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Link to advancing the stock timing?
Topic Started: Jan 18 2010, 07:34 PM (2,760 Views)
starscream5000
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Got 70 MPG?

If you destroyed/stopped up your catalytic converter by advancing your timing out to 27 BTDC, you would think that the motor is producing a more "dirty" combustion. Thinking along these lines, having the "dirtier" combustion SHOULD cause the motor to develope carbon deposits quicker, thus INCREASING the risk of burning an exhaust valve, no?

But here's the thing, where is point in the tune of a motor where an optimum, or "clean" burn is achieved, and at what timing setting does the combustion byproduct become more "dirty"??
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Woodie
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mwebb
Jan 20 2010, 06:09 PM

=======================================
for those posters who claim advancing base ignition timing absolutely will improve something

show me the test results
show me what you did and the improvement that you measured
That's like me asking you to provide careful test results supporting the claim that 14.7/1 is the best air/fuel mixture. There's no need for that as it's a basic fact universally accepted for 100 years. This is the entire point of computer controlled ignition timing maps and knock sensors. This is the entire reason for high test fuel, it allows for more ignition timing, which provides more power.
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mwebb
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FOG

starscream5000
Jan 21 2010, 12:05 AM
If you destroyed/stopped up your catalytic converter by advancing your timing out to 27 BTDC, you would think that the motor is producing a more "dirty" combustion. Thinking along these lines, having the "dirtier" combustion SHOULD cause the motor to develope carbon deposits quicker, thus INCREASING the risk of burning an exhaust valve, no?

But here's the thing, where is point in the tune of a motor where an optimum, or "clean" burn is achieved, and at what timing setting does the combustion byproduct become more "dirty"??
answer ;

when over advanced timing begins to cause incomplete combustion
OR
when over advanced timing reduces combustion efficiency

both are correct
to see when and where it happens
you would
need to measure when HC and CO start to increase using a 5 gas

or
watch for the calculated load value to change , increase , under the same conditions
do you have a "scangauge II" ? or a laptop with a scan tool in it or a MPGuino

anyone of them will show when efficiency goes down
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starscream5000
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Got 70 MPG?

The Scangauge is out of the question as mine's a '95, but I may end up getting a MPGuino some day.
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mwebb
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FOG

..."That's like me asking you to provide careful test results supporting the claim that 14.7/1 is the best air/fuel mixture. There's no need for that as it's a basic fact universally accepted for 100 years. This is the entire point of computer controlled ignition timing maps and knock sensors.

This is the entire reason for high test fuel, it allows for more ignition timing, which provides more power. "...


that is not true , the use of "high" test allows higher compression ratios with out combustion being caused by the heat of compression ,
before the combustion can be started by spark in a controlled fashion .
and
high test fuel is a poorer fuel than 87 octane fuel ,it should be called
"low test fuel " and instead of premium fuel "mediocre fuel"

in my world ,
it is common knowledge that using "high test fuel" in a system designed for 87 octane will increase carbon deposits and will result in reduced fuel economy

but let us remain focused please o please

you are attempting to introduce a new and very irrelevant variable .

my statement is that
on a stock engine (with 3tech economy cam and +10 cam wheel )
with stock compression ratio , my testing shows that using high test fuel and advancing base ignition timing more than 8 degrees btdc reduces
fuel economy on my "special" car.

do you have any kind of test results that agree with or dispute that ?
Edited by mwebb, Jan 21 2010, 11:39 PM.
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Woodie
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mwebb
Jan 21 2010, 11:34 PM

my statement is that
on a stock engine (with 3tech economy cam and +10 cam wheel )
with stock compression ratio , my testing shows that using high test fuel and advancing base ignition timing more than 8 degrees btdc reduces
fuel economy on my "special" car.

do you have any kind of test results that agree with or dispute that ? [/color]
AGAIN? I have to explain my lifetime of experience with hundreds of vehicles, six of them being Metros again? I can't just cut and paste from the last time we had this conversation?

Go find an old school mechanic, one that understands engines, from before computers told you which screw to turn. Show him a three cylinder Metro in perfect condition and ask him how he thinks the car is running without driving it or opening the hood. He will stick his finger in the exhaust pipe, look at the soot that comes out, and proclaim "that somebish is running rich as hell or needs more timing advance!"
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mwebb
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FOG

....."Go find an old school mechanic,
one that understands engines, from before computers told you which screw to turn. Show him a three cylinder Metro in perfect condition and ask him how he thinks the car is running without driving it or opening the hood. He will stick his finger in the exhaust pipe, look at the soot that comes out, and proclaim "that somebish is running rich as hell or needs more timing advance!" ".....


i do not need to find these guys -
they come looking for me
when they reach the limits of their understanding of theory and how to implement it .

then i fix the car that they could not fix
using my toys and my understanding of how things really work and a little guidance from above .
===========================================

not to be arrogant or anything
but this happens at least 2x every week
Edited by mwebb, Jan 22 2010, 11:29 AM.
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Woodie
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Okay then, that tells me there's no point in going on. The sum total of all mankind's experience with the gasoline fueled Otto Cycle engine can't stand up to your one experiment with one Metro with known problems.

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mwebb
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FOG

Woodie
Jan 23 2010, 05:51 AM
Okay then, that tells me there's no point in going on. The sum total of all mankind's experience with the gasoline fueled Otto Cycle engine can't stand up to your one experiment with one Metro with known problems.

...."The sum total of all mankind's experience with the gasoline fueled Otto Cycle engine"........
A; is constantly being UPdated and and improved upon
a- and those who will not or can not keep up are going the way of the do-do and Dinasaur

B; does not reside betwixt the ears of a do-do or a dinosaur
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billy508
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billy508

i do not need to find these guys -
they come looking for me
when they reach the limits of their understanding of theory and how to implement it .

then i fix the car that they could not fix
using my toys and my understanding of how things really work and a little guidance from above .
===========================================

not to be arrogant or anything
but this happens at least 2x every week

You Noted that this might sound arrogant, as per your disclaimer
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mwebb
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FOG

if you work on broken cars for a living
and are seeking ways to remain current with new systems

i have been a member of iatnhttp://www.iatn.net/
since 1997 and sponsoring member almost as long , there is wealth of information to be had there and i invite those that have an interest to become a member and explore the site .
it is free to become a basic member but there is a small fee if you wish to have the ability to view the archives ...
something i strongly suggest, well worth the cost .

i have been a member of TST since it was STS , another great source of learning
http://www.tstseminars.org/
even if there are no chapters in your location , the monthly seminars are available on the internet
a subscription site , but again , well worth the cost imho

anyone else have any links to sites such as these ?
no one was born knowing how to roller skate ....
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billy508
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billy508

I enjoy this site http://cr4.globalspec.com/ :banana :banana :banana
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