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

Main caps question

Thread Tools
 
Search this Thread
 
Old Sep 19, 2009 | 04:17 AM
  #1  
Sliding's Avatar
Sliding
Thread Starter
Drifting
15 Year Member
 
Joined: Jun 2001
Posts: 1,625
Likes: 1
From: Zagreb, Croatia
Default Main caps question

I've acquired a second block for my engine (since my original block can't be repaired). Problem is that this block wasn't assembled when I got it and now I don't know main caps positions.

Is there any way to identify main caps position?
If I switch their positions, is align honing a must?
Reply
Old Sep 19, 2009 | 10:05 AM
  #2  
rklessdriver's Avatar
rklessdriver
Safety Car
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 2005
Posts: 3,624
Likes: 431
From: Dale City VA
Default

GM stamp numbers the main caps. The stamp is located right on top (right side).

Sometimes the stamps are light and hard to read but they are there.

The rear cap is not numbered but it's position should be evident (its completely different so the oil pump will bolt up).
Will
Reply
Old Sep 19, 2009 | 12:20 PM
  #3  
Sliding's Avatar
Sliding
Thread Starter
Drifting
15 Year Member
 
Joined: Jun 2001
Posts: 1,625
Likes: 1
From: Zagreb, Croatia
Default

After a little closer examination, I think that I've located numbers 2, 3 and 4 and that's enough.

Other question is, if I put a crank that was in different engine into this
block, does it also require align honing or some other machining?
Reply
Old Sep 20, 2009 | 12:05 PM
  #4  
M. Schumacher's Avatar
M. Schumacher
Pro
 
Joined: Jun 2008
Posts: 610
Likes: 1
Default

You don't need to fool with the block for a crank change. However, unless you are certain about the pedigree of the new block and caps then it's good insurance to have it done anyway. In fact, even if you do know for certain that you have the caps that go to that block, there could be core shift throwing the journals out of line. Is it worth the $150 or so to make sure?
Reply
Old Sep 20, 2009 | 12:14 PM
  #5  
JackDidley's Avatar
JackDidley
Race Director
20 Year Member
Active Streak: 30 Days
Liked
Loved
 
Joined: Sep 2003
Posts: 16,836
Likes: 337
From: Database Error Indiana
Default

Put in the bearings and crank and torque it down. If the bearing clearance is good and it spins free, its good.
Reply
Old Sep 20, 2009 | 10:06 PM
  #6  
CFI-EFI's Avatar
CFI-EFI
Race Director
10 Year Member
 
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Default


How could core shift, which occurs before the block is out of the mold, survive the final factory machining? A crank shaft change could never cause a need for align boring or honing. The main bearing bores can be checked for alignment and corrected if necessary without preforming the operation.

RACE ON!!!
Reply
Old Sep 20, 2009 | 10:48 PM
  #7  
M. Schumacher's Avatar
M. Schumacher
Pro
 
Joined: Jun 2008
Posts: 610
Likes: 1
Default

Perhaps "core shift" wasn't the proper nomenclature. Engine blocks are known to "adjust" to some extent after undergoing normal heat cycles. That is why engine builders often prefer to choose used blocks for performance builds. Considering the time and money involved in doing such a job, I would prefer to know that everything is correct.
Reply
Old Sep 20, 2009 | 11:03 PM
  #8  
Muffin's Avatar
Muffin
Race Director
Supporting Lifetime Gold
10 Year Member
 
Joined: Jun 1999
Posts: 14,924
Likes: 9
From: Merritt Ils Fl
Default

Originally Posted by JackDidley
Put in the bearings and crank and torque it down. If the bearing clearance is good and it spins free, its good.
Align hone is obviously the best but if it passes this test you should be safe.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-1

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-2

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
story-3

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-4

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-5

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-6

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-7

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-8

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

 Michael S. Palmer
story-9

2027 Corvette vs The World: Every C8 vs Its Closest Competitor

 Joe Kucinski
Old Sep 21, 2009 | 12:24 AM
  #9  
CFI-EFI's Avatar
CFI-EFI
Race Director
10 Year Member
 
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Default

Originally Posted by M. Schumacher
Considering the time and money involved in doing such a job, I would prefer to know that everything is correct.
I agree, it is important "to know that everything is correct.". I also agree that dimensions can change through age and repeated heat cycles. However, it isn't necessary to re-bore or hone the main bearing bores in the block Just "to know that everything is correct." and to ensure the alignment is correct. When you check your tire pressure, do you first purge all the air, dismount and remount the tire "to know that everything is correct."? Just because you throw money at something doesn't guarantee it is correct. Have you ever heard of operator error, or "don't fix what ain't broke"?

RACE ON!!!
Reply

Get notified of new replies

To Main caps question





All times are GMT -4. The time now is 08:22 AM.

story-0
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-1
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-2
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
story-3
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-4
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-5
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-6
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-7
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-8
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-9
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE