GM Engine & Exhaust Performance EFI | GEN I/GEN II/GEN III/GEN IV Engines |Small Block | Big Block |

Check my pushrod math, please

Thread Tools
 
Search this Thread
 
Old 04-28-2012 | 09:28 AM
  #11  
redsilv's Avatar
On The Tree
 
Joined: Feb 2010
Posts: 140
Likes: 0
From: colorado
Default

go buy a comp cam pushrod checker, it has a mark that you count
put the checker in the lifter and tighten the rocker arm to 22ft/lb
rotate that checker until you get zero lash and no movement from the
rocker arm
take the checker out and count the revolutions and add your preload

thats all in a nut shell
but i would bet something is definitely wrong with your pushrods in the video
keep us posted how you fixed it
Old 04-28-2012 | 12:57 PM
  #12  
mcdonald77's Avatar
Thread Starter
Launching!
iTrader: (19)
 
Joined: Jul 2004
Posts: 254
Likes: 0
From: Sedro Woolley, WA
Default

just ordered the comp cams 7702-1. I used the other length checker last time where it has the jam nuts on it. Maybe I will have better luck with this. Right or wrong I am going to check it before I get that first drive in. I have only moved it twice and for a few minutes each time. Once I am sure on the valve train I can go put a load on it to set set the piston rings.
Old 04-28-2012 | 02:07 PM
  #13  
SC2150's Avatar
Teching In
 
Joined: Apr 2012
Posts: 21
Likes: 0
Default

You can also use this method: from zero lash, 1/4-1 turn of the pedestal bolt should put you within the .040-.080 spec. (1/4 turn is on the loose side and would be minimum preload). Or do it like most shops and guess and then tell the customer "that sewing machine noise is normal"......NOT! :thumbsup:
Old 04-28-2012 | 09:27 PM
  #14  
redsilv's Avatar
On The Tree
 
Joined: Feb 2010
Posts: 140
Likes: 0
From: colorado
Default

i used the comp cams checker and still checked every
dang valve on the engine at least 1400000 times !! lol

but i gues i got it right because there is no lifter noise at all
in my engine. i got the hi tech pushrods and my 15 yr old
put them in and torqued the rockers at 22 ft/lbs. we also used
blue loctite just for my peace of mind

the comp cams valve spring compressor was cake too !
Old 04-29-2012 | 10:36 PM
  #15  
mcdonald77's Avatar
Thread Starter
Launching!
iTrader: (19)
 
Joined: Jul 2004
Posts: 254
Likes: 0
From: Sedro Woolley, WA
Default

thanks for the responses!
Old 05-02-2012 | 04:42 PM
  #16  
mcdonald77's Avatar
Thread Starter
Launching!
iTrader: (19)
 
Joined: Jul 2004
Posts: 254
Likes: 0
From: Sedro Woolley, WA
Default

Ok,

I got my comp cam tool today. check 2 cylinders. I made sure I was at tcd on the compression stroke using a straw in the spark plug hole and watching the valve springs while turning it over. Both intake and exhaust I got 9.24 turns down to 6.8, If my math is correct

6.8 smallest length of checker tool
9.25 x .050 = .4625

.4625 + 6.8 = 7.2625

7.2625 + .080 = 7.3425

I used 7.350 pushrods.


1.25 turns from 0 lash to 22 foot pounds

Last edited by mcdonald77; 05-02-2012 at 05:04 PM.
Old 05-02-2012 | 06:58 PM
  #17  
Atomic's Avatar
I have a gauge for that
iTrader: (42)
 
Joined: Jan 2006
Posts: 16,266
Likes: 394
From: Huntsville, AL
Default

If you are using a length checker, you need to tighten the rocker down, then adjust the tool until you get zero lash. Then add the length of the tool to the preload you want.
Old 05-02-2012 | 07:04 PM
  #18  
mcdonald77's Avatar
Thread Starter
Launching!
iTrader: (19)
 
Joined: Jul 2004
Posts: 254
Likes: 0
From: Sedro Woolley, WA
Default

Ive actually done it both ways, snug and torqued. I am thinking I am right around ball park. I will take some more inside video In a little while.
Old 05-02-2012 | 08:39 PM
  #19  
mcdonald77's Avatar
Thread Starter
Launching!
iTrader: (19)
 
Joined: Jul 2004
Posts: 254
Likes: 0
From: Sedro Woolley, WA
Default

I was going on the maiden voyage, but my wideband decided to black out on me. Anyone have an NGK AFX stop displaying?
Old 05-02-2012 | 08:48 PM
  #20  
Atomic's Avatar
I have a gauge for that
iTrader: (42)
 
Joined: Jan 2006
Posts: 16,266
Likes: 394
From: Huntsville, AL
Default

Yes, actually. Disconnect the power wire, wait a few seconds, and plug it back up.



All times are GMT -5. The time now is 09:40 AM.