octane/HP rumors?

[The Deuce]

I understand what he is trying to say as well.

He wants to hear a yes to a question that the answer is no. All things being held equal, there IS NO gain from 93. Period.

If I do nothing but hook up a 150 dry shot, I'm going to see extra power until I blow the motor. Same with a blower. Not the same with 93. It just doesn't happen like that.

[gizmo83]

i do not want a yes when the answer is no.. i give up. if you'd read the posts you'd know that i understand higher octane HELPS to up power (by allowing timing adjustments/higher compression/ect). and that i know IT DOES NOT DO ANYTHING BY ITSELF. like srv1 said: we are all talking about the same thing and getting nowhere.

[rppngears]

I always use 93 octane in my 91 5.0 because I was under the impression that it is better for my engine because of all the detergents it contains. I've run 89 before with no problem, I just usually opt for the 93. After reading this post particularly what prkwud stated I now think I might actually be doing my engine harm. Is this right? Should I use the 89 octane from now on? I'm not trying to get any horsepower gains from using either one, I just want to use whatever is better for my engine. I do have my timing slightly advanced, but like I said there is no knocking when I use 89.

[Mr 5 0]

rppngears:

I see no real harm in using 93 octane (I use 94 and in 12 years I've never had the slightest gas-related problem) but as PKRWUD stated, running the lowest octane you can - without detonation - is probably the best way to go. If you can run advanced timing with 89 octane, go for it. If you can do it with 87, better yet. Experiment. My Mazda 2.0 runs 2-degrees advance with 87 octane, my Mustang won't do that and requires more. Every engine is different.

The gas companies do claim the higher octane gas contains extra 'detergents' to help keep injectors clean. This sounds plausable and my injectors are clean after well over 100,000 miles of using 94 octane but I've also heard this is BS to sell higher octane gas which also sounds plausable.

I basically ignore the 'detergent' factor (but suspect it's true from my own long-term experience) and just crank up the timing and fill up with Sunoco Ultra 94 every week. Works for me.

[PKRWUD]

FWIW, there are only 3 or 4 sources for the gasoline you buy, and they are pretty much the same. Brand loyalty means very little, and the detergent issue is purely for show. To date, there has not been a gasoline additive made that will clean dirty injectors. It's mcalled hype. The chemicals needed to clean the injectors would damage other parts of the fuel system, namely the pump. The only method that will clean the injectors on the car is called Motorvac, and it's very expensive.

Take care,
~Chris

[SlowGT]

PKRWUD: That's one of the most down to earth, easy to understand explanations I've ever heard about octane. I've read all the 'technical' explanations and never quite put it all together before. I've understood it well enough to select the appropriate fuel for my vehichles, but never knew enough to be able to explain it to anybody else.
THANKS.


For future reference, oxygen by itself is nonflammable. For a simple proof of this, try to light an oxy-acetylene torch without the gas turned on.

Kind of makes the NOS explosion on the F&F a little lame, huh?

Peace

[bigred90gt]

Given the fact of where you are from, I doubt that you would have heard this. About 8 or 9 yrs ago, we had a really devistating flood in Baytown, home to the company Exxon. We are located right on the water. There is a plant right off the freeway that sells and transfers pure oxygen via large diameter piping run throughout the country. As the flood waters rose, so did a section of pipe that was carrying the oxygen. Once the pipe finally gave way, and the oxygen escaped, there was a massive explosion that rocked our world. That having been said, I have to disagree with you when you say that oxygen is not flammable.

[PKRWUD]

Thank you very much! That is one of the nicest compliments I can ever get! I love knowledge, but I really love sharing it with people, and being able to do it in a way that most people will understand.

Thanks.

Take care,
~Chris

[SlowGT]

You're welcome. I've picked up a tip or 2 from your posts in the past.




I figured I'd have some nonbelievers when it came to the properties of oxygen. I don't know what happened in TX, but I can assure you that no oxygen burned/exploded by itself. If you had a flood around a refinery, I'm guessing there was probably some flammables floating on the water that the pipe was in. The pipe broke (causes a spark), the fuel was ignited and the presence of oxygen caused an explosion ten times worse than the flammables alone could've produced.

I'm not posting this to be a 'know-it-all', because I'm certainly not the sharpest knife in the block, but I'm pretty well versed when it comes to industrial gases. It's a huge misconception advocated by TV/Hollywood. I've got years of experience with this stuff. Why would I lie? Without being able to give you a personal demonstration, the following websites are the best I could do. They are the MSDS sheets from 2 of the 3 world leaders in industrial gases (Air Products and BOC Gases). I'm a former employee of the 3rd (Praxair) but I couldn't find one of their's.

Check out the 1st page:
http://avogadro.chem.iastate.edu/MSDS/oxygen.pdf

See page 2 here under NFPA & HMIS Hazards and page 3 under 'Fire Fighting Measures':
http://www.mwsc.com/MSDS/21.PDF

If you still don't believe me, call your local welding supply shop and ask them. Better yet, go down there and tell them you'd like to see what color is emitted when oxygen burns.

Once you believe, share it with all your buds.

Peace and safe street racing to all

[bigred90gt]

I stand corrected. All I know is what I was told. As far as I know, that could have been a company covering up a major screw-up. I think Sec. 5 of the first MSDS sheet could have something to do with it. Thanks for the clarification.

[Lethal5Oh]

If oxygen was flammable we'd all be dead right now. One spark and the whole world would be gone.

[PKRWUD]

Originally posted by Lethal5Oh
If oxygen was flammable we'd all be dead right now. One spark and the whole world would be gone.

Not quite. Our air isn't pure oxygen. If it was, the planet's atmosphere would explode.

Oxygen in and of itself is not flammable, but it will make vitrually anything it comes in contact with extremely flammable. See the pic below. It's the label on the O2 bottle in my garage. It states clearly that it VIGOROUSLY ACCELERATES COMBUSTION.

Take care,
~Chris

[PKRWUD]

Schit. Forgot the picture.

[eatsgmcar]

If the car is running fine with 87 octane gas but for a
stupid reason i change to premium gas (93 octane)

Am i going to notice a higher ET at the track? I just want
to know if i could be penalized for using too much octane.

I have ever tried to advance the timing to 18 and i never
heard any strange noise from the motor. (using premium gas)
I now keep it at 14. I ll certainly try to use the 87 octane rated
gas.

[Hethj7]

First off I understand the whole octane/power thing, so that is not what this question is about. And yes, Chris does an excellent job of explaining a lot of things. Thanks!

Out of curiosity though, are newer computers in cars able to "read" what octane is coming through the system and then advance timing if it is able to?

I ask because I remember an old episode of Horsepower TV where the two guys both were racing Mustangs. The older guy put octane booster in his tank at the track and stated that the car's computer would see the extra octane and advance the timing accordingly. Does this actually happen, or is it just TV BS?

[PKRWUD]

That ability has been around for a while, and is done via the knock sensor, but very few ECM's actually take it to it's extreme. basically, the ECM has programed curves in it, and it will advance or retard the timing depending on which of it's many preprogramed curves the sensor signals are telling it to follow. If it senses a signal from the knock sensor before reaching the preprogramed max ignition advance, it will not continue to advance, and theoretically that could mean never reaching your potential. But, this is very unlikely, unless you have already advanced the timing, and are deceiving the ECM.

There are no cars in production, that I am aware of, that will just keep advancing the timing until it knocks. They all have preprogramed limits.

Take care,
~Chris

[1969Mach1]

Ok I'm going to be a post ***** and skip abit of that conversation, I read what you wrote Chris and I think you explained that to me awhile back and I completly understand and not going agaist you cause I don't know the difference between my a*s and a hole in the ground when it compares to you. But I'm having a Mallory Distributor put in my car (351-4bbl), what should I set the timing too? More the less curious what exactly the timing does to the car, I'm hoping to get my car dyno'd so I want to set it to something reasonably good. Like is it unstable if I put my timing to something in mid 20's or just keep it at 16? And what would determine what I set it too? Like what part done to the engine.
This is the distributor I am having put in.
Mallory Distributor

I'm also having a MSD Ignition put in with it, and intake and new Holley 650 DP DF Carb too but I'm not sure if that matters.

Thanks,
sorry again if it was already asked I'm just alittle slow....

§am.

[srv1]

Originally posted by PKRWUD


Not quite. Our air isn't pure oxygen. If it was, the planet's atmosphere would explode.

.

Take care,
~Chris [/B]

that is correct. as a matter of fact, we breath mostly nitrogen. about 70% of the air we breathe.

[PKRWUD]

The ignition timing is when the spark plug fires in relation to where the piston is in it's travel. Zero degrees timing means that the spark occurs exactly when the piston reaches it's uppermost point of travel. That's no good when the rpms are going.

DO NOT BUY THAT DISTRIBUTOR!!!!!!!

Please do not waste your money on that piece of schit. Let my mistake be your gain. If you are getting an MSD box, get an MSD 8584. You're looking at about $300, +/-. TRUST ME.

I'm going to tell you right now the best way to set your timing. See, there is no single answer. Any and every mod a vehicle has done to it can affect what the timing should be set to. This is the simplest way to do it.

You will need a timing light, a tach, some liquid paper, and a vacuum gauge.

First, make sure the carburetor is adjusted correctly.

2) Remove and plug the vacuum advance hose, if it has one.

3) Mark the 10 degree mark and the tip of the pointer with liquid paper.

4) Hook up the timing light.

5) Loosen the distributor so you can turn it, then snug the bolt 1/8th of a turn.

6) Attach the vacuum gauge to a source of manifold vacuum.

7) Hook up the tach.

8) Start the engine, and check with the timing light to see where it is.

9) Adjust it to 10 degrees BTDC.

10) Check the tach and note the rpms, and check the vacuum gauge and note the reading.

11) With the hold down bolt loose, SLOWLY rotate the distributor while watching the vacuum gauge. Turn it which ever direction it is that makes the needle on the gauge go up.

12) Keep doing this until it no longer moves up. If you're not sure when it reaches it's peak, use the tach to tell you.

13) rotate the distributor the OPPOSITE direction, so that the needle on the vacuum gauge starts to drop. When it get's to a half inch of mercury lower than it was at it's peak (ie: if it's peak was 18". lower it to 17.5"), tighten the hold down bolt.

14) Check with the timing light to see where it's at now, and write that down.

Now's the fun part. Go for a test drive, and get on it. TRY to make it ping! if it does, then retard the timing one degree and test it again.

Take care,
~Chris

[srv1]

Originally posted by PKRWUD
To date, there has not been a gasoline additive made that will clean dirty injectors. It's mcalled hype. The chemicals needed to clean the injectors would damage other parts of the fuel system, namely the pump. The only method that will clean the injectors on the car is called Motorvac, and it's very expensive.

Take care,
~Chris

Chris, tell me this. I have been using Chevron Techron Concentrate in my car and customers cars for years. It works superbly. It actually corrected some running problems. How did this work without harming any injectors or any part of the fuel system? I still use it to this day.

As for dirty injectors, as far as i know, there is nothing that can clean actual "dirt" out of an injector. Maybe some other contaminents, but not dirt. If chemicals can break down dirt, say bye-bye to whatever that substance touched in your fuel system.
Motorvac is expensive, but it does work.