LS7 Lifter problems?
LS7 Lifter problems? As if I have not had enough problems with this freakin thing I have a tap now. This thing has like 200 miles on it since I got it back together again. I set the preload to a tad past 1/2 turn and it was ok just a tad bit noisey and so I thought well let me just go ahead and try 3/4 turn preload and now it's got a noticble tap when I am driving. Checked for exhaust leaks.. there are none. Took a screew drive to the valve cover and as I move it along the cover I can here the individual rockers taping. Put my ear to the oil pan and the bottom end sounds fine. It's maybe 3 of them but one is the one that is noticable tick while driving. oil pressure is good and at start up you here it for a few seconds and then it's almost gone until it comes up to temp and then it gose back to being there. It's not bad as in wow I have a lifter tap but it's louder then it's ever been before even at the 1/2 turn mark. I didn't even take these things out of the bores when I had the heads off so I am stumped as to why it's so much louder other then their freakin LS7 POS noisey *** lifters. Should I try less preload since it seemed quieter with only the 1/2 turn? I am almost positive every one of them was done on the back side of the lobe. I freakin hand turned the engine to make sure I could see where I was in the cycles and not go past to a ramp. I don't feel like taking that GD intake off. It runs good other then that. really dose not get any louder with more rpms under load.
Yea that would be my first guess too is all your geometry good?
Lifters are fairly simple so to have 3 of them bad I would highly doubt it...
Also I know you said you checked for exhaust leaks...but when we put one of my friends car back together he had a tapping noise too and we checked everything (we thought) turned out to be a leaking header gasket that you couldn't see unless you held your mouth just right...
Lifters are fairly simple so to have 3 of them bad I would highly doubt it...
Also I know you said you checked for exhaust leaks...but when we put one of my friends car back together he had a tapping noise too and we checked everything (we thought) turned out to be a leaking header gasket that you couldn't see unless you held your mouth just right...
God knows with this thing. it has been such a mess from the start due mostley to a 3rd party who built it. I would imagine the geometry is fine since there is only really one somewhat loud tap you can hear while driving. others are as quiet as roller rockers can be as I move the screwdriver around the valve cover. It's not really 3 that are bad, it sounds like one that is noticble just standing next to it and the other two you can hear they are louder then the others when you listen with a screwdrive up to the valve covers. The rest sound perfect and I did check every pushrod to make sure they where straight and the same size. I think I am going to go back to 1/2 turn and run it with the covers off and see if it changes. Also I may check the contact area on the valve stems to make sure they are the correct size push rods. Whats the best way to do this? With a sharpie?
"Back side of the lobe??" With ANY "quick bleed" hydraulic lifter you need to set them while the engine is running. Loosen the adjuster and let it "tap" a few seconds to be sure the lifter is all the way up. Then bring it down to where you want it. LS7 lifters don't allow enough oil up the pushrod to squirt you, but it's still messy. If you cover the wheel wells with a drop cloth, watch the headers. Oily rags and hot headers are a recipe for trouble.
Al 95 Z28
Al 95 Z28
"Back side of the lobe??" With ANY "quick bleed" hydraulic lifter you need to set them while the engine is running. Loosen the adjuster and let it "tap" a few seconds to be sure the lifter is all the way up. Then bring it down to where you want it. LS7 lifters don't allow enough oil up the pushrod to squirt you, but it's still messy. If you cover the wheel wells with a drop cloth, watch the headers. Oily rags and hot headers are a recipe for trouble.
Al 95 Z28
Al 95 Z28
I'm missing the point as to why I would have to do it while it is running with full roller rockers and polly locks. As I understand it the LS7's have a spring inside that keeps the hat at the top of the lifter with no load. Zero lash is not going to depress this untill I turn for preload. Why should it be running or is this just a better way to do it then the way I did them? I had been told not to exceed a full turn other wise the valve may hang open. When I said the back side of the lobe I ment the base meaning 180* from the top of the lobe or highest lift point.
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man another post, i hate reading them when its your car now haha. I still think that car is awesome! hate reading that she is breaking all the time.
Ive seen tons of vids of adjusting when its running, i would guess its so you can hear everything a little better and know what your doing and how its effecting sound and you can pin point things more easily. It could be comming from the one next to where you think it is lol.
Saw that 3rd party crapola. I wont even deal with 2nd party crapola anymore, i do **** myself, i learn more, i save money, and i only get to blame myself!
Ive seen tons of vids of adjusting when its running, i would guess its so you can hear everything a little better and know what your doing and how its effecting sound and you can pin point things more easily. It could be comming from the one next to where you think it is lol.
Saw that 3rd party crapola. I wont even deal with 2nd party crapola anymore, i do **** myself, i learn more, i save money, and i only get to blame myself!
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TECH Regular
Joined: Jul 2006
Posts: 452
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From: Sacramento, CA
did you back em out to 1/2 turn yet? should't take you that long. I remember i had a similar problem on my nova and I over tightened one of the rockers.. Just do the cheapest method before buying anything
I'm missing the point as to why I would have to do it while it is running with full roller rockers and polly locks. As I understand it the LS7's have a spring inside that keeps the hat at the top of the lifter with no load. Zero lash is not going to depress this untill I turn for preload. Why should it be running or is this just a better way to do it then the way I did them? I had been told not to exceed a full turn other wise the valve may hang open. When I said the back side of the lobe I ment the base meaning 180* from the top of the lobe or highest lift point.
By operating the engine you take the load off the rocker nut until you hear the clatter. Then you slowly turn until the clatter stops and lock it down. You know that this way the lifter is lubricated and primed. There are a 1000 ways to skin a cat, this is just one of them.
lmfao Shouldn't but I have ASR so I have to dig in there and remove that POS. and remove the alt so I can get the valve cover off. I dred it lol. I wont have time to do it for about 2 weeks unless there is a break in the schedual one evening.
It's not that your way is wrong. IDK how you are 100% sure you are on base without using a dial indicator. Even by those methods you cannot be sure that the lifter is 100% primed and pumped up. Yes they have a spring in them to assist with this but I can assure you that if you press one down with no fluid vs one with fluid there is a difference.
By operating the engine you take the load off the rocker nut until you hear the clatter. Then you slowly turn until the clatter stops and lock it down. You know that this way the lifter is lubricated and primed. There are a 1000 ways to skin a cat, this is just one of them.
By operating the engine you take the load off the rocker nut until you hear the clatter. Then you slowly turn until the clatter stops and lock it down. You know that this way the lifter is lubricated and primed. There are a 1000 ways to skin a cat, this is just one of them.
Last edited by jaycenk; May 17, 2011 at 09:58 PM.
TECH Regular
Joined: Jul 2006
Posts: 452
Likes: 0
From: Sacramento, CA
You know what you signed up for when you bought one
it makes no difference whether you set the preload engine running or not. As far as needing a dial indicator to make sure you're on the base circle... I've run small cams and big cams and have never come close to coming off the base circle with the IVC-adjust exhaust, EVO-adjust intake method.
it makes no difference whether you set the preload engine running or not. As far as needing a dial indicator to make sure you're on the base circle... I've run small cams and big cams and have never come close to coming off the base circle with the IVC-adjust exhaust, EVO-adjust intake method.
If you do it with the engine running, and fully up to temperature, it also allows all the various, dis-similar metals to reach their "heated" dimensions, and give you an accurate setting.
BTW, those "oil deflectors" that were mentioned in an earlier post, only work on the stock rockers....
BTW, those "oil deflectors" that were mentioned in an earlier post, only work on the stock rockers....
it makes no difference whether you set the preload engine running or not. As far as needing a dial indicator to make sure you're on the base circle... I've run small cams and big cams and have never come close to coming off the base circle with the IVC-adjust exhaust, EVO-adjust intake method.
BTW, those "oil deflectors" that were mentioned in an earlier post, only work on the stock rockers....
