Racing Fuel - yes/no ?
10-23-2009, 02:45 PM
#21
Racer
JMHO - I'm not a chemist or an engineer so this is strictly seat of the pants experience. I have a stock '66 427/425. If I run straight 93 pump fuel I get detonation under hard acceleration. If I add 5 gals of 110 racing fuel to about 15 gals of 93 pump fuel the pinging goes away.
Garth
Garth
10-23-2009, 03:14 PM
#22
JMHO - I'm not a chemist or an engineer so this is strictly seat of the pants experience. I have a stock '66 427/425. If I run straight 93 pump fuel I get detonation under hard acceleration. If I add 5 gals of 110 racing fuel to about 15 gals of 93 pump fuel the pinging goes away.
Garth
Garth
What is being discussed here is the myth of high octane gas having miraculous powers that can do everything include solve world climate change. For those that think that increased power will come from more aggressive timing advance, this might be possible if the advance curve was not optimized to start with, perhaps for emissions purpose. The concept of cranking more advance in ad infinitum is false. An over advanced engine will make less power than an under advanced engine even if no preignition is present. 36-38 degrees mechanical is the sweet spot.
10-23-2009, 04:27 PM
#23
Race Director
JMHO - I'm not a chemist or an engineer so this is strictly seat of the pants experience. I have a stock '66 427/425. If I run straight 93 pump fuel I get detonation under hard acceleration. If I add 5 gals of 110 racing fuel to about 15 gals of 93 pump fuel the pinging goes away.
Garth
Garth
10-23-2009, 06:42 PM
#24
Melting Slicks
I know the topic has no doubt been covered, probably many times.
But I am a newbie, with my "new" 1965 327/365 hp roadster. My car is running original drive train, with its 11.0:1 compression ratio, and I assume original valve seats. There is a dealer near me that sells 111, 113 or 118 octane leaded fuel, so I can obtain this with no trouble, and I can safely store small quantites of it.
What is the concensus of opinion regarding the value or detriment of mixing in a dose of this when I fill up, with normal 91 grade unleaded gas. Is there any down side for my engine? I am willing to accept the extra cost of the racing gas, and mild inconvenience of getting it, considering the car is a Sunday driver.
Thanking all in advance for your advice.
But I am a newbie, with my "new" 1965 327/365 hp roadster. My car is running original drive train, with its 11.0:1 compression ratio, and I assume original valve seats. There is a dealer near me that sells 111, 113 or 118 octane leaded fuel, so I can obtain this with no trouble, and I can safely store small quantites of it.
What is the concensus of opinion regarding the value or detriment of mixing in a dose of this when I fill up, with normal 91 grade unleaded gas. Is there any down side for my engine? I am willing to accept the extra cost of the racing gas, and mild inconvenience of getting it, considering the car is a Sunday driver.
Thanking all in advance for your advice.
BTW, the L76 cam had a very late closing intake valve so the dynamic compression ratio (DCR) is quite low and octane friendly.
10-23-2009, 07:51 PM
#25
Drifting
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My '67 Fiat 1500 has a thumb screw on the side of the distributor and a scale calibrated for octane. I use to autocross it. I'd adjust the thumbscrew, which changes the timing, for the octane I was using on a given day and would definitely see the difference. For what I was doing, I could take advantage of the higher octane and yes, I could feel the difference in the low end torque when using it.
When dealing with only 1438 CCs, it was easy to feel minor differences.
When dealing with only 1438 CCs, it was easy to feel minor differences.
10-23-2009, 08:04 PM
#26
Racer
Member Since: Apr 2008
Location: PASADENA CALIFORNIA
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I know the topic has no doubt been covered, probably many times.
But I am a newbie, with my "new" 1965 327/365 hp roadster. My car is running original drive train, with its 11.0:1 compression ratio, and I assume original valve seats. There is a dealer near me that sells 111, 113 or 118 octane leaded fuel, so I can obtain this with no trouble, and I can safely store small quantites of it.
But I am a newbie, with my "new" 1965 327/365 hp roadster. My car is running original drive train, with its 11.0:1 compression ratio, and I assume original valve seats. There is a dealer near me that sells 111, 113 or 118 octane leaded fuel, so I can obtain this with no trouble, and I can safely store small quantites of it.
Sense you have a good easy source for leaded race fuel, I would run it. Try 1/4 race fuel with 3/4 pump gas and see how you like it. It alse smells good, a lot better then our pump gas.
Enjoy,
Chris, CWPASADENA
10-24-2009, 01:27 AM
#31
Instructor
Member Since: May 2009
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65HIHP - read CW Pasadena's reply - he's right on point - 1/4 - 3/4 is his suggestion. You know I run 1 X 2.5 but I don't think you need that much leaded for your carb car.
10-24-2009, 11:50 AM
#32
Le Mans Master
Thread Starter
Leaded Hi Test blended with the crap fuel
"Since you have a good easy source for leaded race fuel, I would run it. Try 1/4 race fuel with 3/4 pump gas and see how you like it. It alse smells good, a lot better then our pump gas. " CWPasasdena
This advice makes perfect sense to me. I'm all over it.
thanks
This advice makes perfect sense to me. I'm all over it.
thanks
10-24-2009, 10:50 PM
#33
Irrespective of whether it helps at all, race gas has such a sweet smell. To me, at least. Gives my wife a headache.
10-25-2009, 09:11 AM
#34
Le Mans Master
Thread Starter
10-25-2009, 04:38 PM
#35
Le Mans Master
Your statement is correct (about resisting spontaneous ignition 
).
If an engine does not 'ping' on a given grade of fuel, raising the octane rating will not yield any benefits whatsoever other than possibly helping with percolation issues.
The myth that 'racing gas' will generate more power just won't die.
).If an engine does not 'ping' on a given grade of fuel, raising the octane rating will not yield any benefits whatsoever other than possibly helping with percolation issues.
The myth that 'racing gas' will generate more power just won't die.
