Cylinder diameter VS. piston diameter - Page 3 - Hot Rod Forum : Hotrodders Bulletin Board -- Hot Rod Forum

Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
lost password?   |   register now

LinkBack Thread Tools
  #31 (permalink)  
Old 09-05-2010, 04:59 PM
ericnova72's Avatar
More for Less Racer
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 50
Posts: 13,262
Wiki Edits: 0

Thanks: 140
Thanked 1,761 Times in 1,493 Posts
Originally Posted by Custom10
OK so the coating must be 0.005 or so all the way round and it does actually squish down under some pressure, perfect fit, hmm LS1 magic,

So the middle is big and each end top/bottom is smaller?
Coating is thinner than that, but yes. you are correct.

Just some #'s for example off the top of my head, not in particular to the LS question, just general info:

Very bottom of skirt might only be .0005" smaller than the bore, but the top of the piston might be .010"-.015" smaller(some forgings are .035" smaller at the top) than the bore. A lot more thermal expansion at the top, this is why they are barrel shaped. Fattest part of the barrel shape is usually only about 1/2-1" above the bottom of the skirt.

Reply With Quote Quick reply to this message
Sponsored Links
  #32 (permalink)  
Old 09-05-2010, 05:18 PM
Custom10's Avatar
my KARMA ran over my DOGMA

Last journal entry: SS
Last photo:
Join Date: May 2009
Posts: 1,137
Wiki Edits: 0

Thanks: 27
Thanked 58 Times in 51 Posts
OK well good info, and really somehow these tight/interference fit motors work so thanks

Now with respect the OP

So my question is this: I know that a stock 350 has a bore of 4 inches right? So why am I measuring 4.020 - 4.030? Is this engine bored over? Or is the piston what's supposed to be 4 inches? If I were to replace the pistons, what "bore" would I purchase, and would that "bore" be referring to; the actual piston diameter, or the actual cylinder diameter?
Id say he could go with a 30 over slug and hone to fit? or should he get 40 over and really ruff it up?
Reply With Quote Quick reply to this message
  #33 (permalink)  
Old 09-05-2010, 09:31 PM
327NUT's Avatar
Registered User
Last photo:
Join Date: Dec 2004
Location: So. Utah
Age: 70
Posts: 3,414
Wiki Edits: 0

Thanks: 0
Thanked 123 Times in 110 Posts
Just so you guys know, the Op asked the question in regards to his bore vs. piston size on 1-28-10. I would think he had it figured out by now....maybe not.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last 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 email address for yourself.
Email Address:
Please select your insurance company (Optional)


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

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 On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Help with continuing master cylinder problem chris57 Suspension - Brakes - Steering 3 09-30-2003 02:35 PM
how to prepare a block blndweasel Engine 14 08-15-2003 12:28 PM
Compression Ratio advice new vortecs blndweasel Engine 8 06-11-2003 06:02 PM
Cam Help black66 Engine 3 05-12-2003 06:15 PM
Somebody stop me!!!! Mrfixmaster Suspension - Brakes - Steering 35 01-29-2003 06:45 AM

All times are GMT -6. The time now is 01:37 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999 - 2012. All Rights Reserved.