***7.450 push rods***
Team Owner
Joined: Mar 1999
Posts: 22,025
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From: At the beach in little Rhody
^ Not according to the directions that came w/ my YTs. It says nothing about adjusting for wipe, it only speaks of pre-load.
It tells you to firs test w/o shims, if it takes over 1 full turn to get from finger tight to wrench tight then you need the shims.
I still have the paper at home for the exact wording.
It tells you to firs test w/o shims, if it takes over 1 full turn to get from finger tight to wrench tight then you need the shims.
I still have the paper at home for the exact wording.
Race Director
Joined: Oct 2002
Posts: 16,477
Likes: 26
From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
The wipe pattern will certainly change if you shim the rockers...but so will the ideal pushrod length too....so shimming affects both.
Changing pushrod length, however, won't change the wipe pattern, it will only change the lifter preload.
It would seem logical to check the wipe pattern first, shim the rockers if needed, and then check and size the pushrods to obtain proper preload....yes?
Changing pushrod length, however, won't change the wipe pattern, it will only change the lifter preload.
It would seem logical to check the wipe pattern first, shim the rockers if needed, and then check and size the pushrods to obtain proper preload....yes?
Melting Slicks
Joined: Jul 2006
Posts: 3,356
Likes: 1
From: Chesapeake Va
The wipe pattern will certainly change if you shim the rockers...but so will the ideal pushrod length too....so shimming affects both.
Changing pushrod length, however, won't change the wipe pattern, it will only change the lifter preload.
It would seem logical to check the wipe pattern first, shim the rockers if needed, and then check and size the pushrods to obtain proper preload....yes?
Changing pushrod length, however, won't change the wipe pattern, it will only change the lifter preload.
It would seem logical to check the wipe pattern first, shim the rockers if needed, and then check and size the pushrods to obtain proper preload....yes?
The "wipe" pattern, or the movement of the roller across the tip, is determined by several things. The most important thing being the fulcrum, or pivot point, in relation to the tip of the valve.
The best way to determine the optimal fulcrum point is with a solid roller lifter and/or checker springs, an adjustable pushrod, a roller tip rocker, and some shims.
But, not to over complicate things, for the most part, on the LSx based motors, with rockers made specific for them, XX amount of preload, combined with an adequate wipe pattern, should yeild a quiet valvetrain.
The most important thing is to make sure you have some preload. That amount can be anywhere from .050 to over .100. Doesnt really matter, as far as 'm concerned. You only need to get the plunger in the middle of its travel.
I've seen em quiet with 1/2 a turn of preload, up to 1.5 turns of preload.
Last edited by edcmat-l1; Aug 24, 2007 at 07:46 AM.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
The wipe pattern will certainly change if you shim the rockers...but so will the ideal pushrod length too....so shimming affects both.
Changing pushrod length, however, won't change the wipe pattern, it will only change the lifter preload.
It would seem logical to check the wipe pattern first, shim the rockers if needed, and then check and size the pushrods to obtain proper preload....yes?
Changing pushrod length, however, won't change the wipe pattern, it will only change the lifter preload.
It would seem logical to check the wipe pattern first, shim the rockers if needed, and then check and size the pushrods to obtain proper preload....yes?
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
For Deno, sorry I sidetracked your thread, have you checked the pushrod engagement with the rocker? Do your pushrods have a "ball" head or are they straight and then formed to a ball (Stock are ball ends). Some of the straight pushrods will contact the edge of the pushrod cup area on an aftermarket pushrod and this will tick. You may want to pull the HS and check for any indication of contact in the pushrod cup area. I really think you have a valve train geometry issue as opposed to a pushrod length issue that is the cause of your noise. The one video sounds very bad.
Also, which springs are you running and do you have clearance between the spring retainer and the rocker at all points in the rocker sweep?
Also, which springs are you running and do you have clearance between the spring retainer and the rocker at all points in the rocker sweep?
Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
For Deno, sorry I sidetracked your thread, have you checked the pushrod engagement with the rocker? Do your pushrods have a "ball" head or are they straight and then formed to a ball (Stock are ball ends). Some of the straight pushrods will contact the edge of the pushrod cup area on an aftermarket pushrod and this will tick. You may want to pull the HS and check for any indication of contact in the pushrod cup area. I really think you have a valve train geometry issue as opposed to a pushrod length issue that is the cause of your noise. The one video sounds very bad.
Also, which springs are you running and do you have clearance between the spring retainer and the rocker at all points in the rocker sweep?
Also, which springs are you running and do you have clearance between the spring retainer and the rocker at all points in the rocker sweep?
straight and then formed to a ball << is what I have.
You may want to pull the HS and check for any indication of contact in the pushrod cup area.[COLOR="red"][COLOR="Black"] As I recall but will check again the push rods are in the cup of the rockers.
The springs are the ones that come with the Patriot heads. I'll check the sweep area.
Thanks,
Sleeper
Last edited by SLPRC5; Aug 24, 2007 at 07:55 PM.
Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
Well, Sleeper, the plot thickens!
This is fun, gets my old Retired Engineer juices flowing.
Shimming the pedestal will certainly affect the wipe pattern a bit, as the fulcrum point of the rocker arm is changed. Maybe it's not much, but many of the guys on the Forum have discussed it in relation to the various after-market rockers. I can see it possibly making noise if off a bit. Certainly the wear/stress issue is real if it's not correct.
I guess if it was me, I would first shoot for a verified 0.80 - 0.120 lifter pre-load to start. If in that range, the lifters should be pretty happy.
Then, take a close look at the valve stem wipe pattern to insure it's good.
Others with more experience on the LS1 can correct me, but
on the old engines, we marked the valve stem with a Sharpie, and tried to get the most centered "rub spot" on the valve stem as the rocker arm moved the valve fully up and down.
If I remember correctly, I don't think PR length or lifter pre-load has any affect on wipe pattern; only pedestal ht, cam base circle, and head design/geometry will change these. (and of course, rocker arm design/geometry, if different from stock.)
SON OF A GUN, YOU CHANGED ALL OF THESE!
So, better check that wipe pattern.
Check Comp Cams web site, lots of good "wipe" info there.
So, if the wipe is good and centered on the valve stem, then leave the pedestals alone (or try the pedestals on one set and see how the wipe changes.
Pick the wipe/pedestal combo that looks best.
Then,
Pick the lifter preload you want. (my guess, .100-.120 will be quietest - no flames please.)
Do the math and select the proper PR.
If none of that works, well, re-install the old LS6 cam - ha!
Keep us informed on progress - interesting project.
Cheers,
DG
This is fun, gets my old Retired Engineer juices flowing.
Shimming the pedestal will certainly affect the wipe pattern a bit, as the fulcrum point of the rocker arm is changed. Maybe it's not much, but many of the guys on the Forum have discussed it in relation to the various after-market rockers. I can see it possibly making noise if off a bit. Certainly the wear/stress issue is real if it's not correct.
I guess if it was me, I would first shoot for a verified 0.80 - 0.120 lifter pre-load to start. If in that range, the lifters should be pretty happy.
Then, take a close look at the valve stem wipe pattern to insure it's good.
Others with more experience on the LS1 can correct me, but
on the old engines, we marked the valve stem with a Sharpie, and tried to get the most centered "rub spot" on the valve stem as the rocker arm moved the valve fully up and down.
If I remember correctly, I don't think PR length or lifter pre-load has any affect on wipe pattern; only pedestal ht, cam base circle, and head design/geometry will change these. (and of course, rocker arm design/geometry, if different from stock.)
SON OF A GUN, YOU CHANGED ALL OF THESE!
So, better check that wipe pattern.
Check Comp Cams web site, lots of good "wipe" info there.
So, if the wipe is good and centered on the valve stem, then leave the pedestals alone (or try the pedestals on one set and see how the wipe changes.
Pick the wipe/pedestal combo that looks best.
Then,
Pick the lifter preload you want. (my guess, .100-.120 will be quietest - no flames please.)
Do the math and select the proper PR.
If none of that works, well, re-install the old LS6 cam - ha!
Keep us informed on progress - interesting project.
Cheers,
DG
I'll check the wipe pattern...I know it will quiet down after being done correctlt and there will be no need for the ZO6 cam re-install...
Sleeper
Last edited by SLPRC5; Aug 30, 2007 at 02:25 AM.
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Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
straight and then formed to a ball << is what I have.
You may want to pull the HS and check for any indication of contact in the pushrod cup area.[COLOR="red"][COLOR="Black"] As I recall but will check again the push rods are in the cup of the rockers.
The springs are the ones that come with the Patriot heads. I'll check the sweep area.
Thanks,
Sleeper
You may want to pull the HS and check for any indication of contact in the pushrod cup area.[COLOR="red"][COLOR="Black"] As I recall but will check again the push rods are in the cup of the rockers.
The springs are the ones that come with the Patriot heads. I'll check the sweep area.
Thanks,
Sleeper
Here are the area's to look at for contact. Contact near the pushrod cup will also shift the pushrod laterally (or try to). Contact near the spring would be due to the large retainer on a dual spring. Since the HS rockers are anodized, you should see something just by inspection.
Melting Slicks
Joined: Jul 2006
Posts: 3,356
Likes: 1
From: Chesapeake Va
This is true. And I forgot to list checking springs. They def make life much easier, esp with hyd lifters. Will go back and edit post.
Team Owner
Joined: Mar 2001
Posts: 25,889
Likes: 7
From: Virginia Beach
CI 3-5-6-7-8 Veteran
I'm confused... the YT directions specificaly say the shims are to be used if proper pre-load cannot be achieved w/o them. It says nothing of wipe pattern other than to check it.
It makes sense that shimming the rockers would change the fulcrum point and therefore adjust wipe patter on the valve tip... but LS1howto and YT said otherwise.
I did run the motor up and down when I had them in to check them, but had no sharpie etc. The motors been running great for 7k since cam install etc... should I get in there and do a closer check?
It makes sense that shimming the rockers would change the fulcrum point and therefore adjust wipe patter on the valve tip... but LS1howto and YT said otherwise.
I did run the motor up and down when I had them in to check them, but had no sharpie etc. The motors been running great for 7k since cam install etc... should I get in there and do a closer check?
Team Owner
Joined: Mar 2001
Posts: 25,889
Likes: 7
From: Virginia Beach
CI 3-5-6-7-8 Veteran
OK: I thought about this for a bit. The shims may affect wipe pattern, but they most definately affect pre-load as YT says they will.
If you tighten the rocker arm finger tight to zero lash, then it takes over 1 turn to get wrench tight you are putting too much pre-load on the lifters.
If you install the shim, you have moved the rocker arm up slightly. So from zero-lash to wrench tight will take less turns and put less pre-load on the lifter.
Makes sense in my head... correct me if I'm wrong. Shimming may indeed affect wipe, but it's primary application is to reduce pre-load. Obviously, this would also be affected by PR length.
If you tighten the rocker arm finger tight to zero lash, then it takes over 1 turn to get wrench tight you are putting too much pre-load on the lifters.
If you install the shim, you have moved the rocker arm up slightly. So from zero-lash to wrench tight will take less turns and put less pre-load on the lifter.
Makes sense in my head... correct me if I'm wrong. Shimming may indeed affect wipe, but it's primary application is to reduce pre-load. Obviously, this would also be affected by PR length.
Melting Slicks
Joined: May 2005
Posts: 3,394
Likes: 12
From: Leon Iowa
St. Jude Donor '06-'07-'08-'09
Hey Deno, your rockers are not adjustable are they? Also the drawing that vettenuts drew out is the contacy problem just on the yellow T rockers or is it also on the stockers?
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
OK: I thought about this for a bit. The shims may affect wipe pattern, but they most definately affect pre-load as YT says they will.
If you tighten the rocker arm finger tight to zero lash, then it takes over 1 turn to get wrench tight you are putting too much pre-load on the lifters.
If you install the shim, you have moved the rocker arm up slightly. So from zero-lash to wrench tight will take less turns and put less pre-load on the lifter.
Makes sense in my head... correct me if I'm wrong. Shimming may indeed affect wipe, but it's primary application is to reduce pre-load. Obviously, this would also be affected by PR length.
If you tighten the rocker arm finger tight to zero lash, then it takes over 1 turn to get wrench tight you are putting too much pre-load on the lifters.
If you install the shim, you have moved the rocker arm up slightly. So from zero-lash to wrench tight will take less turns and put less pre-load on the lifter.
Makes sense in my head... correct me if I'm wrong. Shimming may indeed affect wipe, but it's primary application is to reduce pre-load. Obviously, this would also be affected by PR length.
Team Owner
Joined: Mar 2001
Posts: 25,889
Likes: 7
From: Virginia Beach
CI 3-5-6-7-8 Veteran
^ That is why YT's instructions avoids that part... shimming the rocker up would move the wipe pattern "back" toward the manifold right?
It makes sense to set that then get proper pushrods, however, assuming your pushrods are of acceptable length, as mine were, adding the shims would get you less pre-load, as shimming lessense the distance the rocer arm unit can move dowm when going from zero lash to wrench tight.
It makes sense to set that then get proper pushrods, however, assuming your pushrods are of acceptable length, as mine were, adding the shims would get you less pre-load, as shimming lessense the distance the rocer arm unit can move dowm when going from zero lash to wrench tight.
Le Mans Master
Joined: Dec 2003
Posts: 5,561
Likes: 448
From: Atlanta metro Ga.
I view it opposite, shims will set the wipe pattern. Once set, measure for pushrod. However, using the shims will definitely affect pushrod length. We measured this morning and he needs a 7.475 or 7.500" pushrod to get the correct preload. So to say the least, we are at all stop
Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
^ That is why YT's instructions avoids that part... shimming the rocker up would move the wipe pattern "back" toward the manifold right?
It makes sense to set that then get proper pushrods, however, assuming your pushrods are of acceptable length, as mine were, adding the shims would get you less pre-load, as shimming lessense the distance the rocer arm unit can move dowm when going from zero lash to wrench tight.
It makes sense to set that then get proper pushrods, however, assuming your pushrods are of acceptable length, as mine were, adding the shims would get you less pre-load, as shimming lessense the distance the rocer arm unit can move dowm when going from zero lash to wrench tight.
Racer
Joined: Sep 2000
Posts: 373
Likes: 0
From: Wakefield R.I.
Hey Sleeper - Its my car that Vettenuts is working on and Yes the shims were in the package(.045 thick). I just ordered my 7.500 p.rods.
When we put the shims in the wipe moved about 1/32" to center and is now dead on. That caused the the need for extra lenght rods.
It will be fun to see who gets all this right first.
Good luck
BTW I have sent Vettenuts to the beach for some R & R which he really needs after all this.
When we put the shims in the wipe moved about 1/32" to center and is now dead on. That caused the the need for extra lenght rods.
It will be fun to see who gets all this right first.
Good luck
BTW I have sent Vettenuts to the beach for some R & R which he really needs after all this.
Last edited by 04BlueGoose; Aug 24, 2007 at 02:27 PM. Reason: add info