it is possible that on some revolutions
of the engine the cylinder won't fire, or fires poorly. Not enough for
you to feel, but enough to affect fuel mileage (actually performance,
the fuel mileage hit is your fault as you try to make up for the
performance hit! <g>)

On Mon, 21 Feb 2005 00:21:42 -0500, "John Doe Jr" <noaddress@aol.com>
wrote:

>I never did quite understand how worn plugs and stuff hurt fuel economy
>unless a cylinder is dead. I dont understand how it controls how much fuel
>goes into the engine. If you always press the accelerator to the floor when

I always thought as long as the fuel mix lights then its all going to burn
assuming the mix is right. Little flame becomes a big flame. Also the flame
will still start in the same place every time reguardless as to how hot the
spark is. But I do agree if the spark is too weak then it will not light the
fuel every time. Now if you could send a spark from the plug to the piston
then you could light more of it all at the same time to get more power.
Hoping it does not burn a hole in the piston.

But then I here some people say slower burning fuel gives more power and
others say faster burning fuel gives more power. Im not really sure who is
right on that one. But im leaning towards faster burning. But thats too far
off topic.

As to the question "If you always press the accelerator to the floor when
you accelerate,
why are you asking about gas mileage?" that was just a reply to the comment
that was made "plus what you have lost in fuel economy would have paid for
new plugs long ago." was to just try to get my point across. I really do not
think it makes a noticeable difference. At least I could not see any when I
gave my f-150 a complete badly needed tune up.

I do try to keep an open mind. So if you can explain to me why im wrong then
I'm willing to change my thinking. I am just asking for a good explanation
before I change. The ones below are pretty good though. I just dont
understand less than optimum burn from a weak spark across a small gap.


"Will Honea" <whonea@yahoo.com> wrote in message
news:JxX2tWiP5BNp-pn2-qQVY9ESDFJs9@anon.none.net...
> There are misses and then there are misses. An ignition system can be
> degraded a lot without producing a perceptable 'miss'. Less than
> optimum spark -> less than optimum burn -> less power. Eureka! Give
> it more gas to do the job.
>
> If you always press the accelerator to the floor when you accelerate,
> why are you asking about gas mileage? The biggest gas hog known is a
> heavy right foot.
>
>

If a plug doesn't fire well, it is possible that on some revolutions
of the engine the cylinder won't fire, or fires poorly. Not enough for
you to feel, but enough to affect fuel mileage (actually performance,
the fuel mileage hit is your fault as you try to make up for the
performance hit! <g>)

On Mon, 21 Feb 2005 05:21:42 UTC "John Doe Jr" <noaddress@aol.com>
> wrote:
>
> > Im kinda changing the subject but this thread is almost dead anyway so I
> > guess nobody will mind that much.
> >
> > I never did quite understand how worn plugs and stuff hurt fuel economy
> > unless a cylinder is dead. I dont understand how it controls how much
fuel
> > goes into the engine. If you always press the accelerator to the floor
when
> > you accelerate, you send the same amount of fuel to the cylinders
> > regardless if it burns or not.
> >
> > But if my ride starts missing then I have to do somthing about it. If
the
> > plugs are fauled then I will clean them. If they are worn then I will
> > replace them. But only if it starts missing.
> >
> > Also after I replaced the plugs, dis cap and wires. I could not tell
any
> > difference in gas mileage. But I did replace them the same week it
started
> > missing. Come to find out it was the wires causing it to miss even
though
> > the plugs were shot.
> >
> >
> > > >
> > > > Even if you are poor...one sparkplug will be around USD 1,50 I recon
or
> > > > am I wrong here?
> > > > Erik-Jan.
> > > plus what you have lost in fuel economy would have paid for new plugs
long
> > > ago.
> > > you are going to stay poor longer at this rate
> > > Ron
> > >
> > >
> >
> >
>
>
> --
> Will Honea

The physics of how that fuel burns is complex. It is not instant (when
it is, you get a knock!) but takes a measurable amount of time. The
beginning of the burn, that is when the spark first ignites the
fuel/air mixture, is the slowest part. The hotter (bigger, more
powerful, etc.) the spark, the more mix is ignited, which gives it a
head start on the combution process.

This becomes more critical as engine speed increases (there is less
time for complete combustion) so an engine can have a high speed miss,
and run well at lower speeds. The opposite can be true, but for a
different reason, the spark is 'hotter' at lower revolutions
generally, but sometimes there is a point where as engine speed drops
it cannot ignite the mix.

Another factor is that as a plug 'wears' and the gap becommes larger,
the ignition timing changes! It takes more voltage to bridge that gap,
and that takes longer to create. This type of problem can happen with
new plugs that are gapped incorrectly, or with worn plugs.

One could write a book about this... Oh, wait a minute, I bet someone
has! <bg>

On Tue, 22 Feb 2005 14:08:01 -0500, "John Doe Jr" <noaddress@aol.com>
wrote:

>
>I do try to keep an open mind. So if you can explain to me why im wrong then
>I'm willing to change my thinking. I am just asking for a good explanation
>before I change. The ones below are pretty good though. I just dont
>understand less than optimum burn from a weak spark across a small gap.
>

Thanks for the info. That was enough to set me strait. Plus that explains
why I never seen any difference in my F-150. I very rarely run it over 3000
RPMs

"Peter D. Hipson" <phipson@deletethisword.darkstar.mv.com> wrote in message
news1cn115d3im6v35fsrt15a9rgfaaj07sjo@4ax.com...
> The physics of how that fuel burns is complex. It is not instant (when
> it is, you get a knock!) but takes a measurable amount of time. The
> beginning of the burn, that is when the spark first ignites the
> fuel/air mixture, is the slowest part. The hotter (bigger, more
> powerful, etc.) the spark, the more mix is ignited, which gives it a
> head start on the combution process.
>
> This becomes more critical as engine speed increases (there is less
> time for complete combustion) so an engine can have a high speed miss,
> and run well at lower speeds.

With that truck, you can only do it once... <g> (I had one of those
300 ci straight six engines in an f-150 once. Never needed to go over
3000 RPM!

On Wed, 23 Feb 2005 01:41:08 -0500, "John Doe Jr" <noaddress@aol.com>
wrote:

> I very rarely run it over 3000
>RPMs
>

I kinda wish I had a six. Mine is a 302 V8. It still sucks gas even with a
with a new tune up. Luckly I only put around 1K or less a year on it now.
Only drive it when the weather is really nasty or I need to haul somthing or
simply to run the old gas out so I can put in fresh now and then. Ride the
bike during dry summer days and the Mazda Tribute for the rest. The only
reason I keep it is because its paid for and its proven to be very reliable.


"Peter D. Hipson" <phipson@deletethisword.darkstar.mv.com> wrote in message
news24p11dlr3h32ntgu6g9h86d7dhvtpcamh@4ax.com...
> With that truck, you can only do it once... <g> (I had one of those
> 300 ci straight six engines in an f-150 once. Never needed to go over
> 3000 RPM!
>
> On Wed, 23 Feb 2005 01:41:08 -0500, "John Doe Jr" <noaddress@aol.com>
> wrote:
>
> > I very rarely run it over 3000
> >RPMs
> >
>

1.98 each here...so 11.88,no big deal for me.(and im a cheap basterd)




"Scotty" <noricer@comeagain.com> wrote in message
news:4182c44e$0$32593$afc38c87@news.optusnet.com.au...
> I dont know how much spark plugs are in the US (Stuff all Id imagine) but
> here in Australia they cost around the $2-$8 mark depending on quality of
> the plugs. Why not just replace them, even on a V8 the much about factor
> would far outweigh the cost of the new plugs, even at $5 each what $40 of
an
> instant fix over hours of stuffing around with cleaning them?
>
> If you cant afford new plugs then you shouldnt be driving a car on the
road,
> who knows what else your skimping on? Tyres? Suspention parts? Safety
> issues?