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

Could you please help me with pushrod length

Thread Tools
 
Search this Thread
 
Old Jan 20, 2013 | 09:10 PM
  #1  
SSmikeSS's Avatar
Thread Starter
Launching!
iTrader: (2)
 
Joined: Mar 2006
Posts: 217
Likes: 0
Default Could you please help me with pushrod length

I posted this on Performance.net but I'd like you all to please look at this for me.
It's the same heads and cam I used on my 6.0. (in my sig) I'm installing on my new 408 from Texas Speed.
I bought the pushrod length checker tool. I checked 4 different spots and made sure I was on the base of the cam. I came up with 8 turns with the length checker all four times.
8x .050= .4 +6.8= 7.2 + preload. That's a pretty short pushrod. Any idea what I'm doing wrong??? Or do I really need that short or a PR.
I've been running 7.4" for years. I never used the length checker before and this is what I'm coming up with.

Today I tried the 7.4" and saw that the valve was opening more than when I used the checker tool opened to 7.275" .
What do you think?

Thanks,
Mike
Reply
Old Jan 21, 2013 | 04:02 PM
  #2  
LS1MCSS's Avatar
TECH Junkie
iTrader: (18)
 
Joined: Jan 2006
Posts: 3,831
Likes: 8
From: Dover, Arkansas
Default

You have the rocker stands on there?
Reply
Old Jan 21, 2013 | 04:26 PM
  #3  
badazz81z28's Avatar
TECH Addict
15 Year Member
iTrader: (6)
 
Joined: Sep 2005
Posts: 2,391
Likes: 3
Default

That seems way short. Are you using solid lifters to check?
Reply
Old Jan 21, 2013 | 05:19 PM
  #4  
hiltsy855's Avatar
TECH Fanatic
15 Year Member
Liked
Loved
Community Favorite
iTrader: (35)
 
Joined: Jun 2007
Posts: 1,148
Likes: 28
From: Iowa
Default

Sounds about right if you are using Morel / Lunati lifters....
Reply
Old Jan 22, 2013 | 01:05 PM
  #5  
SSmikeSS's Avatar
Thread Starter
Launching!
iTrader: (2)
 
Joined: Mar 2006
Posts: 217
Likes: 0
Default

Originally Posted by LS1MCSS
You have the rocker stands on there?
LOL I did forget the first time around. I only got 4 turns on the length checker. But I did install the stands to come up with these measurements.

I'm using stock rockers and ls7 lifters.

I think I understand your comment about using solid lifters to check though.

If I'm measuring on the base of the cam there should be no question Right??

PARANOIA lol I really want to get this right
Thanks for your help.
Reply
Old Jan 22, 2013 | 01:27 PM
  #6  
Ferocity02's Avatar
TECH Senior Member
iTrader: (60)
 
Joined: Apr 2003
Posts: 9,397
Likes: 4
Default

Originally Posted by SSmikeSS
LOL I did forget the first time around. I only got 4 turns on the length checker. But I did install the stands to come up with these measurements.

I'm using stock rockers and ls7 lifters.

I think I understand your comment about using solid lifters to check though.

If I'm measuring on the base of the cam there should be no question Right??

PARANOIA lol I really want to get this right
Thanks for your help.
A solid lifter won't help. If the lifter was compressing it would show that you needed a longer pushrod than normal. It's pretty hard to compress a lifter by hand unless it has had spring pressure on it forcing out all of the oil.

Were the heads milled? Block decked? With 0.075" preload yours are only about 0.05" shorter than mine.

Also measure the lenght of the checker to verify. Or just turn it out to 7.4" and see if it matches your other pushrods.
Reply
Old Jan 23, 2013 | 03:54 AM
  #7  
vettenuts's Avatar
TECH Senior Member
iTrader: (4)
 
Joined: Jul 2004
Posts: 8,092
Likes: 13
From: Little Rhody
Default

What brand adjustable pushrod do you have? There are different ones that have different starting lengths.

Did you check the wipe on the rockers prior to taking the measurement? If the valve tips are up (or the valves sunk like some of the TSP heads), then the pushrod will appear to be shorter because the rocker geometry is off. You need to verify the rocker geometry prior to taking any measurements.
Reply
Old Jan 23, 2013 | 01:06 PM
  #8  
SSmikeSS's Avatar
Thread Starter
Launching!
iTrader: (2)
 
Joined: Mar 2006
Posts: 217
Likes: 0
Default

Originally Posted by Ferocity02
A solid lifter won't help. If the lifter was compressing it would show that you needed a longer pushrod than normal. It's pretty hard to compress a lifter by hand unless it has had spring pressure on it forcing out all of the oil.

Were the heads milled? Block decked? With 0.075" preload yours are only about 0.05" shorter than mine.

Also measure the lenght of the checker to verify. Or just turn it out to 7.4" and see if it matches your other pushrods.
The heads were milled when I got them to achieve the stock compression (10.1:1) I figured that would just make them the same height as the the stock 317's.
I will compare the checker with the 7.4". That's a good Idea.
If everything measures the same when I get to work on it this weekend, I am probably buying 7.275ish PR's. That's the middle of the suggested preload.

Originally Posted by vettenuts
What brand adjustable pushrod do you have? There are different ones that have different starting lengths.

Did you check the wipe on the rockers prior to taking the measurement? If the valve tips are up (or the valves sunk like some of the TSP heads), then the pushrod will appear to be shorter because the rocker geometry is off. You need to verify the rocker geometry prior to taking any measurements.
It's the comp tool. It is 6.8".
What do you mean by "wipe" on the rockers?

Thanks for your help.
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 23, 2013 | 04:33 PM
  #9  
gMAG's Avatar
TECH Junkie
20 Year Member
iTrader: (1)
 
Joined: Mar 2003
Posts: 3,033
Likes: 4
From: CT
Default

Originally Posted by SSmikeSS
What do you mean by "wipe" on the rockers?
When the rocker rolls across the valve tip, the rocker forms a 'wipe' pattern.
Ideally, the wipe pattern should be centered across the valvetip.
Reply
Old Jan 24, 2013 | 03:41 AM
  #10  
vettenuts's Avatar
TECH Senior Member
iTrader: (4)
 
Joined: Jul 2004
Posts: 8,092
Likes: 13
From: Little Rhody
Default

Originally Posted by gMAG
When the rocker rolls across the valve tip, the rocker forms a 'wipe' pattern.
Ideally, the wipe pattern should be centered across the valvetip.
This should be checked prior to measuring for pushrods. If the wipe is off, you need to correct the geometry. I am thinking the shorter pushrods might be the result of the valve stem height, and if they are higher than stock the rockers will wipe towards the intake side of the valve stem and need to be raised.

You can't check the wipe with hydraulic lifters and rolling the motor over, you need a set of check springs (they are cheap).
Reply




All times are GMT -5. The time now is 11:49 AM.

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