How to diagnose a failing lifter(s)
08-10-2010, 01:10 PM
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How to diagnose a failing lifter(s) I have recently completed my 1st LS1 H/C/I build and like so many others, I am now chasing some valve train noise... I have read SOOO many "sewing machine", lifter, rocker, push rod threads in the last two days, my eyes are bleeding! I confirmed a lot of my theory's and learned a few tricks, but nothing that exactly matched or difinitevly diagnosed my problem..
I for the most part, now understand the theory of lifter pre-load, p/r measuring techniques, torque sequence, zero lash, etc.. Just for reference, i tore into an '04 LS1 with 14k miles and used TSP 5.3 CNC heads w/ dual springs, Pat G. cam approx. .228/.231 & .614/.617 and the recommended 7.425 pushrods.. (not realizing at the time that measuring was the best way)
Long story short, I got the motor running and immeiately had some inconsistent valve train clatter around 18-1900 RPM - mostly evident on the pass side rear, which seemed to get worse the hotter the motor got.. After doing some research, I thought maybe my push rods were in fact too short, not having enough pre-load..
Again, without checking, I installed a set of 7.450's and it didnt seem to help at all.. This time I did all the reading and got a push rod length checker..
Cylinder #1 - both valves closed, I was getting 7.338 Intake and 7.319 Exhaust with the comp cam 6.800 checker. Adding .075 pre-load says I should be using roughly a 7.400 p/r?
Now with Shane from Thunder Racings 1-1/4 to 1-3/4 to 22 ft-lb measurement method, I was getting abour 1-1/8 turns with the 7.425's and 1-5/8 turns with the 7.450's - all to 22ft-lbs from zero lash. Although quite a bit longer than the checker said I should use, they both fall very close to Shanes range??
Before I try the 7.400's, my thought was that shorter pushrod might allow for even more valve train noise than I have right now!
This brings me to my real question.. Could my problem be the stock LS1 lifters are failing and allowing the clatter? Are the dual valve springs compounding the problem of maybe a weak lifter? My plan was to buy a set of LS7 lifters and new trays and start from scratch, but I hate to keep throwing time and money at it if I am not sure of the problem.. Has anyone cured a similar diagnosis with new lifters alone? Would I be farther ahead to try a set of 7.400's before pulling the heads off?? I'm lost for direction at the moment and would appreicate any help.. Thanks guys.
I for the most part, now understand the theory of lifter pre-load, p/r measuring techniques, torque sequence, zero lash, etc.. Just for reference, i tore into an '04 LS1 with 14k miles and used TSP 5.3 CNC heads w/ dual springs, Pat G. cam approx. .228/.231 & .614/.617 and the recommended 7.425 pushrods.. (not realizing at the time that measuring was the best way)
Long story short, I got the motor running and immeiately had some inconsistent valve train clatter around 18-1900 RPM - mostly evident on the pass side rear, which seemed to get worse the hotter the motor got.. After doing some research, I thought maybe my push rods were in fact too short, not having enough pre-load..
Again, without checking, I installed a set of 7.450's and it didnt seem to help at all.. This time I did all the reading and got a push rod length checker..
Cylinder #1 - both valves closed, I was getting 7.338 Intake and 7.319 Exhaust with the comp cam 6.800 checker. Adding .075 pre-load says I should be using roughly a 7.400 p/r?
Now with Shane from Thunder Racings 1-1/4 to 1-3/4 to 22 ft-lb measurement method, I was getting abour 1-1/8 turns with the 7.425's and 1-5/8 turns with the 7.450's - all to 22ft-lbs from zero lash. Although quite a bit longer than the checker said I should use, they both fall very close to Shanes range??
Before I try the 7.400's, my thought was that shorter pushrod might allow for even more valve train noise than I have right now!
This brings me to my real question.. Could my problem be the stock LS1 lifters are failing and allowing the clatter? Are the dual valve springs compounding the problem of maybe a weak lifter? My plan was to buy a set of LS7 lifters and new trays and start from scratch, but I hate to keep throwing time and money at it if I am not sure of the problem.. Has anyone cured a similar diagnosis with new lifters alone? Would I be farther ahead to try a set of 7.400's before pulling the heads off?? I'm lost for direction at the moment and would appreicate any help.. Thanks guys.
08-10-2010, 01:45 PM
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The stock lifters with 14k miles on them should be able to handle that cam fine. Check all of your geometry make sure the tip of the rocker is staying on the valve stem at all points of rotation.
08-10-2010, 03:37 PM
#5
Shane's method from TR is pretty good, BUT can be skewed heavily by your own setting of "zero lash." I started with his method, got something around 7.375" PRs. I then used the adjustable checker and cam up with 7.400"-7.425". I then attempted TR method again, and was a little more precise with "zero lash". This confirmed the 7.425" PRs. I then went ahead and got out a sharpie and colored the tip of the valve. I let it dry for about 3-5 minutes, making sure that just torquing the rocker didn't skew my wipe. I still have the stock rockers and they are non-adjustable, but I wanted to see the difference between the 7.400" and the 7.425" PRs. The wipe was dead nuts center with the 7.425" and a little high with the 7.400" PRs. All in all I re-checked everything again, all (3) methods, and came up with 7.425" PRs on multiple cylinders.
A shorter PR will give a louder valvetrain noise, but then again, so will a PR that is too long. Lets say you measured and re-measured and came up with an average of 7.3875" PR length. Since off-the-shelf PRs only come in 0.025" increments, that is when you can use the comparison of shorter = louder and in that case I would go with 7.400" PRs.
A shorter PR will give a louder valvetrain noise, but then again, so will a PR that is too long. Lets say you measured and re-measured and came up with an average of 7.3875" PR length. Since off-the-shelf PRs only come in 0.025" increments, that is when you can use the comparison of shorter = louder and in that case I would go with 7.400" PRs.
08-10-2010, 04:03 PM
#6
It's gonna make some noise regardless. Every time I use strong dual springs it makes more noise than w/ stock springs. Don't worry about it. If the wipe pattern is centered & as thin as possible, she is good.
08-10-2010, 04:35 PM
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I understand its going to make some noise.. I expect a little sewing machine noise, but this is a pretty loud clatter at around 18-1900rmp.. Something is obviously wrong.. In fact I took the car to be dyno tuned at a very reputable shop and they said something is wrong and they wouldnt make any pulls over about 2-3k - eventually sending me on my way to figure the problem out..
Last edited by Racinjason424; 08-10-2010 at 04:44 PM.
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08-10-2010, 04:42 PM
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Shane's method from TR is pretty good, BUT can be skewed heavily by your own setting of "zero lash." I started with his method, got something around 7.375" PRs. I then used the adjustable checker and cam up with 7.400"-7.425". I then attempted TR method again, and was a little more precise with "zero lash". This confirmed the 7.425" PRs. I then went ahead and got out a sharpie and colored the tip of the valve. I let it dry for about 3-5 minutes, making sure that just torquing the rocker didn't skew my wipe. I still have the stock rockers and they are non-adjustable, but I wanted to see the difference between the 7.400" and the 7.425" PRs. The wipe was dead nuts center with the 7.425" and a little high with the 7.400" PRs. All in all I re-checked everything again, all (3) methods, and came up with 7.425" PRs on multiple cylinders.
A shorter PR will give a louder valvetrain noise, but then again, so will a PR that is too long. Lets say you measured and re-measured and came up with an average of 7.3875" PR length. Since off-the-shelf PRs only come in 0.025" increments, that is when you can use the comparison of shorter = louder and in that case I would go with 7.400" PRs.
A shorter PR will give a louder valvetrain noise, but then again, so will a PR that is too long. Lets say you measured and re-measured and came up with an average of 7.3875" PR length. Since off-the-shelf PRs only come in 0.025" increments, that is when you can use the comparison of shorter = louder and in that case I would go with 7.400" PRs.
08-10-2010, 06:53 PM
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swapped back to 7.425's.. Swapped back to 7.425's tonight re-checked and re-torqued everything in sequence.. Approx. 1-1/8 to 1-1/4 turns.. #2 & #3 exhasust still around 2 turns - same as before?? Other than a little sewing machine sound, there is absolutely no clattering at idle. Took for a test drive and it still clatters pretty good between all gears up shifting and down shifting.. Cant really hear the sewing machine sound in the car, just the clatter.. It's driving me nuts!!!! I could try the 7.400's like the push rod checker said, but wouldnt going from 7.425's to 7.400's make everything looser and promote more clattering??? I'm still thinking lifters in the back of my mind, I just dont know any way to pin-point it and nobody else has said for sure it sounded like lifters.. I hope to find someone with my same exact diagnosis that cured the problem with a lifter swap!!!! please, oh please oh please!!!!
08-10-2010, 08:27 PM
#12
EO - exhaust open for the intake side
IC - intake close for the exhaust side
08-10-2010, 08:52 PM
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?? The intake should start to open before the exhaust closes (overlap)! Do this one port at a time, wait until the exhaust starts to open. When the exhaust starts to open, you know the intake is on the base circle. Then for the exhaust, wait until the intake is closing, then you know the exhaust is on the base circle.
EO - exhaust open for the intake side
IC - intake close for the exhaust side
EO - exhaust open for the intake side
IC - intake close for the exhaust side
Exhaust 1,2,7 & 8
Intake 1,3,4 & 5
Rotate Crank 360' then torque the following to 22 ft-lbs
Exhaust 3,4,5 & 6
Intake 2,6,7 & 8
Is this the same order you would do Shane's method? I dont belive in his write up that he tells you to roll the crank '360? Maybe it's assumed..
I got this info from LS1 Tech in a thread. The instructions are called Document ID# 642776 2001 Chevrolet/ Geo Camaro "Valve Rocker Arm and Push Rod Replacement". Looks like a GM instruction sheet.. Does this sound right, or do you have to rotate the motor and torque each valve individually after it's on the base circle per your above instructions? You're not in Michigan by chance are you?? :-)
08-10-2010, 09:17 PM
#14
I will have to double check that.. Dad was helping and it sound like he knew what he was talking about! (he's an old school - gen I guru :-) Are you saying you cant torque both #1 lifters at the same time? I thought I had both #1's closed and I torqued to 22 ft-lbs in this sequence.
