CorvetteForum - Chevrolet Corvette Forum Discussion

C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

Calculating compression ratio

   
Old Mar 13, 2011 | 12:09 AM
Share
  #1  
Dr L-88's Avatar
Dr L-88
Thread Starter
Le Mans Master
15 Year Member
Liked
Loved
Top Answer: 5
 
Joined: Oct 2007
Posts: 6,007
Likes: 1,746
From: Richmond Kentucky
2025 Corvette of the Year Winner- Modified
2024 C2 of the Year Winner - Modified
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
Default Calculating compression ratio
What compression ratio will this combination yield?

454 block .030 over, stock stroke, std deck height

TRW L2349 piston

Cast iron GM head #336781 open chamber with 113 cc chamber

Fel Pro composition gasket .039 compressed thickness

Thanks,
Rex
Reply
0
Old Mar 13, 2011 | 03:44 AM
Share
  #2  
northern77's Avatar
northern77
Advanced
 
Joined: Jun 2010
Posts: 86
Likes: 0
From: Pulaski Wisconsin
Default
Try this.
http://www.angelfire.com/fl/procrastination/motor.html
Reply
0
Old Mar 13, 2011 | 06:47 AM
Share
  #3  
HamadUP's Avatar
HamadUP
Melting Slicks
Supporting Lifetime
20 Year Member
 
Joined: Jan 2003
Posts: 2,877
Likes: 13
From: Doha
St. Jude Donor '08
Default
I used this calculator (http://www.csgnetwork.com/compcalc.html) and it gave me 10.85.
Reply
0
Old Mar 13, 2011 | 09:28 PM
Share
  #4  
trw's Avatar
trw
Melting Slicks
20 Year Member
 
Joined: May 2000
Posts: 2,125
Likes: 9
From: Crescent City, CA
Default
Are you sure on the 781's at 113?
If running a stock deck, use the steel shim head gaskets.
Hope this helps.
Reply
0
Old Mar 13, 2011 | 10:28 PM
Share
  #5  
Dr L-88's Avatar
Dr L-88
Thread Starter
Le Mans Master
15 Year Member
Liked
Loved
Top Answer: 5
 
Joined: Oct 2007
Posts: 6,007
Likes: 1,746
From: Richmond Kentucky
2025 Corvette of the Year Winner- Modified
2024 C2 of the Year Winner - Modified
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
Default
Originally Posted by trw
Are you sure on the 781's at 113?
If running a stock deck, use the steel shim head gaskets.
Hope this helps.

Both of these sites show 113 cc, I found another site that says 118 cc.

http://www.minuit10.net/EngineCode/c...linderHead.htm

http://www.nastyz28.com/bbcmenu.php
Last edited by Dr L-88; Mar 13, 2011 at 10:31 PM.
Reply
0
Old Mar 14, 2011 | 12:11 AM
Share
  #6  
Steve439's Avatar
Steve439
Le Mans Master
25 Year Member
Conversation Starter
All Eyes On Me
Liked
 
Joined: Oct 2000
Posts: 7,831
Likes: 5
From: Austin TX
Default
With your specs about 10.6, but I agree with trw, the 781s are probaly bigger.

At 118 you'd have around 10.2
Reply
0
Old Mar 14, 2011 | 01:43 PM
Share
  #7  
63mako's Avatar
63mako
Race Director
20 Year Member
Liked
Loved
Community Favorite
 
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Default
CC the heads. Cheap and easy.
Reply
0

Get notified of new replies

To Calculating compression ratio

Tags
Back to Subforum
C3 Tech/Performance
View Next Unread
C3 Transmission Mount Height Question


Thread Tools
Search this Thread
Search this Thread:

Click for Advanced Search

Click for Advanced Search
Reply Closed Thread Share
Forum Jump
Trending Topics

All times are GMT -4. The time now is 04:51 PM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 11:09:53


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE