×
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

Pumps Gas or High Octane

Pumps Gas or High Octane

Pumps Gas or High Octane

(OP)
I got a 1500 cc DOHC has a blower producing 250hp with 11.4 psi STOCK. it  has in 7.8 to 1 ratio but i want to put in 9.5 to 1 pistons without going to high octane..is this posible and is so what can i do?  

RE: Pumps Gas or High Octane

Based on the void of relevant data, not likely

Run 100 octane or more and/or knock sensors and/or water injection and keep your fingers crossed.

 

Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers for professional engineers
 

RE: Pumps Gas or High Octane

FastKaz,

a CR change of 7.8 to 9.5 really is a major step and one which it sounds like you are ill prepared to make.

Why on earth are you prepared to make a radical change to your engine but are against using higher octane fuel?

There are many things that you can do to make running with that setup 'safer' and Pat has already started the ball rolling (though he must be in a good mood today to even bother repying to your post!).

My suggestion would be to go away and Google what effect the change in CR is going to have on your engine, learn a little about it - then come back with some more specific questions.

MS

RE: Pumps Gas or High Octane

Well, I'm glad you "got" one...However, the changes you are anticipating to make will almost guarantee that you will likely not have one very much longer. sad

Rod

RE: Pumps Gas or High Octane

(OP)
thanks for the information.. my son is into racing with jet ski and  i was just wondering

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