Pushrod Length Guidance

Thread Tools
 
Search this Thread
 
Old Mar 4, 2016 | 02:28 AM
  #1  
AK71CutlassS's Avatar
Thread Starter
Registered User
 
Joined: May 2014
Posts: 152
Pushrod Length Guidance

So I bought a pushrod checking tool and I'm trying to figure out the correct pushrod length. Is there a way to do it without collapsing the hydraulic roller lifter? My heads are installed.
My steps I've been doing are as follows
- set the lifter on the base of cam lob
- Mark top of stem with marker
-set pushrod checker to zero lash and then a half turn more
- rotate engine 2 full revolutions
- then see where the mark is on valve stem and adjust accordingly
- is this correct? My initial measurement was 9.05 with the line in the middle of stem
I just did one valve so far ..being that I'm unsure

Thanks in advance

Tony

Last edited by AK71CutlassS; Mar 5, 2016 at 02:12 AM.
Old Mar 6, 2016 | 03:22 AM
  #2  
AK71CutlassS's Avatar
Thread Starter
Registered User
 
Joined: May 2014
Posts: 152
well just finished my work week. Any info would be much appreciated
Old Mar 6, 2016 | 08:30 AM
  #3  
midrange's Avatar
Shaking out the cobwebs..
 
Joined: May 2011
Posts: 234
From: Marysville, Michigan
Everything sounds good.
I don't know that you need the extra half turn though when setting the zero lash to check length.
Old Mar 7, 2016 | 02:49 AM
  #4  
AK71CutlassS's Avatar
Thread Starter
Registered User
 
Joined: May 2014
Posts: 152
Yeah like EFI said. I believe my lifter springs are collapsing a bit when I rotate engine. I have heads installed already so I'm wondering how I can get a solid lifter the same length as my erson hydraulic roller lifters... Ugh this is difficult
Old Mar 7, 2016 | 06:42 AM
  #5  
83hurstguy's Avatar
Registered User
 
Joined: Jun 2008
Posts: 1,434
From: Chicago
last time I did this with a hydraulic flat tappet, I had two lifters that I disassembled, filled with epoxy, and reassembled so they couldn't collapse. Little more expensive to do with roller lifters.

Your process sounds good. Just remember that you aren't necessarily concerned with having the witness line on the valve tip be perfectly centered, but you want the least transverse "travel" across the valve tip possible to eliminate side loading (shown by the narrowest witness mark you can achieve). This is determined by having the rocker perpendicular to the valve at 50% lift.
Old Mar 8, 2016 | 06:50 PM
  #6  
gbledsoe3's Avatar
Registered User
 
Joined: Oct 2012
Posts: 140
I read this recently in BTR's book on measuring push rod length for hydraulic lifters:

"Using an adjustable pushrod to fill in the distance between rocker and lifter, add about .050 for hydraulic-lifter applications to give proper preload."

I can not attest to the validity of that statement, I'm only sharing what I read.
Old Mar 8, 2016 | 07:15 PM
  #7  
coppercutlass's Avatar
Chevy budget Olds powered
 
Joined: Jul 2011
Posts: 8,638
From: Elgin, Illinois
If you are talking about when checking for proper length you are compressing the lifter plunger you can can buy a set of checking springs . they are like 15 bucks and are the way to go.
Old Mar 8, 2016 | 11:03 PM
  #8  
AK71CutlassS's Avatar
Thread Starter
Registered User
 
Joined: May 2014
Posts: 152
That's the problem I really don't wanna take the heads back off
Old Mar 8, 2016 | 11:05 PM
  #9  
coppercutlass's Avatar
Chevy budget Olds powered
 
Joined: Jul 2011
Posts: 8,638
From: Elgin, Illinois
You can change the springs with the heads on the engine. There is a tool for it and a procedure.
Old Mar 8, 2016 | 11:21 PM
  #10  
AK71CutlassS's Avatar
Thread Starter
Registered User
 
Joined: May 2014
Posts: 152
Yeah. hmm this is really frustrating.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
dsolomon
Small Blocks
9
Jul 4, 2020 05:20 PM
joepenoso
Big Blocks
3
Feb 5, 2013 09:45 AM
russell-t
Small Blocks
6
Oct 8, 2012 05:58 AM
russell-t
Small Blocks
0
Nov 4, 2011 09:17 PM
Warhead
Small Blocks
2
May 31, 2011 01:24 PM




All times are GMT -7. The time now is 07:51 AM.