Generation III Internal Engine 1997-2006 LS1 | LS6
Sponsored by:
Sponsored by:

Check my math...

Thread Tools
 
Search this Thread
 
Old Jan 25, 2006 | 06:46 PM
  #1  
My90Iroc's Avatar
Thread Starter
TECH Enthusiast
iTrader: (26)
 
Joined: Mar 2004
Posts: 589
Likes: 0
From: Long Island
Default Check my math...

Working on pushrod math...

(SCBC) Stock cam base circle: 1.552 dia. (.776) rad.
(CCBC) Comp cam base circle: 1.455 dia. (.7275) rad. I'm using the futral base circle number assuming it's pretty close to the comp until I get my cam and cam card
(SPR) stock pushrod length (actual): 7.380
(APR) aftermarket pushrod length: 7.400 Variable
(SHG) Stock '00 head gasket: .056
(NHG) New head gasktet: .043
(M) Milling: .010

So hear's what I've come up with...
(SCBC-CCBC)-(SHG-NHG)-M-(APR-SPR) = plunger height difference from stock
(.776-.7275)-(.056-.043)-.010-(7.400-7.380) = .0055

Assuming my base circle number is right then using 7.400" pushrods would only make my lifter plunger .0055" higher than stock. Am I missing anything here?
Reply
Old Jan 25, 2006 | 07:59 PM
  #2  
redtail2426's Avatar
TECH Fanatic
iTrader: (10)
 
Joined: Aug 2004
Posts: 1,433
Likes: 0
From: Rochester,Ny
Default

everything looks good except that stock pushrods are more like 7.395.'' I measured stock pushrods from two different f-body ls1's,with 3 different tools and came up with an average of 7.395.the shortest was 7.391 and the longest was 7.398.i dont know where the 7.380 originated from but its incorrect.
Reply
Old Jan 25, 2006 | 08:43 PM
  #3  
My90Iroc's Avatar
Thread Starter
TECH Enthusiast
iTrader: (26)
 
Joined: Mar 2004
Posts: 589
Likes: 0
From: Long Island
Default

Originally Posted by redtail2426
everything looks good except that stock pushrods are more like 7.395.'' I measured stock pushrods from two different f-body ls1's,with 3 different tools and came up with an average of 7.395.the shortest was 7.391 and the longest was 7.398.i dont know where the 7.380 originated from but its incorrect.
Ok, so then using 7.395 as stock that would put the plunger .0205 higher than stock.
(.776-.7275)-(.056-.043)-.010-(7.400-7.395) = .0205

That should work because I was told that the tolerance for the lifter plunger is about .020

Again, this is all assuming the base circle of a Comp Cam is 1.455" Can anyone verify this? The cam is 232/234 .595"/.598"
Reply
Old Jan 26, 2006 | 08:57 AM
  #4  
GuitsBoy's Avatar
TECH Senior Member
iTrader: (4)
 
Joined: Apr 2003
Posts: 6,249
Likes: 3
From: Long Island, NY
Default

He probably got the 7.380 number from me. Its the number ive seen tossed around the forum quite a bit. It may even be in one of the stickies. Not to mention that its the default number in the pushrod calculator sheet

Since the search is broken, i used google and viewed this cached page:
http://72.14.203.104/search?q=cache:...ient=firefox-a

Ill take a caliper to one of the stock PRs I took out of my car and decide for myself.

Last edited by GuitsBoy; Jan 26, 2006 at 09:08 AM.
Reply
Old Jan 26, 2006 | 09:14 AM
  #5  
white2001s10's Avatar
TECH Fanatic
iTrader: (4)
 
Joined: May 2002
Posts: 1,851
Likes: 0
From: Fairview Heights Illinois
Default

The math is good, but there's only one real way to find out exactly what you need. Things like just a valvejob can change the numbers.
Are the heads untouched?
I ask because you list milling and new gaskets.
Reply
Old Jan 26, 2006 | 09:19 AM
  #6  
GuitsBoy's Avatar
TECH Senior Member
iTrader: (4)
 
Joined: Apr 2003
Posts: 6,249
Likes: 3
From: Long Island, NY
Default

Originally Posted by white2001s10
Are the heads untouched? I ask because you list milling and new gaskets.
Theyre absolute speed 5.3 heads with bigger valves, so theres a good chance the valves may not seat at the stock height.
Reply
Old Jan 26, 2006 | 09:26 AM
  #7  
white2001s10's Avatar
TECH Fanatic
iTrader: (4)
 
Joined: May 2002
Posts: 1,851
Likes: 0
From: Fairview Heights Illinois
Default

You should go across the fence and help him mock it up so it'll be right.
You could do math all day and still be off.
Reply
Old Jan 26, 2006 | 09:37 AM
  #8  
GuitsBoy's Avatar
TECH Senior Member
iTrader: (4)
 
Joined: Apr 2003
Posts: 6,249
Likes: 3
From: Long Island, NY
Default

Originally Posted by white2001s10
You should go across the fence and help him mock it up so it'll be right.
You could do math all day and still be off.
Ill definately be lending a helping hand. Ive actually had these heads in hand briefly while I was helping him clean them up. I forgot to take some measurements vs. a stock ls1 head. Ill do so before we mill them, hopefully this weekend.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

 Brett Foote
story-1

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-2

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-3

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-4

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-5

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-6

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

 Verdad Gallardo
story-7

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-8

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-9

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
Old Jan 28, 2006 | 08:55 PM
  #9  
My90Iroc's Avatar
Thread Starter
TECH Enthusiast
iTrader: (26)
 
Joined: Mar 2004
Posts: 589
Likes: 0
From: Long Island
Default

Update...

Today we mocked up the head, rocker, and push rod then took some measurements. It appears the valves in my AS 5.3's sit .050" higher (basically canceling out the difference in base circles) than the stock setup. We also measured a stock push rod and a comp 7.4" and found the stock to be 7.398 and comp 7.411. So here's my new formula..

(.776-.7275)-(.056-.043)-.010-(7.411-7.398)-.050 = .0375
(.776-.7275)-(.056-.043)-.010-(7.375-7.398)-.050 = .0005

So the comp or SLP 7.375" PR's look like the best fit. I know most people just throw in 7.4's or 7.35's and I'm not sure if that's due to cost, proven setup, or if my setup is that unique (which I really doubt). But with all the different setups out there I'm surprised the stock lifters have enough tolerance to accomodate all the different setups let alone the .050" difference in the popular PR's I just listed. Anyways I thougtht these results would be interesting to share. My wheels have been turning while I'm sitting here waiting for all my parts to arrive.
Reply




All times are GMT -5. The time now is 08:55 AM.

story-0
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-09 14:55:56


VIEW MORE
story-1
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-2
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-3
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-4
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-5
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-6
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-7
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-8
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-9
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE