C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Compression Ratio?

Thread Tools
 
Search this Thread
 
Old Aug 14, 2002 | 08:35 PM
  #1  
UB2 SLOW's Avatar
UB2 SLOW
Thread Starter
Burning Brakes
 
Joined: Jul 2002
Posts: 822
Likes: 0
From: I could tell but then I would have to kill you
Default Compression Ratio?

With the below listed mods, what can I expect the compression ratio to be. The stock compresson is 10.4.
Reply
Old Aug 15, 2002 | 05:52 AM
  #2  
gtsyellow's Avatar
gtsyellow
Melting Slicks
 
Joined: Apr 2002
Posts: 3,019
Likes: 0
From: down that one road next to that big tree
Default Re: Compression Ratio? (UB2 SLOW)

ask the guy who did your heads if they were decked. if they were not decked your compression is the same as stock or maybe 0.1 less from the chambers being worked.
Reply
Old Aug 15, 2002 | 12:52 PM
  #3  
SPD DMN's Avatar
SPD DMN
Le Mans Master
20 Year Member
 
Joined: Oct 1999
Posts: 9,713
Likes: 3
From: Sachse Texas
Cruise-In I Veteran
Cruise-In II Veteran
Default Re: Compression Ratio? (UB2 SLOW)

If you went from a ~56-58 cc head to a 54.4 cc head, and nothing else changed, you probably added .2-.3 points. So you are probably somewhere in the vicinity of 10.6-10.7.

Here is one calculator...
http://www.rbracing-rsr.com/compstaticcalc.html
Reply
Old Aug 15, 2002 | 06:00 PM
  #4  
UB2 SLOW's Avatar
UB2 SLOW
Thread Starter
Burning Brakes
 
Joined: Jul 2002
Posts: 822
Likes: 0
From: I could tell but then I would have to kill you
Default Re: Compression Ratio? (gtsyellow)

ask the guy who did your heads if they were decked. if they were not decked your compression is the same as stock or maybe 0.1 less from the chambers being worked.
The guy is doing the heads now. I should get them back next week. What is decked?
Reply
Old Aug 15, 2002 | 06:45 PM
  #5  
65Z01's Avatar
65Z01
Team Owner
20 Year Member
 
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Default Re: Compression Ratio? (UB2 SLOW)

He will shave a little off the heads where they attach to the block to assure flatness. If he takes off more than a few .001s he may need to also shave the intake base to assure a good matchup.
Reply
Old Aug 15, 2002 | 08:30 PM
  #6  
gtsyellow's Avatar
gtsyellow
Melting Slicks
 
Joined: Apr 2002
Posts: 3,019
Likes: 0
From: down that one road next to that big tree
Default Re: Compression Ratio? (65Z01)

isn't 54cc the stock lt4 chamber?
Reply
Old Aug 15, 2002 | 08:42 PM
  #7  
Sharky Guam's Avatar
Sharky Guam
Safety Car
 
Joined: Feb 2002
Posts: 4,286
Likes: 4
From: Guam
Default Re: Compression Ratio? (gtsyellow)

You're probably not going to realize much of a difference. A couple cc's won't affect any noticeable change.

Be sure to mill the intake to match the heads. If your ports are mismatched, you will likely notice a loss.

:cheers:
Reply
Old Aug 15, 2002 | 10:00 PM
  #8  
UB2 SLOW's Avatar
UB2 SLOW
Thread Starter
Burning Brakes
 
Joined: Jul 2002
Posts: 822
Likes: 0
From: I could tell but then I would have to kill you
Default Re: Compression Ratio? (Sharky Guam)

You're probably not going to realize much of a difference. A couple cc's won't affect any noticeable change.

Be sure to mill the intake to match the heads. If your ports are mismatched, you will likely notice a loss.

:cheers:
He has my intake, heads and the trottlebody. He is going to port & polish and make sure everything is matched. I am hoping for some serious flow. I ran the setup on Dyno 2000 software with 10.4 compression and it gave me 365 hp at 5500 and 435 tq at 4000. I am not sure how accurate the software is. After I get the actual flow numbers I will put them in and check again.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-1

2027 Corvette vs The World: Every Model vs Closest Competitor

 Joe Kucinski
story-2

10 Most Common Corvette Problems of the Last 20 Years!

 Joe Kucinski
story-3

5 MOST and 5 LEAST Popular Corvette Model Years in History!

 Joe Kucinski
story-4

2027 Corvette Buyer's Guide: Everything You Need to Know!

 Joe Kucinski
story-5

10 Things C8 Corvette Owners Hate (But Won't Tell You)

 Joe Kucinski
story-6

10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!

 Brett Foote
story-7

Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)

 Joe Kucinski
story-8

Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!

 Michael S. Palmer
story-9

5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!

 Joe Kucinski
Old Aug 15, 2002 | 10:06 PM
  #9  
Glasman66's Avatar
Glasman66
Drifting
20 Year Member
 
Joined: Apr 2001
Posts: 1,403
Likes: 0
From: Denver CO
Default Re: Compression Ratio? (UB2 SLOW)




He has my intake, heads and the trottlebody. He is going to port & polish and make sure everything is matched. I am hoping for some serious flow. I ran the setup on Dyno 2000 software with 10.4 compression and it gave me 365 hp at 5500 and 435 tq at 4000. I am not sure how accurate the software is. After I get the actual flow numbers I will put them in and check again. [/QUOTE]

What is he charging you. I want to do the same and was wondering what it should run?
Reply
Old Aug 16, 2002 | 10:47 AM
  #10  
UB2 SLOW's Avatar
UB2 SLOW
Thread Starter
Burning Brakes
 
Joined: Jul 2002
Posts: 822
Likes: 0
From: I could tell but then I would have to kill you
Default Re: Compression Ratio? (Glasman66)


What is he charging you. I want to do the same and was wondering what it should run?[/QUOTE]

He is charging me $500.00 for the whole thing. His web site is http://www.actionautomotiveinc.com.
Reply

Get notified of new replies

To Compression Ratio?





All times are GMT -4. The time now is 05:41 PM.

story-0
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-1
2027 Corvette vs The World: Every Model vs Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-20 17:58:41


VIEW MORE
story-2
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE
story-3
5 MOST and 5 LEAST Popular Corvette Model Years in History!

Slideshow: 5 most and least popular Corvette model years.

By Joe Kucinski | 2026-04-08 13:25:01


VIEW MORE
story-4
2027 Corvette Buyer's Guide: Everything You Need to Know!

Slideshow: 2027 Corvette buyer's guide

By Joe Kucinski | 2026-04-17 16:41:08


VIEW MORE
story-5
10 Things C8 Corvette Owners Hate (But Won't Tell You)

Slideshow: 10 things C8 Corvette owners hate, but won't tell you.

By Joe Kucinski | 2026-04-01 18:36:07


VIEW MORE
story-6
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!

Slideshow: Should you add one of these incredible Corvettes to your garage?

By Brett Foote | 2026-04-01 18:14:05


VIEW MORE
story-7
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)

Slideshow: Every Corvette Grand Sport explained

By Joe Kucinski | 2026-03-26 07:13:44


VIEW MORE
story-8
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!

Slideshow: Breaking down the 2027 Grand Sport, Grand Sport X, Stingray, and LS6 V8.

By Michael S. Palmer | 2026-03-26 13:48:45


VIEW MORE
story-9
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!

Slideshow: 5 reasons bad drivers crash sports cars & 5 ways to avoid a costly shame!

By Joe Kucinski | 2026-03-25 16:32:55


VIEW MORE