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

7.235 PR length???

Thread Tools
 
Search this Thread
 
Old Jan 15, 2007 | 03:10 PM
  #1  
pdd's Avatar
pdd
Thread Starter
TECH Veteran
iTrader: (3)
 
Joined: Aug 2003
Posts: 4,156
Likes: 0
From: dudley mass
Default 7.235 PR length???

so i measured the PR on the heel of the cam. snugged down the rockers. twisted the PR length checker. got out my digital calipers and measured. i come up with 7.235. does that sound right?? then if i add the .060 preload for the cadillac lifters i get 7.295

Last edited by pdd; Jan 15, 2007 at 03:29 PM.
Reply
Old Jan 15, 2007 | 03:33 PM
  #2  
Patrick G's Avatar
LS1 Tech Administrator
20 Year Member
Photogenic
iTrader: (14)
 
Joined: Nov 2001
Posts: 8,246
Likes: 34
From: Victoria, TX
Default

If you're running an XE-R cam, you typically need to run a .050" longer pushrod than stock to maintain the .100" factory plunger depth. Milled heads, thinner gaskets and different lifters will change this.

With your combination:
.030" mill
.040" gaskets
.060" plunger depth

A 7.350" pushrod is the closest thing that will give you the .060" plunger depth.
__________________

2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.

Reply
Old Jan 15, 2007 | 05:12 PM
  #3  
pdd's Avatar
pdd
Thread Starter
TECH Veteran
iTrader: (3)
 
Joined: Aug 2003
Posts: 4,156
Likes: 0
From: dudley mass
Default

why the heck am i so far off?
Reply
Old Jan 15, 2007 | 05:18 PM
  #4  
Patrick G's Avatar
LS1 Tech Administrator
20 Year Member
Photogenic
iTrader: (14)
 
Joined: Nov 2001
Posts: 8,246
Likes: 34
From: Victoria, TX
Default

Originally Posted by pdd
why the heck am i so far off?
It seems like everyone that uses a pushrod checker winds up coming up with a pushrod that's too short. Don't think that the Cadillac lifter is any taller than stock...
__________________

2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.

Reply
Old Jan 15, 2007 | 05:21 PM
  #5  
pdd's Avatar
pdd
Thread Starter
TECH Veteran
iTrader: (3)
 
Joined: Aug 2003
Posts: 4,156
Likes: 0
From: dudley mass
Default

Originally Posted by Patrick G
Don't think that the Cadillac lifter is any taller than stock...
its the same length as stock, it just uses a .060 preload
Reply
Old Jan 15, 2007 | 05:24 PM
  #6  
Tony Mamo @ AFR's Avatar
Flow Wizard
20 Year Member
iTrader: (13)
 
Joined: Feb 2004
Posts: 2,197
Likes: 7
Default

Originally Posted by pdd
why the heck am i so far off?
Pat...

Open the checking pushrod to the length you came up with by adding .060 and then see how many turns of the factory rocker bolt from the basecircle to fully tightened (representing the pushrod preload). If your measurments are right I bet you will be a little over one full turn from zero lash to fully tightened. If thats the case you are good to go although I would run a little more preload (closer to .100 which is a little less than two full turns) for an even quieter valvetrain). Make sure you are on the heel of the cam (basecircle) on the cylinder you are checking...

Tony M.

PS...What rockers are you running?....stock??
Reply
Old Jan 15, 2007 | 05:34 PM
  #7  
vettenuts's Avatar
TECH Senior Member
iTrader: (4)
 
Joined: Jul 2004
Posts: 8,092
Likes: 13
From: Little Rhody
Default

How are you measuring the length of the adjustable? You need to use the indicator on the side (two opposing white lines), with each turn equal to 0.050" longer in pushrod length. If you are using the Comp pushrod with the 6.800" base length, then 10 turns would be 7.300" pushrod length. Note also that the pushrod measurement is done in gauge length, not what you measure with a tool like a vernier.
Reply
Old Jan 15, 2007 | 05:42 PM
  #8  
pdd's Avatar
pdd
Thread Starter
TECH Veteran
iTrader: (3)
 
Joined: Aug 2003
Posts: 4,156
Likes: 0
From: dudley mass
Default

Originally Posted by Tony Mamo @ AFR
Tony M.

PS...What rockers are you running?....stock??

rebuilt stockers
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

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

 Verdad Gallardo
story-1

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

 Pouria Savadkouei
story-2

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

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

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

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Jan 15, 2007 | 05:45 PM
  #9  
pdd's Avatar
pdd
Thread Starter
TECH Veteran
iTrader: (3)
 
Joined: Aug 2003
Posts: 4,156
Likes: 0
From: dudley mass
Default

Originally Posted by vettenuts
How are you measuring the length of the adjustable? You need to use the indicator on the side (two opposing white lines), with each turn equal to 0.050" longer in pushrod length. If you are using the Comp pushrod with the 6.800" base length, then 10 turns would be 7.300" pushrod length. Note also that the pushrod measurement is done in gauge length, not what you measure with a tool like a vernier.
im using the comp adjustable PR lengh checker
Reply
Old Jan 15, 2007 | 06:10 PM
  #10  
jetblast's Avatar
Launching!
 
Joined: Dec 2005
Posts: 232
Likes: 0
From: nj, edison
Default

Originally Posted by Tony Mamo @ AFR
Pat...

Open the checking pushrod to the length you came up with by adding .060 and then see how many turns of the factory rocker bolt from the basecircle to fully tightened (representing the pushrod preload). If your measurments are right I bet you will be a little over one full turn from zero lash to fully tightened. If thats the case you are good to go although I would run a little more preload (closer to .100 which is a little less than two full turns) for an even quieter valvetrain). Make sure you are on the heel of the cam (basecircle) on the cylinder you are checking...

Tony M.

PS...What rockers are you running?....stock??
that's the method i used to come up with .350 push rd. my preload was 1.75 turns, now is 1.25 turns and my valvtrain is much quieter.
Reply
Old Jan 15, 2007 | 07:22 PM
  #11  
Tony Mamo @ AFR's Avatar
Flow Wizard
20 Year Member
iTrader: (13)
 
Joined: Feb 2004
Posts: 2,197
Likes: 7
Default

Originally Posted by jetblast
that's the method i used to come up with .350 push rd. my preload was 1.75 turns, now is 1.25 turns and my valvtrain is much quieter.
Its quieter with less preload (1.25 turns)?? I have usually seen just the opposite but anything is possible.

Tony

PDD....Gotcha on the rebuilt stock rockers....they should work fine.
Reply




All times are GMT -5. The time now is 06:59 PM.

story-0
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-1
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-2
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-3
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-4
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-5
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
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE