100 Octane

[goodnigh]

There is 100 octane gas available and I have considered using it.

At nearly $8 a gallon it is on par with European prices.

Question being will I need to change any tuning parameters

such as timing?

mike

 

[TommyK]

There is 100 octane gas available and I have considered using it.

At nearly $8 a gallon it is on par with European prices.

Question being will I need to change any tuning parameters

such as timing?

mike

Why do you think you need to run 100 octane fuel?

Octane is a case where more is not necessarily better.

 

[goodnigh]

There is 100 octane gas available and I have considered using it.

At nearly $8 a gallon it is on par with European prices.

Question being will I need to change any tuning parameters

such as timing?

mike

Why do you think you need to run 100 octane fuel?

Octane is a case where more is not necessarily better.

Hi Tommy,

Because that is what the engine was designed to use,

just curious. Also, no ETOH whereas pump gas here is 10%.

The engine is a barely broken in quench Cleveland with some

kind of cam. It responds noticeably to changes in temperature,

humidity and air pressure so we think it is properly tuned.

A physician I work with has one of those 600 HP Mercedes

and he uses it, car runs a lot better he says.

mike

 

[Bill73Ragtop]

To answer the original question, no changes required. You may find it runs a tiny bit smoother , but not much else will change.

 

[will e]

If it pings a little the additional octane might help. You can mix it with your regular octane gas to save money.

For example: 8 gallons of 92 plus 8 gallons of 100 will net you about 96 overall octane.

 

[c9zx]

here is an informative link. http://www.prosystemsracing.com/scoop040909.html

Current US octane rating method is RON+MON/2.

Old US octane rating method was RON (used in the 60s and early 70s).

RON+MON/2 96 octane is approximately equal to RON 100 octane.

Chuck

 

[72HCODE]

Higher octane just means it takes more to ignite the fuel.

Nothing is going to happen if you put 100 octane fuel in the car. It will run the same as if you put regular gas in the tank.

The higher octane level will allow you to tune the motor with more timing as it will take more to make the engine start to ping/detonate. More timing means more power.

So if you want to retune the motor for increased performance then higher octane will have an effect.

If your engine does not ping running 87 octane then you can increase timing on lower octane fuel and gain performance, without spending all the money on 100 octane fuel.

Besides increasing octane to allow for more timing you can also increase the amount of fuel getting into the cylinders.

This is why higher octane usually increases mpg. Since the higher octane has a higher ignition threshold you can lean a motor out reducing its fuel consumption and it will not ping /detonate.

Ethonal fuel has a higher octane rating, but has a lower energy release then normal gas. So you get this weird situation where you can run more timing but you need more fuel also.

Just a basic overview of octane here, but using racing fuel in street car that is not tuned to the edge of detonation is a waste of money.

 

[goodnigh]

Thanks for all the advice, now I am going to have to try it

Will let you know if it makes any difference, this is not a "stock"

Cleveland.

mike

 

[rocket366]

I'm kinda happy that my 351C is a 2v open chamber headed motor!

I run lots of advance on 87 octane fuel and the car has PLENTY OF POWER!