stock block compression/ head ?

Reply Subscribe

Thread Tools

Search this Thread

Jul 7, 2010 | 11:55 PM

SPRAYED Z

Thread Starter

TECH Apprentice

iTrader: (4)

Joined: Jul 2009

Posts: 360

Likes: 0

stock block compression/ head ?

Whats the stock chamber volume on bone stock lt1 untouched heads, engine? Im wondering what it would be once I change heads and gaskets. thanks

Jul 8, 2010 | 12:02 AM

RamAir95TA

TECH Senior Member

iTrader: (2)

Joined: May 2005

Posts: 9,467

Likes: 8

From: South Jersey

Stock heads are 58cc from what I recall.

Gasket thickness does not determine head CC size. The only way to have the head CC measured is to have them CC'd.

Jul 8, 2010 | 12:03 AM

RamAir95TA

TECH Senior Member

iTrader: (2)

Joined: May 2005

Posts: 9,467

Likes: 8

From: South Jersey

Stock heads are 58cc from what I recall.

Gasket thickness does not determine head CC size. The only way to have the head CC measured is to have them CC'd.

Jul 8, 2010 | 12:05 AM

SPRAYED Z

Thread Starter

TECH Apprentice

iTrader: (4)

Joined: Jul 2009

Posts: 360

Likes: 0

ok thanks and what about the pistons, what type of valve reliefs are they 5cc or what?

ALso do you know the deck height of a stock block and far in the hole the pistons are?

im trying to input numbers in to find out my compression and i want to make sure of them.

its a stock block with 57cc heads that were milled and a .026 gasket. Do you know what it might be?

Jul 8, 2010 | 12:08 AM

RamAir95TA

TECH Senior Member

iTrader: (2)

Joined: May 2005

Posts: 9,467

Likes: 8

From: South Jersey

Quote:

Originally Posted by SPRAYED Z

ok thanks and what about the pistons, what type of valve reliefs are they 5cc or what?

ALso do you know the deck height of a stock block and far in the hole the pistons are?

Stock piston volume has -5cc reliefs. Piston depth on a stock block is around .015" to .020". I've seen some as deep as .030" though.

Jul 8, 2010 | 12:54 AM

SPRAYED Z

Thread Starter

TECH Apprentice

iTrader: (4)

Joined: Jul 2009

Posts: 360

Likes: 0

well using a .026 gasket and deck height of .020 I get a 10.8 compression. That seem correct?

Jul 8, 2010 | 02:52 AM

suicidal racing

TECH Fanatic

iTrader: (14)

Joined: Sep 2007

Posts: 1,074

Likes: 8

From: Mass

i know with my .15 gasket an 58cc heads with stock deck im around 11.4-1 comp..

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

Verdad Gallardo

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Pouria Savadkouei

Top 10 Most Powerful Chevy Trucks Ever Made!

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Verdad Gallardo

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

Verdad Gallardo

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Verdad Gallardo

10 Camaros You Should Never Buy

10 LS Engine Myths That Refuse to Die

Verdad Gallardo

Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0

Brett Foote

10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever

Verdad Gallardo

Jul 8, 2010 | 01:21 PM

speed_demon24

11 Second Club

iTrader: (6)

Joined: Dec 2001

Posts: 4,609

Likes: 2

From: Ocala, FL

Stock heads are ~54cc FWIW not 58.

Jul 8, 2010 | 05:04 PM

#10

suicidal racing

TECH Fanatic

iTrader: (14)

Joined: Sep 2007

Posts: 1,074

Likes: 8

From: Mass

^there 58cc every spec site online about lt1s and lt1 flow nums say 58cc and my 93-92 camaro book says 58cc in the lt1 section also if i remember right

Jul 8, 2010 | 06:51 PM

#11

Purple Poncho

TECH Apprentice

iTrader: (1)

Joined: Apr 2004

Posts: 397

Likes: 6

I have always heard 54cc.

Jul 8, 2010 | 08:48 PM

#12

wrd1972

TECH Veteran

iTrader: (12)

Joined: Mar 2006

Posts: 4,668

Likes: 5

From: Central Kentucky

I say 54cc too.

Jul 8, 2010 | 09:21 PM

#13

Spiers

TECH Enthusiast

iTrader: (7)

Joined: Jun 2007

Posts: 739

Likes: 0

From: St Joseph, MO

If I'm not mistaken, the LT1 heads are 58cc, and the LT4 heads are 54cc.

Jul 8, 2010 | 09:52 PM

#14

Speedy

TECH Enthusiast

Joined: Jun 2002

Posts: 634

Likes: 0

From: In the garage fixing LT1

Mine cc'd at 55. The numbers seem to vary everywhere you look. They are definitely not 58cc.

Jul 8, 2010 | 09:57 PM

#15

Spiers

TECH Enthusiast

iTrader: (7)

Joined: Jun 2007

Posts: 739

Likes: 0

From: St Joseph, MO

What I stated above is what it reads in the book "How to Rebuild Small-Block Chevy LT1/LT4 Engines."

Jul 8, 2010 | 10:07 PM

#16

robsquikz28

TECH Veteran

iTrader: (246)

Joined: Mar 2008

Posts: 4,984

Likes: 1

From: Chicago/Crown point

I remember seeing them at 54cc and lt4 at 54.4cc But I asked Lloyd once about 2 years ago and he told me 58

Jul 9, 2010 | 08:52 PM

#17

Speedy

TECH Enthusiast

Joined: Jun 2002

Posts: 634

Likes: 0

From: In the garage fixing LT1

Quote:

Originally Posted by Spiers

What I stated above is what it reads in the book "How to Rebuild Small-Block Chevy LT1/LT4 Engines."

Look on page 14 of that book under specifications. LT1 54.4cc chambers and 170cc intake port volume. LT4 54.4cc chambers with 185cc intake port volume.

I have had a shop tell me I had 58cc heads. I had to show him the stats to change his mind. He insisted on cc'ing the heads, refused to believe the documentation. 56-55cc is what we got on 1993 LT1 heads. It seems to vary from head to head, possibly from year to year. I don't know where so many are getting 58cc. Possibly the #s changed from year to year? Does it possibly have to do with the valves?

I would like to know where the 58cc number is coming from.