Hi Octane Autogas

In article . net,
UltraJohn wrote:

I double checked and it was Exxon and it is quite pricey. . .
regular 93 octane here is about 195 and this 110 leaded was 4.25 a gallon!
but hey if your running 12.5 to 13.0 to 1 compression you have to pay the
price. .;-)
John


Actually, you can get an extra boost if you mix 1:4 ratio 100LL and
premium unleaded. Low concentrations of TEL yield large octane boosting.

Orval Fairbairn wrote:

In article . net,
UltraJohn wrote:



I double checked and it was Exxon and it is quite pricey. . .
regular 93 octane here is about 195 and this 110 leaded was 4.25 a gallon!
but hey if your running 12.5 to 13.0 to 1 compression you have to pay the
price. .;-)
John




Actually, you can get an extra boost if you mix 1:4 ratio 100LL and
premium unleaded. Low concentrations of TEL yield large octane boosting.


Orval,
When you say "extra boost", what do you mean? If you mean power, you are
wrong. Higher octane is less explosive, harder to set off, less power,
that is the reason you don't get preignition. It won't ignite from high
compression, a glowing piece of carbon or early timing, etc as lower
octane will. To get the most power use the lowest octane you can with
out ignition knock.
L.D.

On Tue, 13 Apr 2004 15:47:18 -0500, "L.D."
wrote:

Orval Fairbairn wrote:

In article . net,
UltraJohn wrote:



I double checked and it was Exxon and it is quite pricey. . .
regular 93 octane here is about 195 and this 110 leaded was 4.25 a gallon!
but hey if your running 12.5 to 13.0 to 1 compression you have to pay the
price. .;-)
John




Actually, you can get an extra boost if you mix 1:4 ratio 100LL and
premium unleaded. Low concentrations of TEL yield large octane boosting.


Orval,
When you say "extra boost", what do you mean? If you mean power, you are
wrong. Higher octane is less explosive, harder to set off, less power,
that is the reason you don't get preignition. It won't ignite from high
compression, a glowing piece of carbon or early timing, etc as lower
octane will. To get the most power use the lowest octane you can with
out ignition knock.
L.D.

No, better to tune the engine to make use of the extra octane. Higher
CR, more advance, or better intake/exhaust can allow the engine to use
the extra octane and produce significantly higher power. High octane
fuel does not necessarily burn slower, it is just less prone to
auto-ignition.
Propane burns faster than gasoline and is 150 octane, on average.

I have had several vehicles over the years that produced enough extra
power (and therefore economy) on hightest to MORE than pay the
difference in cost. Being computer controlled engines, knock was never
an issue - I could likely have run the thing on Kerosene after it was
warmed up.

wrote:

On Tue, 13 Apr 2004 15:47:18 -0500, "L.D."
wrote:



Orval Fairbairn wrote:



In article . net,
UltraJohn wrote:





I double checked and it was Exxon and it is quite pricey. . .
regular 93 octane here is about 195 and this 110 leaded was 4.25 a gallon!
but hey if your running 12.5 to 13.0 to 1 compression you have to pay the
price. .;-)
John





Actually, you can get an extra boost if you mix 1:4 ratio 100LL and
premium unleaded. Low concentrations of TEL yield large octane boosting.




Orval,
When you say "extra boost", what do you mean? If you mean power, you are
wrong. Higher octane is less explosive, harder to set off, less power,
that is the reason you don't get preignition. It won't ignite from high
compression, a glowing piece of carbon or early timing, etc as lower
octane will. To get the most power use the lowest octane you can with
out ignition knock.
L.D.



No, better to tune the engine to make use of the extra octane. Higher
CR, more advance, or better intake/exhaust can allow the engine to use
the extra octane and produce significantly higher power. High octane
fuel does not necessarily burn slower, it is just less prone to
auto-ignition.
Propane burns faster than gasoline and is 150 octane, on average.

I have had several vehicles over the years that produced enough extra
power (and therefore economy) on hightest to MORE than pay the
difference in cost. Being computer controlled engines, knock was never
an issue - I could likely have run the thing on Kerosene after it was
warmed up.



Oh yes, I agree to tune the engine, higher cr, more advance and so on,
but that aggravates pre ignition. Then you may have to use higher
octane. I didn't mean to use lower octane instead of good tune. When you
do tune correctly and you still don't have pre ignition, then no need to
use higher octane. In fact it is counter productive. You said propane
has about 150 octane. I new it was very high although I didn't know the
exact #. That is my point, I have run propane in trucks and tractors
and it doesn't have as much power and it uses more fuel. So again my
belief is octane rating is not a power rating. If it was, burning
propane would give more power.
L.D.

On Wed, 14 Apr 2004 08:50:59 -0500, "L.D."
wrote:

Oh yes, I agree to tune the engine, higher cr, more advance and so on,
but that aggravates pre ignition. Then you may have to use higher
octane. I didn't mean to use lower octane instead of good tune. When you
do tune correctly and you still don't have pre ignition, then no need to
use higher octane. In fact it is counter productive. You said propane
has about 150 octane. I new it was very high although I didn't know the
exact #. That is my point, I have run propane in trucks and tractors
and it doesn't have as much power and it uses more fuel. So again my
belief is octane rating is not a power rating. If it was, burning
propane would give more power.
L.D.

Are you sure you mean to say "pre-ignition"? Pre-ignition is extremly
destructive, MUCH more so than detonation.

If an engine is at a high power setting and pre-ignition occurs, the
first indication would be sudden loss of power due to the
disintegration of the piston or some other equally catastrophic
component failure.

Pre-ignition is a spontaneous ignition of the fuel/air mixture prior
to when the spark plugs normally fire. That means the piston is still
on it's way up and the peak pressure point occurs before top dead
center. Very few engines can withstand this kind of internal pressure
for long before blowing.

Detonation, on the other hand, is a more rapid burning of the F/A
mixture after it's been normally ignited by the spark plugs. It also
results in higher peak pressure than normal because the burning of the
mixture occurs before the piston is at 16 degrees after top dead
center. But at least the piston isn't stil on it's way up.

Detonation can also be damaging to the engine, but it doesn't have to
result in damage, unless ignored for too long. This presupposes that
the engine is producing close to max power when the detonation occurs.
Detonation is almost impossible to produce with low power settings.

Also, in regards using higher octane fuel, if the engine's ignition
system is the type that varies the timing according to the information
gleaned from the various sensors on the engine, including a knock
sensor, then you would in fact be able to produce more power from that
engine by using a higher octane fuel because the ignition system would
max the timing settings when it doesn't sense any knocking going on.
When the system senses knocking, it retards the timing till the
knocking goes away.

Corky Scott

wrote:

On Wed, 14 Apr 2004 08:50:59 -0500, "L.D."
wrote:



Oh yes, I agree to tune the engine, higher cr, more advance and so on,
but that aggravates pre ignition. Then you may have to use higher
octane. I didn't mean to use lower octane instead of good tune. When you
do tune correctly and you still don't have pre ignition, then no need to
use higher octane. In fact it is counter productive. You said propane
has about 150 octane. I new it was very high although I didn't know the
exact #. That is my point, I have run propane in trucks and tractors
and it doesn't have as much power and it uses more fuel. So again my
belief is octane rating is not a power rating. If it was, burning
propane would give more power.
L.D.



Are you sure you mean to say "pre-ignition"? Pre-ignition is extremly
destructive, MUCH more so than detonation.

If an engine is at a high power setting and pre-ignition occurs, the
first indication would be sudden loss of power due to the
disintegration of the piston or some other equally catastrophic
component failure.

Pre-ignition is a spontaneous ignition of the fuel/air mixture prior
to when the spark plugs normally fire. That means the piston is still
on it's way up and the peak pressure point occurs before top dead
center. Very few engines can withstand this kind of internal pressure
for long before blowing.

Detonation, on the other hand, is a more rapid burning of the F/A
mixture after it's been normally ignited by the spark plugs. It also
results in higher peak pressure than normal because the burning of the
mixture occurs before the piston is at 16 degrees after top dead
center. But at least the piston isn't stil on it's way up.

Detonation can also be damaging to the engine, but it doesn't have to
result in damage, unless ignored for too long. This presupposes that
the engine is producing close to max power when the detonation occurs.
Detonation is almost impossible to produce with low power settings.

Also, in regards using higher octane fuel, if the engine's ignition
system is the type that varies the timing according to the information
gleaned from the various sensors on the engine, including a knock
sensor, then you would in fact be able to produce more power from that
engine by using a higher octane fuel because the ignition system would
max the timing settings when it doesn't sense any knocking going on.
When the system senses knocking, it retards the timing till the
knocking goes away.

Corky Scott


Corkey,
With the computer it is out of my league. In the old days, the way I
did it was correct. Now with the computer I still do not believe higher
octane will give more power. Take the old tractors in the 20'S. You
could burn gasoline or kerosene. Kerosene gave much more power and it is
lower octane. Like I said in my earlier post propane gives less power
and it has more octane. This is something I've saw happen.
I know I'm right because I've only been wrong once in my life and I was
mistaken about that. He He HE just joking.
Serious now. With the computer you may be able to get more power from
high octane, but I just don't see how.
L.D.

On Wed, 14 Apr 2004 08:50:59 -0500, "L.D."
wrote:

wrote:

On Tue, 13 Apr 2004 15:47:18 -0500, "L.D."
wrote:



Orval Fairbairn wrote:



In article . net,
UltraJohn wrote:





I double checked and it was Exxon and it is quite pricey. . .
regular 93 octane here is about 195 and this 110 leaded was 4.25 a gallon!
but hey if your running 12.5 to 13.0 to 1 compression you have to pay the
price. .;-)
John





Actually, you can get an extra boost if you mix 1:4 ratio 100LL and
premium unleaded. Low concentrations of TEL yield large octane boosting.




Orval,
When you say "extra boost", what do you mean? If you mean power, you are
wrong. Higher octane is less explosive, harder to set off, less power,
that is the reason you don't get preignition. It won't ignite from high
compression, a glowing piece of carbon or early timing, etc as lower
octane will. To get the most power use the lowest octane you can with
out ignition knock.
L.D.



No, better to tune the engine to make use of the extra octane. Higher
CR, more advance, or better intake/exhaust can allow the engine to use
the extra octane and produce significantly higher power. High octane
fuel does not necessarily burn slower, it is just less prone to
auto-ignition.
Propane burns faster than gasoline and is 150 octane, on average.

I have had several vehicles over the years that produced enough extra
power (and therefore economy) on hightest to MORE than pay the
difference in cost. Being computer controlled engines, knock was never
an issue - I could likely have run the thing on Kerosene after it was
warmed up.



Oh yes, I agree to tune the engine, higher cr, more advance and so on,
but that aggravates pre ignition. Then you may have to use higher
octane. I didn't mean to use lower octane instead of good tune. When you
do tune correctly and you still don't have pre ignition, then no need to
use higher octane. In fact it is counter productive. You said propane
has about 150 octane. I new it was very high although I didn't know the
exact #. That is my point, I have run propane in trucks and tractors
and it doesn't have as much power and it uses more fuel. So again my
belief is octane rating is not a power rating. If it was, burning
propane would give more power.
L.D.

You are missing the point.
An engine TUNED for high octane fuel will produce more power from each
gallon of that high octane gas, still below the "detonation" point,
than an engine properly tuned for low octane will on low octane.

It is also obvious you have never converted IC engines for propane in
a serious way. Propane has a lower energy content per lb than
gasoline, but if properly set up to take advantage of the octane
available in propane, the engine WILL produce significantly more power
than the original engine running on gasoline. Proper conversion of a
carbureted engine required cold manifolding, different plugs, modified
timing, among other things.

You WILL use more fuel.
Octane is NOT a power rating, but high octain fuel, while not CAUSING
an engine to produce more power, definitely ALLOWS it to.

On Wed, 14 Apr 2004 20:37:12 -0400, Bryan Martin
wrote:

in article ,
at wrote on
4/14/04 12:24 PM:


Also, in regards using higher octane fuel, if the engine's ignition
system is the type that varies the timing according to the information
gleaned from the various sensors on the engine, including a knock
sensor, then you would in fact be able to produce more power from that
engine by using a higher octane fuel because the ignition system would
max the timing settings when it doesn't sense any knocking going on.
When the system senses knocking, it retards the timing till the
knocking goes away.

Corky Scott


This is true if the engine is designed for the higher octane fuel (higher
compression ratio). If the engine is optimized for lower octane fuel, using
higher octane fuel will give no benefit and will probably result in slightly
lower power and economy. I seem to recall an oil company being sued for
false advertising for implying that their high octane fuel would give
improved performance in any vehicle.


That would be Sunoco. I remember putting Sunoco 120 in my Galaxie 500
that I'd shoehorned a 429 into.
--
dillon

Life is always short, but only you can make it sweet

L.D. wrote:

Higher octane is less explosive, harder to set off, less power,

I beg to differ. The statement that higher octane is "less explosive,
harder to set off" can be misleading. Less power is the obvious but
wrong conclusion.

Higher octane fuel burns relatively more slowly than a lower octane
fuel. Therefore it burns relatively cooler, the "controlled explosion"
is more evenly distributed throughout the combustion chamber. This
results in a relative power gain by using more and wasting less (power)
as well as preventing pre-ignition and detonation problems.

just my 2 cents worth.

AL

On Wed, 14 Apr 2004 03:51:16 GMT, wrote:

I have had several vehicles over the years that produced enough extra
power (and therefore economy) on hightest to MORE than pay the
difference in cost.


This story has been told many times before by would be experts.
It is the stuff of which Urban Legends are made.

There are many variables, but if one accepts that there is
a realistic 10% increase in horsepower from the use of
high compression pistons, the MAX SAVINGS is 10%....
IF regular and hi-test cost the same - and they don't.

Highly refined"HI-TEST" will never replace LOW GRADE
diesel when it comes to real power and economy.

There are more BTU's in a gallon of "regular" than HI-TEST.
There are even more BTU's per gallon available in DIESEL.

BTU's per gallon is the key to miles per gallon.


YMMV - pun intended