Oversize Pistons - JeepForum.com
LinkBack Thread Tools
post #1 of 3 Old 11-26-2001, 09:08 PM Thread Starter
Registered User
Join Date: Nov 2001
Location: Edmonton AB
Posts: 97
Oversize Pistons

I own a 1987 YJ 258 I6 with a 4.0L head swap. I'm sending the bare block down south next week to get cleaned and magnafluxed. Is it worth my while to overbore the cylinders to gain HP? If so, how much con I overbore the cylinders by and what size pistons will I need?

89' YJ
AMC 258, all mods
7" SOA BF 35" mud terrain
mde is offline  
Sponsored Links
post #2 of 3 Old 11-26-2001, 11:19 PM
Registered User
Join Date: Nov 2001
Location: KS
Posts: 318
Your best bet is to check with the machine shop doing the work to see what they think they can bore it out to. You better off just cleaning the cilinder wall and going with a little higher compression pistons to make the horse power. A good 9.5:1 or even 10:1 is nice but you will have to use premiem fule. But than again the price you pay for power.
eltj is offline  
post #3 of 3 Old 11-28-2001, 07:11 PM
Registered User
Join Date: Nov 2001
Location: Maine
Posts: 121
Even if you went with the biggest overbore pistons available 60 over or .062. Your 258 would only end up being a 267.
Buzzard is offline  

Quick Reply

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
help with pistons stormkaster Engines & Drivetrain 24 02-20-2010 10:49 AM
metric pistons? jeep795 Engines & Drivetrain 0 05-09-2009 07:37 AM
using chevy pistons in a 4.0 SuperStreetJeep Engines & Drivetrain 5 04-17-2009 10:16 PM
Pistons for 360 Mackddy6 Engines & Drivetrain 2 12-07-2001 08:28 PM
Pistons Mackddy6 Engines & Drivetrain 0 10-23-2001 08:52 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome