LT1-LT4 Modifications 1993-97 Gen II Small Block V8

milling heads

Thread Tools
 
Search this Thread
 
Old May 12, 2010 | 02:15 PM
  #1  
snk-huntr's Avatar
Thread Starter
TECH Enthusiast
iTrader: (2)
 
Joined: Dec 2006
Posts: 537
Likes: 0
Default milling heads

does having my heads milled up the compression any?
Reply
Old May 12, 2010 | 02:19 PM
  #2  
old93camaro's Avatar
TECH Resident
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (8)
 
Joined: Nov 2008
Posts: 778
Likes: 0
From: el paso, tx
Default

yea but head gasket helps as well
Reply
Old May 12, 2010 | 02:20 PM
  #3  
Vettestir's Avatar
12 Second Club
 
Joined: Jun 2005
Posts: 173
Likes: 0
From: Marysville. WA
Default

Yes but very little unless you take .03 or more off. It's best to take a light clean up maybe .005 to .010 off then run a thinner head gasket.
Reply
Old May 12, 2010 | 02:25 PM
  #4  
Gojira94's Avatar
TECH Fanatic
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (4)
 
Joined: Dec 2009
Posts: 1,194
Likes: 36
From: Clayton, NC
Default

Definitely... milling off more than .010 is probably not a good idea for a street setup

Here's a good article that talks about the procceses available:

http://www.aa1car.com/library/ar996.htm

Also look at how deck height affects compression. And piston shape, pin height, head gasket thickness, etc. etc.

Why do you ask?
Reply
Old May 12, 2010 | 02:25 PM
  #5  
Wicked94Z's Avatar
10 Second Club
iTrader: (26)
 
Joined: Jul 2005
Posts: 3,725
Likes: 1
From: Spokane, Wa
Default

lets think about this... you're milling the head, aka removing material to make the combustion chamber smaller. Yes that raises your CR.
Reply
Old May 12, 2010 | 02:36 PM
  #6  
snk-huntr's Avatar
Thread Starter
TECH Enthusiast
iTrader: (2)
 
Joined: Dec 2006
Posts: 537
Likes: 0
Default

I had 2 cracked heads and they were milled enough to where they knicked a valve on one head
Reply
Old May 12, 2010 | 02:42 PM
  #7  
Gojira94's Avatar
TECH Fanatic
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (4)
 
Joined: Dec 2009
Posts: 1,194
Likes: 36
From: Clayton, NC
Default

Oooouuch... must have taken a lot off. Did they tell you how much they had to take off? A thicker head gasket might have made the difference. Checking clearance with some clay is usually a good idea when you think you're going to be close. Different pistons is usually one way to solve it. I don't know if you can or should try to relieve the pistons' valve relief any more than they are, though I bet it's been done before...
Reply
Old May 12, 2010 | 02:45 PM
  #8  
GIZMO's Avatar
TECH Addict
iTrader: (8)
 
Joined: Jan 2004
Posts: 2,780
Likes: 3
From: Shelby, NC
Default

Originally Posted by snk-huntr
I had 2 cracked heads and they were milled enough to where they knicked a valve on one head
Who mills heads with the valves still in them?
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-1

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-2

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-3

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-4

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-5

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-6

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-7

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-8

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-9

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
Old May 12, 2010 | 02:52 PM
  #9  
snk-huntr's Avatar
Thread Starter
TECH Enthusiast
iTrader: (2)
 
Joined: Dec 2006
Posts: 537
Likes: 0
Default

didnt ask how much he took off , this was done last year and the car runs good just wondering if this helped or hurt power , mods are in sig , car runs 8.1 on motor and 7.30 on a 75 shot and my buddies keep thinking I have more done to it than what I say, haters ,lol
Reply
Old May 12, 2010 | 03:00 PM
  #10  
Gojira94's Avatar
TECH Fanatic
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (4)
 
Joined: Dec 2009
Posts: 1,194
Likes: 36
From: Clayton, NC
Default

Originally Posted by GIZMO
Who mills heads with the valves still in them?
x2... Just re-read and realized what was said. Well, I'd not be too happy about it, but if it's not creating a problem right now, I'd leave and start with different heads next time around. And use somebody else next time for the porting...
Reply
Old May 12, 2010 | 04:04 PM
  #11  
IronOutlaw's Avatar
TECH Fanatic
iTrader: (4)
 
Joined: Feb 2008
Posts: 1,443
Likes: 1
From: Athens, GA
Default

My old formulas heads were milled .080

had to "modify" the intake Manifold to get it to go back on. I had to run 93 in the car because it would diesal and spark knock with anything less.
Reply
Old May 12, 2010 | 04:25 PM
  #12  
jay7199's Avatar
TECH Resident
iTrader: (9)
 
Joined: May 2009
Posts: 809
Likes: 0
From: Austin/Cedar Park
Default

uhhh i wouldn't run anything less then 93 in any of my cars
Reply
Old May 12, 2010 | 05:39 PM
  #13  
Puck's Avatar
TECH Veteran
iTrader: (17)
 
Joined: Oct 2006
Posts: 4,152
Likes: 6
Default

My AFRs are getting .042 milled down, have huge valves, and are going on a zero decked block with a big, high lift cam.

I'm curious to the PTV I'll have .

Milling more then .010 on an SBC is not dangerous. You should always check PTV anyway...

BTW, each .005-.006 is around one cc drop in chamber size. You can only flat mill down around .050 before seriously screwing up your intake seal, but you can angle mill farther then that.
Reply
Old May 12, 2010 | 07:13 PM
  #14  
old93camaro's Avatar
TECH Resident
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (8)
 
Joined: Nov 2008
Posts: 778
Likes: 0
From: el paso, tx
Default

if you dont know how far they have been milled usually and i mean usually they stamp what they did on the head
Reply




All times are GMT -5. The time now is 02:34 PM.

story-0
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-1
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-2
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-3
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-4
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-5
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-6
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-7
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-8
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-9
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE