Advanced Engineering Tech For the more hardcore LS1TECH residents

Notching Top Of Cylinder Bore?

Thread Tools
 
Search this Thread
 
Old Jan 12, 2010 | 11:52 AM
  #1  
Mikey 97Z M6's Avatar
Thread Starter
11 Second Club
iTrader: (37)
 
Joined: Mar 2004
Posts: 2,046
Likes: 3
From: Vancouver, WA
Default Notching Top Of Cylinder Bore?

I was just curious if anyone has done this or not.

I have a set of cylinder heads that were used on a larger bore (4.125") so the combustion chambers were opened up for that larger bore. I blew that engine up late last season and I'm in the process of building a 6.0L shortblock (371ci) that will have a final bore size of 4.040". I was just wanting to know if anyone has notched the tops of the cylinder bores for a larger combustion chamber cylinder head to work on a smaller bore. I'm on a super-tight budget with this build, and would like to try to use these heads I already have instead of selling these and buying new ones etc... From what I can tell, I'd only need to notch the tops of the bores out about .030 - .050 more than final bore size. In other words, the combustion chambers measure about 4.090" across.

To give an example of what I'm talking about, here is a link:
http://www.turbomalibu.com/gn1r.htm

Mike
Reply
Old Feb 12, 2010 | 04:55 PM
  #2  
whitesmokels1's Avatar
On The Tree
iTrader: (4)
 
Joined: Aug 2004
Posts: 132
Likes: 0
From: Greenville, Texas
Default

Anyone think this is a good idea? I am toying with this idea as well on my build. Don't see how it could hurt, except lower compression.
Reply
Old Feb 13, 2010 | 09:05 AM
  #3  
Mikey 97Z M6's Avatar
Thread Starter
11 Second Club
iTrader: (37)
 
Joined: Mar 2004
Posts: 2,046
Likes: 3
From: Vancouver, WA
Default

Originally Posted by whitesmokels1
Anyone think this is a good idea? I am toying with this idea as well on my build. Don't see how it could hurt, except lower compression.
I didn't get any response on here so I talked to my machinist about this. He has an engine dyno and used to build stock car engines. He said he's seen it done but it only picks up 5-6hp (average) on old school SBC's. So,,, it definitely doesn't hurt as long as the head gasket clears the notches. I just got my block back from machining so I'll be doing this as soon as I finish up the rollcage.

Mike
Reply
Old Feb 13, 2010 | 09:41 AM
  #4  
Ed Wright's Avatar
9-Second Club
iTrader: (1)
 
Joined: Feb 2002
Posts: 3,397
Likes: 9
From: Tulsa, OK
Default

Been done since at least the late 1960s.
Reply
Old Feb 13, 2010 | 10:26 AM
  #5  
whitesmokels1's Avatar
On The Tree
iTrader: (4)
 
Joined: Aug 2004
Posts: 132
Likes: 0
From: Greenville, Texas
Default

Sweet. As they say "Every little bit counts"
Reply
Old Feb 16, 2010 | 06:13 AM
  #6  
jeejee's Avatar
Launching!
iTrader: (3)
 
Joined: Oct 2006
Posts: 250
Likes: 0
Default

not sure if this will work very well with the thin cilinderliners in an alu ls engineblock
might be a good option for the iron (truck) underblock though
Reply
Old Feb 16, 2010 | 09:03 AM
  #7  
Ed Wright's Avatar
9-Second Club
iTrader: (1)
 
Joined: Feb 2002
Posts: 3,397
Likes: 9
From: Tulsa, OK
Default

Originally Posted by jeejee
not sure if this will work very well with the thin cilinderliners in an alu ls engineblock
might be a good option for the iron (truck) underblock though
I agree.
Reply
Old Apr 28, 2016 | 10:41 PM
  #8  
xxxcorvette's Avatar
Teching In
 
Joined: Feb 2010
Posts: 11
Likes: 0
Lightbulb notching top of lq9 cylinder

Hey guys, I know this is an old thread, but I got my 4.030' block 6 liter back, and thought id post pictures of the valve interference with the cylinder walls. The funny thing is it appears the valves, don't interfere with the cylinder walls, until roughly .225" down the cylinder. The pictures show the marks, the very bottom of which are being pushed free, to the top of the valve guide, like 1.5" which is not realistic lift lol.My question has 2 parts...

How far down the cylinder wall would the valves travel from the seat with say an .051" ls9 head gasket?

And second, would it be okay to notch the cylinders above the said depth, to help clear/unshroud the valves???

Again I know this is an old thread, but I couldn't find much information, about this being done. Thanks again, please no critisizm, just advice......
Attached Thumbnails Notching Top Of Cylinder Bore?-left-bank.jpg   Notching Top Of Cylinder Bore?-right-bank.jpg  
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

 Brett Foote
story-1

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

 Pouria Savadkouei
story-2

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

 Verdad Gallardo
story-3

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-4

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

 Verdad Gallardo
story-5

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

 Pouria Savadkouei
story-6

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

 Verdad Gallardo
story-7

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-8

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-9

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo




All times are GMT -5. The time now is 03:29 AM.

story-0
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-04 18:13:20


VIEW MORE
story-1
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-2
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-3
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-4
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-5
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-6
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-7
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-8
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-9
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