×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

CCR limit vs. Octane

CCR limit vs. Octane

CCR limit vs. Octane

(OP)
Not much activity here....time for a new thread:

OK, I was looking at some old notes on octane ratings describing four fuel ratings:

Motor Octane Number (MON)
Road Octane Number (RON)
Supercharge Octane Number (SON)
Research Method.

At the pumps I usually see a sticker that shows the (R+M)/M method to calculate the octane of the fuel.

The SON number really applies to aircraft fuels which exceed 100 octane running from one hundred to several hundred. It does not apply to unblown engines.
A non blown engine will start to lose power if the Octane exceeds about 100 MON or 104 RON (I remember 102 gas, anybody ever see 104 at the pump?). A 100 MON gasoline could easily handle a 15:1 compression ratio in most engines.

Because high octane fuel is a mixture of ingredients that want to ignite vs. ingredients that don't want to, we get fuel that is a compromise between what is acceptable for emmissions and for power/economy.

SO...your $64,000 question:

Because we build our engines to the available gasoline specs that are given us, are we at our limit?  

Not because we don't know how to build high compression, fuel burning marvels of technology. We've figured out how to control things like chamber temperature with EGR and the like, and we've increased efficiency with port injection, but because the formulation of fuel currently available can't handle anything above a certain parameter and until we either reformulate or change fuel delivery methods (DI ?) is this it?



Phasers

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources