250 compression - Chevy Nova Forum
Visit our sponsor, National Nostalgic Nova
 
Steve's Nova Site is an automotive enthusiast website dedicated to the 1962 - 1979 Chevrolet Nova, Chevy II and Acadian automobiles. We work together to preserve, restore, drive, show, race and provide fellowship for these classic cars. This is one of the best places to find information about parts, rebuilding, restoration and racing. This website is not affiliated with GM, General Motors or Chevrolet in any capacity.

Go Back   Chevy Nova Forum > Body, Chassis and Mechanical > Drivetrain & Performance


StevesNovaSite.com is the premier Chevrolet Nova Forum on the internet. Registered Users do not see the above ads.
Reply
 
Thread Tools Display Modes
Old 4th-July-2008, 07:24 PM   #1
Richardlss
 
Richardlss's Avatar

Title: Nova Guru
iTrader: (0)
Status: Offline
Join Date: Jan 2006
Location: Illinois
Nova(s): 1978 Nova
Posts: 1,172
250 compression

with a stock 250 the compression should be 8:1... but im getting the head milled, taking .30" (i think its .30") with that small of a number how much difference does it make in compression?
  Reply With Quote
Sponsored Links
Advertisement
 
Old 4th-July-2008, 09:33 PM   #2
Twisted6
 
Twisted6's Avatar

Title: Nova Guru
iTrader: (1)
Status: Online
Join Date: Apr 2004
Location: Daytona B fla.
Nova(s): 64 SS chevyII
Posts: 932
that will bring you to ruffly 8.5-1 you gain about 2 points in compression for every .010 off the head.
__________________
T6R }[oooooo]
www.t6racing.org/id6.html
Larry /aka Twisted6
  Reply With Quote
Old 4th-July-2008, 09:56 PM   #3
Richardlss
 
Richardlss's Avatar

Title: Nova Guru
iTrader: (0)
Status: Offline
Join Date: Jan 2006
Location: Illinois
Nova(s): 1978 Nova
Posts: 1,172
what is the normal mill thickness people usually get shaved off their heads?
i finally found a calculator for compression ratio's and it said to get 9.1 compression i need to take off 0.048"...
wouldnt that be 8.8-1? unless its just rounded off?
  Reply With Quote
Old 4th-July-2008, 10:59 PM   #4
Nova_Power4
 
Nova_Power4's Avatar

Title: Nova Guru
iTrader: (0)
Status: Offline
Join Date: May 2007
Location: thunder bay
Nova(s): 77 NOVA,97 F-150 lariat
Posts: 933
wow if thats the case, whats my compression then!?!?!?! .100thow off my head block combined
__________________
1977 Nova,250-Turbo Inline6
That dont please ya..I'm fromYou Hooser
"AS WE SLEEP THEY DIE"
  Reply With Quote
Old 5th-July-2008, 12:02 AM   #5
Richardlss
 
Richardlss's Avatar

Title: Nova Guru
iTrader: (0)
Status: Offline
Join Date: Jan 2006
Location: Illinois
Nova(s): 1978 Nova
Posts: 1,172
Quote:
Originally Posted by Nova_Power4 View Post
wow if thats the case, whats my compression then!?!?!?! .100thow off my head block combined
you had your head milled .100? what is the difference in horsepower do you know? i've been trying to figure out how much horsepower gain i could get out of 8.1 compression to 8.5 compression, if theres a good amount of gain, id probably just step up to 9.1 compression
  Reply With Quote
Old 5th-July-2008, 07:33 AM   #6
Nova_Power4
 
Nova_Power4's Avatar

Title: Nova Guru
iTrader: (0)
Status: Offline
Join Date: May 2007
Location: thunder bay
Nova(s): 77 NOVA,97 F-150 lariat
Posts: 933
l had 50thou off the head then 50 off the block when it was getting milled.
power wise l dontr know but l got alot of torque drop it in 2nd gear do donuts alllll day
but l'v worked the motor of just a tad bit more also running 97prem
__________________
1977 Nova,250-Turbo Inline6
That dont please ya..I'm fromYou Hooser
"AS WE SLEEP THEY DIE"
  Reply With Quote
Old 5th-July-2008, 02:03 PM   #7
Richardlss
 
Richardlss's Avatar

Title: Nova Guru
iTrader: (0)
Status: Offline
Join Date: Jan 2006
Location: Illinois
Nova(s): 1978 Nova
Posts: 1,172
hm.... i may try seeing if i can get head milled .40 and block .40 that should get me 9.1 the way it sounds from larry...
  Reply With Quote
Old 5th-July-2008, 06:16 PM   #8
Twisted6
 
Twisted6's Avatar

Title: Nova Guru
iTrader: (1)
Status: Online
Join Date: Apr 2004
Location: Daytona B fla.
Nova(s): 64 SS chevyII
Posts: 932
It may have just rounded it off,I don't know for sure. I have it in notes somewhere when i was told. and i am pretty sure it was like 2 points for every .010 milled. When I get a half a chance I'll call the guy again just to double check and make sure i am remembering it right. But the call will have to wait till monday.
__________________
T6R }[oooooo]
www.t6racing.org/id6.html
Larry /aka Twisted6
  Reply With Quote
Old 6th-July-2008, 10:16 AM   #9
Richardlss
 
Richardlss's Avatar

Title: Nova Guru
iTrader: (0)
Status: Offline
Join Date: Jan 2006
Location: Illinois
Nova(s): 1978 Nova
Posts: 1,172
Hey guys, i cant really find a good compression calculator, so i was wondering if any of you knew a good one to get?
just trying to figure out how much HP gain im getting
block is stock with the 3.875x3.53 bore/stroke
74CC head
not sure gasket thickness
but the head is getting milled probably .030" or .040"
and also the block may be getting milled .030" or .040"
if .010" is 2 points of compression then the total .060" is 9.2-1 and .080" is 9.4-1 right?
just getting excited about more compression for some reason
  Reply With Quote
Sponsored Links
Advertisement
 
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Cranking Compression Repointer Drivetrain & Performance 7 26th-October-2007 06:41 PM
Compression Ratios and Pump Gas Kurt Drivetrain & Performance 8 26th-October-2007 02:19 AM
Cam and Compression for my 383 Scooter Drivetrain & Performance 12 20th-February-2007 11:44 PM
Tuning problems 63SLEEPER Drivetrain & Performance 53 30th-August-2006 08:44 PM
Compression ratio, DCR and pump gas (merged threads) 69NovaSS Best of Drivetrain & Performance 166 2nd-August-2006 09:07 PM


Site best viewed set to 1024 x 768.

All times are GMT -4. The time now is 06:29 PM.

Custom Designed for Steve's Nova Site by: vBSkinworks

 
Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Lt

Garage Plus vBulletin Plugins by Drive Thru Online, Inc.