Valve train noise video (moved from external genIII)
06-04-2012, 11:04 AM
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Valve train noise video (moved from external genIII) Originally posted in external genIII, but most valve train topics seem to be in here, so I moved it here.
First, I wanted to thank everyone who posted during my pushrod measuring thread. Now that I have them in, I have a sewing machine sound. Its heard inside and varies with RPM. I am willing to try a different length because I have some summit bucks. There is not much insulation on the forward cab and firewall so its obvious.
sewing machine sound heard on the inside. Increases with RPM. Pushrods 7.350 with 1.25 turns from zero lash to 22ft pds. Measured with comp cam tool. 9.25 turns
9.25x .050 = .4625 + 6.8= 7.2656 + .080 (preload)= 7.3425, used 7.350
LQ9 .030 over
L92 heads
ls6 camshaft 204/218 .050/.050
LS3 intake and injectors
longtube headers w/ cats 3" dual dynomax vt mufflers
The noise is heard internally and I dont think I can hear it outside.
idling noise w/ internal noise
Driving noise
http://youtu.be/turQt2PHDw0
First, I wanted to thank everyone who posted during my pushrod measuring thread. Now that I have them in, I have a sewing machine sound. Its heard inside and varies with RPM. I am willing to try a different length because I have some summit bucks. There is not much insulation on the forward cab and firewall so its obvious.
sewing machine sound heard on the inside. Increases with RPM. Pushrods 7.350 with 1.25 turns from zero lash to 22ft pds. Measured with comp cam tool. 9.25 turns
9.25x .050 = .4625 + 6.8= 7.2656 + .080 (preload)= 7.3425, used 7.350
LQ9 .030 over
L92 heads
ls6 camshaft 204/218 .050/.050
LS3 intake and injectors
longtube headers w/ cats 3" dual dynomax vt mufflers
The noise is heard internally and I dont think I can hear it outside.
idling noise w/ internal noise
Driving noise
http://youtu.be/turQt2PHDw0
06-05-2012, 01:19 AM
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almost 100 views and no responses, I got a set of stock length pushrods. I am going to install them and see if it quiet downs. I did what I thought was the right way a few times, but it doesnt seem to be right from the sound of it. Since there stock, their not quite 7.4".
06-05-2012, 03:00 AM
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I don't know, sounds almost normal tome. Video distorts the some. 7.4 sounds a little long maybe. Your math looks good. I have 7.4 length, but my cam is 230/245 duration 630 lift 113 lsa. If i pop my hood the sewing machine sound is loud. Not if i shut my hood though. And I have good insulation. Here's an iidle video, about half way into it, I walk up to the motor, you can hear the sewing machine. Totally normal.
06-05-2012, 05:02 AM
#4
I don't think it sounds bad either. Longer may not be the way to go here. I didn't hear any metal to metal sound. On mine the noise can be heard as well and the FAST intake and headers make it worse as they don't insulate any internal motor sounds at all. Injectors can sometimes be loud as well, have you checked those?
06-05-2012, 12:10 PM
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The sound with the hood open sounds great. Just the interior noise. I cant hear the sewing machine outside. I have been told the lack of insulation with long tube headers can amplify it. I need to pull the seats and add phat mat from the seat area up as high as I can go on the firewall. Again I do appreciate all of the responses. It does not lack in power at all. Being my first LS engine, I think I might be a little paranoid.
I also want to point out I am not doubting any advice that has been given to me.
I also want to point out I am not doubting any advice that has been given to me.
Last edited by mcdonald77; 06-05-2012 at 12:33 PM.
06-05-2012, 01:50 PM
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Thats the catch. I can't hear it on the outside with the hood open. On the inside its the back side of the motor. I think I can hear it slightly while bending down near the fender wells where the LT's pass by.
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06-05-2012, 08:28 PM
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Pushrods 7.350 with 1.25 turns from zero lash to 22ft pds.
9.25 turns for zero lash with the comp cam tool.
9.25x .050 = .4625 + 6.8= 7.2656 + .080 (preload)= 7.3425, used 7.350
with rounding up my actual preload is .087
06-06-2012, 11:30 AM
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today I started it up and pretty much layed on top listening to the valvetrain. I think the problem area might be the 6 or 8 cylinder pushrod or rocker. Ill take some measurements soon. After the install i've only had the drivers side valve cover off.
06-25-2012, 05:32 PM
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did some measuring. Here are my numbers.
Current pushrods 7.35 with 1.25 turns to 22ft pds.
measured at 7.375 with approx 1.60 turns to 22ft pds.
measured at 7.40 with approx 1.80 turns to 22ft pds.
measured at 7.45 with approx 2.375 turns to 22ft pds.
I have a set of stock pushrods I picked up from another member. I am going to install and go from there since those are approx 7.38
Current pushrods 7.35 with 1.25 turns to 22ft pds.
measured at 7.375 with approx 1.60 turns to 22ft pds.
measured at 7.40 with approx 1.80 turns to 22ft pds.
measured at 7.45 with approx 2.375 turns to 22ft pds.
I have a set of stock pushrods I picked up from another member. I am going to install and go from there since those are approx 7.38
Last edited by mcdonald77; 06-26-2012 at 05:35 PM.
06-25-2012, 11:33 PM
#15
To get your most accurate preload measure is to get a magnetic base and a dial indicator. Do like usual and get the lobe for whichever valve you choose on its base circle. Unbolt that rocker. Now take that magnetic base and put where it mounts easiest on the edge of the head. Now get that rocker hand tight. Take the dial indicator that is mounted on your magnetic base and position the tip of it on the oiling hole of the rocker since that's the center of the pushrod. Adjust your dial indicator to whatever you'd like, say .200" and as you torque to spec you should see the number decrease. Say it went to final torque at .120" then you have .80" of preload for that lifter.
Another thing to note which is another way I'd do it if I didn't have a dial indicator or wanted to purchase one. If you have a set of calipers take the adjustable pushrod length where you need it, measure it tip to tip, add the preload, and don't worry about the gauge length crap. I'm fortunate to have a couple speed shops and I can measure the pushrod length on a set. That way I'll see how close the length of the adjustable is compared to a new set. Those are my two ways, I've never trusted the turns theory with that adjustable pushrod. That's just me though.
Hope this helps
Another thing to note which is another way I'd do it if I didn't have a dial indicator or wanted to purchase one. If you have a set of calipers take the adjustable pushrod length where you need it, measure it tip to tip, add the preload, and don't worry about the gauge length crap. I'm fortunate to have a couple speed shops and I can measure the pushrod length on a set. That way I'll see how close the length of the adjustable is compared to a new set. Those are my two ways, I've never trusted the turns theory with that adjustable pushrod. That's just me though.
Hope this helps
06-25-2012, 11:58 PM
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as cams have gotten more aggressive these noises are pretty common and having long tubes tends to act like a megaphone for valvetrain noises too. What are you running for springs ? dual springs will create a sewing machine noise as they compress and the inner and outers rub against each other.
06-26-2012, 09:27 AM
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To get your most accurate preload measure is to get a magnetic base and a dial indicator. Do like usual and get the lobe for whichever valve you choose on its base circle. Unbolt that rocker. Now take that magnetic base and put where it mounts easiest on the edge of the head. Now get that rocker hand tight. Take the dial indicator that is mounted on your magnetic base and position the tip of it on the oiling hole of the rocker since that's the center of the pushrod. Adjust your dial indicator to whatever you'd like, say .200" and as you torque to spec you should see the number decrease. Say it went to final torque at .120" then you have .80" of preload for that lifter.
Another thing to note which is another way I'd do it if I didn't have a dial indicator or wanted to purchase one. If you have a set of calipers take the adjustable pushrod length where you need it, measure it tip to tip, add the preload, and don't worry about the gauge length crap. I'm fortunate to have a couple speed shops and I can measure the pushrod length on a set. That way I'll see how close the length of the adjustable is compared to a new set. Those are my two ways, I've never trusted the turns theory with that adjustable pushrod. That's just me though.
Hope this helps
Another thing to note which is another way I'd do it if I didn't have a dial indicator or wanted to purchase one. If you have a set of calipers take the adjustable pushrod length where you need it, measure it tip to tip, add the preload, and don't worry about the gauge length crap. I'm fortunate to have a couple speed shops and I can measure the pushrod length on a set. That way I'll see how close the length of the adjustable is compared to a new set. Those are my two ways, I've never trusted the turns theory with that adjustable pushrod. That's just me though.
Hope this helps
as cams have gotten more aggressive these noises are pretty common and having long tubes tends to act like a megaphone for valvetrain noises too. What are you running for springs ? dual springs will create a sewing machine noise as they compress and the inner and outers rub against each other.
06-27-2012, 10:16 AM
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Im starting to sway this way, but I want to be absolutely sure there is no problem before I put it on a dyno run it up to 6500rpm. I think its obviously close since i've been over 1000 miles and no damage.
06-27-2012, 05:47 PM
#20
IMO, that sewing machine sound is as much from loaded needle bearings in the rockers than noise from the springs. Again IMO, when dual heavy springs are noted as the issue, those heavy dual springs are putting a higher load on the needle bearings & they become louder than when less loaded.