Xylene or Toluene Octane Boost? 1

[nuker]

I have found multiple "Homebrew Racegas" articles. The majority recommend Toluene as an aromatic. Xylene is also listed and has similar properties. It seems that Toluene has been preferred for cost savings (at the time the arcticle was written). Xylene is now more affordable and would yield the same actane with lower ratios due to higher octane {(R+M)/2}.

Question: Are there any drawbacks to using Xylene over Toluene?

Note: High pressure application (up to 26psi).

 

[drwebb]

Sorry Jim,
I mis-read your post as describing a colligative effect raising the freezing point of the heavy fractions (as with a flow improver), when at trace concentration you probably referred to solvation effects.

 

[jhillyer]

Right, and similarly, the various structures, some wide, some long, help the higher vapor pressures stay in liquid solution.

 

[jhillyer]

"drwebb (Automotive) Jan 16, 2003
I don't suppose it is an issue in a low-mileage race engine, but I suspect that such high aromatic content gasoline could lead to greatly increased combustion chamber deposits (CCDs) over the miles, and diluting the detergency of the pump gas likely will promote intake valve deposit formation and possibly even fuel injector fouling."

I do hope those that use anything suspect, will be just as diligent in treating and maintaining equipment, so injector fouling would be a minor and temporary inconvenience with simple inexpensive remedies.

 

[sciguyjim]

jhillyer,
Aromatics do promote CCDs, when used long term, because they are notorious soot producers.

 

[ShaunT]

Chevron offers their Techron over the counter and intends it to be used on occasion at 1oz per gal. It's a great detergent when used with 93.

Shaun Tiede ULTRADYNE Arlington,TX

 

[grogg]

dont know if this this will work for you, we need both. if we run with only toluene mixed in the exhaust temp climes too high, with only xylene - detonation. i think the xylene brings down the exhaust temp and toluene boosts the burn rate and octane.

we also found that without accetone the fuels do not mix propperly.?

no starting problems, also high boost and high cr.