Octane questions & discussion 2

[bobcat61]

Most discussions having to do with octane ratings of consumer gasoline usually end up with statements about more octane slows the burn rate or has a slower flame speed. I don’t subscribe to that as I prefer to think that higher octane fuels decrease the propensity of a fuel to auto-ignite with a comparable flame speed or burn rate to a lower octane fuel.

Usually, the discussions go on to say that unless the engine is tuned to benefit from the higher octane, you will loose power due to the slower burn. Again, I don’t necessarily accept that, preferring to think that any lost power is due to the lower heat content of the higher octane fuel.

I am aware that some of the more exotic “racing fuels (gasolines)” are fast burn mixtures but would like to discuss non-exotic gasolines with </= 100 octane.

Also, can anyone suggest information comparing flame speeds of gasoline, menthanol, tolulene etc.

BobCat

 

[Windsor377]

Have you ever spoken to the folks at Klotz?

http://www.klotzlube.com/

 

[MaxRaceSoftware]

http://www.superflow.com/flametemp/flame_temperature.html

Flame Temperatures
This program will find the theoretical flame temperatures either starting with the ambient temperature or starting with the temperature after the compression stroke but before the spark event. Although these are calculated values, and may not be the real temperatures in the combustion chamber, the differences between the values for various compression ratios, will remain constant, which can then be used as a guide for engine design. This is also true for the differences between the flame temperatures of the various fuels. D. Hill and Associates grant permission to copy and distribute this copyrighted program.


Download Flame Temperatures (56K)

http://www.superflow.com/Applications/ft.exe

this might help you a little ???


Larry Meaux (maxracesoftware@yahoo.com)
Meaux Racing Heads - MaxRace Software
ET_Analyst for DragRacers
Support Israel - Genesis 12:3

 

[patprimmer]

Interesting info Larry

I downloaded it and I am printing off a bunch of stuff from that site as I type

Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[MaxRaceSoftware]

Pat, its been a few years since i used that DOS program, from what i remember the program doesn't directly printout the info..at least the old version i have

all i did was just use the Edit/Mark/Copy and copy output to NotePad where it could be printed out

i used Courier New font, regular , 10 size

i ran a ton of different calculations using the program,
and used a Curve Fitting Program to develope equation, from what i remember the fit was 1.000 or so,
so Hill must have used a similiar routine to fit his data into program



Larry Meaux (maxracesoftware@yahoo.com)
Meaux Racing Heads - MaxRace Software
ET_Analyst for DragRacers
Support Israel - Genesis 12:3

 

[patprimmer]

Larry

I just tried to run it under win 2000

Accepts info, but shuts down when I enter all data.

I guess I had better dig an old machine out of mothballs and find an old copy of DOS and load it

Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[MaxRaceSoftware]

Pat , same thing here with Windows XP-Pro at home computer

you see for fleeting micro second results just before returning to windows..strange, i guess SuperFlow doesn't know of problems ??

runs perfect on Windows 98 Second Edition Plus C version
on Shop computer, in either full-screen DOS or Windows modes



Larry Meaux (maxracesoftware@yahoo.com)
Meaux Racing Heads - MaxRace Software
ET_Analyst for DragRacers
Support Israel - Genesis 12:3

 

[patprimmer]

I guess it does not like the NT file system, or the severely cut down version of DOS in Win 2000 and XP

Will try with old versions on old computer

Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[seymours2571]

You could try the following:

1) Click "Start" on the Start Bar.
2) Click "Run".
3) Type "CMD"
4) Finally, hunt down the program using dos commands and
execute it.

This method should prevent the window from closing once the
program has displayed its results.

Good luck,

Stephen Seymour

 

[MaxRaceSoftware]

1) Click "Start" on the Start Bar.
2) Click "Run".
3) Type "CMD"
4) Finally, hunt down the program using dos commands and
execute it.

This method should prevent the window from closing once the program has displayed its results.--Good luck, Stephen Seymour
===========================================

Works great on XP-Pro
thanks Seymour ...i forgot about those old DOS commands
and just type EXIT and hit enter key to quit DOS


Larry Meaux (maxracesoftware@yahoo.com)
Meaux Racing Heads - MaxRace Software
ET_Analyst for DragRacers
Support Israel - Genesis 12:3