Exhaust 1,2,7 & 8
Intake 1,3,4 & 5
Rotate Crank 360' then torque the following to 22 ft-lbs
Exhaust 3,4,5 & 6
Intake 2,6,7 & 8
Is this the same order you would do Shane's method? I dont belive in his write up that he tells you to roll the crank '360? Maybe it's assumed..
I got this info from LS1 Tech in a thread. The instructions are called Document ID# 642776 2001 Chevrolet/ Geo Camaro "Valve Rocker Arm and Push Rod Replacement". Looks like a GM instruction sheet.. Does this sound right, or do you have to rotate the motor and torque each valve individually after it's on the base circle per your above instructions? You're not in Michigan by chance are you?? :-)
Exhaust 1,2,7 & 8
Intake 1,3,4 & 5
Rotate Crank 360' then torque the following to 22 ft-lbs
Exhaust 3,4,5 & 6
Intake 2,6,7 & 8
Is this the same order you would do Shane's method? I dont belive in his write up that he tells you to roll the crank '360? Maybe it's assumed..
I got this info from LS1 Tech in a thread. The instructions are called Document ID# 642776 2001 Chevrolet/ Geo Camaro "Valve Rocker Arm and Push Rod Replacement". Looks like a GM instruction sheet.. Does this sound right, or do you have to rotate the motor and torque each valve individually after it's on the base circle per your above instructions? You're not in Michigan by chance are you?? :-)
Now, as far as torquing rocker bolts, they can be open, closed, or somewhere in-between, I have never made sure they are on the base circle when doing the final torque, only when I am counting the turns or attempting to use an adjustable PR to measure proper PR length. Sorry man, I am in TX, that is quite a
08-10-2010, 09:25 PM
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I was only referring to the method of counting the turns to 22 lb-ft. Part of the compression stroke and part of the power stroke, both intake and exhaust are on the base circle, but the intake is 100% on the base circle when the exhaust opens and the exhaust is 100% on the base circle when the intake closes. Those are just easy ways to know for a fact that the lifter is on the base circle. You can double check that with your dad if you like.
Now, as far as torquing rocker bolts, they can be open, closed, or somewhere in-between, I have never made sure they are on the base circle when doing the final torque, only when I am counting the turns or attempting to use an adjustable PR to measure proper PR length. Sorry man, I am in TX, that is quite a
Now, as far as torquing rocker bolts, they can be open, closed, or somewhere in-between, I have never made sure they are on the base circle when doing the final torque, only when I am counting the turns or attempting to use an adjustable PR to measure proper PR length. Sorry man, I am in TX, that is quite a
08-10-2010, 09:31 PM
#16
Texas? Damn!#$&*(.. haha.. Thanks for the info. I will double check with my adjustable push rod checker again using your method to be SURE I am on the base circle.. In your opinion.. Assuming my original p/r checker readings were right, is there a chance in hell that going to a shorter, 7.400 p/r could quite up the clatter? Or do you think I might have some funky lifters causing the clatter? I really want to fix this problem myself, but I am running out of things to try in a hurry! I hate the thought of giving in and taking to a professional to diagnose.. I dont even have a clue in Michigan who builds LS1 motors...???? Thanks again for all your help!
08-10-2010, 09:37 PM
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Stock short block, TSP 5.3 CNC heads (un milled?), stock LS1 lifters, stock MLS head gaskets. Patrick G cam around .230 x.614 lift. I assumed with the smaller base circle of the cam, I would be longer than the 7.400 stock pushrods, but I guess I dont know anything for sure now... Those heads are suppsed to be stock deck height, but who knows.. I called TSP to inquire about my problem and every answer to every question was 'yeah maybe' - I knew after about :30 seconds I was on my own to diagnose..
08-10-2010, 09:42 PM
#18
Stock short block, TSP 5.3 CNC heads (un milled?), stock LS1 lifters, stock MLS head gaskets. Patrick G cam around .230 x.614 lift. I assumed with the smaller base circle of the cam, I would be longer than the 7.400 stock pushrods, but I guess I dont know anything for sure now... Those heads are suppsed to be stock deck height, but who knows.. I called TSP to inquire about my problem and every answer to every question was 'yeah maybe' - I knew after about :30 seconds I was on my own to diagnose..
08-10-2010, 09:57 PM
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Off topic, is it possible to starve the lifters of oil, causing them to be noisy or not pump up? The reason I am asking, is I drilled 1/2" holes in the sides of the lifter trays by each lifter to let some of the oil out.. I read this in a LS1 engine "500HP street engine" building book, and they recommended doing this to limit the trays from completely fiilling up with oil, which would keep the oil from getting too hot and foamy and robbing horse power? Said it was good for a few ponies, so I tried it.. Now Im wondering if it's having adverse effects..
