How many bolt turns to reach .010-.020 lifter preload???
#1
How many bolt turns to reach .010-.020 lifter preload???
I have the Comp R lifters and need to know how many bolt turns its supposed to take to reach the right preload. I did a search and found the 1 turn before it seats, then to 22 ft. lbs. Is this correct??? I have 7.4 pushrods, non milled heads (I believe), and LGs G5X2 cam.
I keep reading the search topics and confusing myself I guess its because Im sick
I keep reading the search topics and confusing myself I guess its because Im sick
#6
8 Second Club
iTrader: (16)
Re: How many bolt turns to reach .010-.020 lifter preload???
turn until there is no valve lash.....then just another 1/4 turn.... must be at top dead center of each valve to set correctly...do one at a time...make sure you are centered or you will not get proper install.
#7
Re: How many bolt turns to reach .010-.020 lifter preload???
turn until there is no valve lash.....then just another 1/4 turn.... must be at top dead center of each valve to set correctly...do one at a time...make sure you are centered or you will not get proper install.
You can use 0 lash but it will sound like a sewing maching. Ive been told that .010-.020 is perfect.
Trending Topics
#8
TECH Junkie
Join Date: Nov 2001
Location: Los Angeles
Posts: 3,604
Likes: 0
Received 0 Likes
on
0 Posts
Re: How many bolt turns to reach .010-.020 lifter preload???
1/2 to a half turn will be fine. I ran compR's at 50+ thousanths preload and they worked just the same btw. No change in noise or performance. <shrug> I had a whole bunch of different pushrods so I tried different preloads to see if it mattered.
#9
TECH Enthusiast
Join Date: Jan 2002
Location: Orange Park, FL
Posts: 597
Likes: 0
Received 0 Likes
on
0 Posts
Re: How many bolt turns to reach .010-.020 lifter preload???
I installed my Yella Terra's with no shims on Comp R's w/ a TR224, 7.4 PR's, and milled .015 heads. After a few WOT runs it sounded as it lifters were collapsed. Talked to Comp Cams and was told I had WAY too much pre-load. I installed the shims provided by Yella Terra and the "collapsing" lifter noise went away but it is one noisy *** valve train now. I'm wondering if I should try some shims of different thinckness now to try and get it a little quieter (if thats possible).
#10
Re: How many bolt turns to reach .010-.020 lifter preload???
What do you use to shim the stock valvetrain??
I got the Comp Rs so they dont bleed down in the upper RPMs (6800-7000) Itll be a couple weeks before I can get the YTs to get the preload right and want to make sure I dont hurt anything
I got the Comp Rs so they dont bleed down in the upper RPMs (6800-7000) Itll be a couple weeks before I can get the YTs to get the preload right and want to make sure I dont hurt anything
#11
TECH Addict
iTrader: (4)
Join Date: Nov 2001
Location: Sugar Land, TX
Posts: 2,485
Likes: 0
Received 0 Likes
on
0 Posts
Re: How many bolt turns to reach .010-.020 lifter preload???
You can calculate number of turns required to get your .010 or .020 preloading.
I don't know what bolt thread size our heads have but if it's 5/16-24 for example then divide 1" by number of threads per inch = 1/24 = .0417 per turn. For .020 then divide .020 by .0417 = .48 turns or right at 1/2 turn.
I don't know what bolt thread size our heads have but if it's 5/16-24 for example then divide 1" by number of threads per inch = 1/24 = .0417 per turn. For .020 then divide .020 by .0417 = .48 turns or right at 1/2 turn.
#12
Re: How many bolt turns to reach .010-.020 lifter preload???
You can calculate number of turns required to get your .010 or .020 preloading.
I don't know what bolt thread size our heads have but if it's 5/16-24 for example then divide 1" by number of threads per inch = 1/24 = .0417 per turn. For .020 then divide .020 by .0417 = .48 turns or right at 1/2 turn.
I don't know what bolt thread size our heads have but if it's 5/16-24 for example then divide 1" by number of threads per inch = 1/24 = .0417 per turn. For .020 then divide .020 by .0417 = .48 turns or right at 1/2 turn.
#13
TECH Veteran
iTrader: (1)
Re: How many bolt turns to reach .010-.020 lifter preload???
Finger tighten rocker arm bolt until you can barely spin the pushrod with one finger. This is the "zero lash point" where there is no preload on the lifter. Now torque the bolt counting turns until the instant the bolt stops turning with the wrench. If you get more than one full 360* turn you must install shims. Now torque the bolt to 25 ft-lbs if using Yella Terras, 22 ft-lbs for stock rockers. 1/4 turn = 10-12 thou of preload, so that's how much you want for Comp R's.
#16
TECH Addict
iTrader: (4)
Join Date: Nov 2001
Location: Sugar Land, TX
Posts: 2,485
Likes: 0
Received 0 Likes
on
0 Posts
Re: How many bolt turns to reach .010-.020 lifter preload???
You can calculate number of turns required to get your .010 or .020 preloading.
I don't know what bolt thread size our heads have but if it's 5/16-24 for example then divide 1" by number of threads per inch = 1/24 = .0417 per turn. For .020 then divide .020 by .0417 = .48 turns or right at 1/2 turn.
I don't know what bolt thread size our heads have but if it's 5/16-24 for example then divide 1" by number of threads per inch = 1/24 = .0417 per turn. For .020 then divide .020 by .0417 = .48 turns or right at 1/2 turn.
All I'm doing is dividing the number of threads/inch into one inch to see how far one turn compresses the lifter. With one turn known you can then calculate the portion of a turn required to compress number of thousandths desired.
#17
Re: How many bolt turns to reach .010-.020 lifter preload???
Thanks guys, I just wanted to make sure 1/4 turn (very rough guess) is a ballpark. When I get my YTs, then Ill caheck it with a dial gauge to get it exact
Vince... Im more that capable of building my own motor
Vince... Im more that capable of building my own motor
#18
Shorty Director
iTrader: (1)
Re: How many bolt turns to reach .010-.020 lifter preload???
Carl I could have built a 100 unit apartment complex by now.. What is the hold up man?? I am getting a little tired of beating the same people in our area.. Hurry up and get your car done so I can smack you around as well. Oh yeah, I heard you mentioned that the reason you got rid of your TEA heads were because YOU think they are subpar heads.. Hmmmmm. How many slow TEA headed cars in our area..? Ford or GM.. Pls do not take any of my comments the wrong way.. You know I do not mean any harm.. I am just hyping up a kill story, I mean race..
#19
Re: How many bolt turns to reach .010-.020 lifter preload???
Hey Vince.. Parts cost money and Im not a big baller like you I was doning good for a long time to not get my stuff repoed. The economy is in the toilet and my job was also
LOL about the heads... Let Al know that I had to sell them along with other stuff to pay bills man, thats all.. I dont think of them as "subpar" persay, but I learned some things that arent public and they are going to stay that way I got a set of heads matched for setup, not just an off the shelf CNCed head. Like I said before Im not bashing Brandons work. He does good work, especially his exhaust work
Also, bring it tall one. Itll be a long time before I can lay into it as Ill need a dyno tune and fix a few things I want first
LOL about the heads... Let Al know that I had to sell them along with other stuff to pay bills man, thats all.. I dont think of them as "subpar" persay, but I learned some things that arent public and they are going to stay that way I got a set of heads matched for setup, not just an off the shelf CNCed head. Like I said before Im not bashing Brandons work. He does good work, especially his exhaust work
Also, bring it tall one. Itll be a long time before I can lay into it as Ill need a dyno tune and fix a few things I want first
#20
Shorty Director
iTrader: (1)
Re: How many bolt turns to reach .010-.020 lifter preload???
You mean I have to wait longer to run you???? I asked you a long time ago why you were getting rid of the heads and you gave me a brief scenario on how you felt about them and that you just flat out needed the money. Two weeks ago while at our speed proving grounds a discussion about local h/c packages came up and someone in our group brought up YOUR thoughts about TEA heads. I had plans of asking you about it then, but never got around to it. I see this post about your cam choice and I am like he had the PERFECT HEADS for that cam.. Why do I need to let Al know about your financial status? Were you thinking of using Brandon and his services? I do not even know all the particulars. I only know what you tell some of the peeps on Badrap.. Brandon knows he does good work. He has many cars out there to prove it.. We all know you are going to come out with something.. I am just surprised it is taking you so long.. No one is doubting your ability to get the job done, we are just waiting on you to get the job done.