Help me avoid the sewing machine sound
10-24-2007, 08:41 AM
#1
Staging Lane
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Help me avoid the sewing machine sound I'm planning a cam swap, but I don't want my car to sound like a sewing machine. I've done alot of searching but there doesn't seem to be any consensus on what causes it. Some have said it's the stock rockers, others say it's improper lifter preload, and still others say it's aggressive ramp rates like the Xe-r lobes and yadda, yadda, yadda. So which one is it? Is it a combination of factors? I'm looking to install the Trickflow Stage III cam which is ground by Lunati and eventually get the TFS heads which means i'll be getting new rockers. Will this head/cam package make less noise since i've elimanated two of the possible factors. Thanks for any help.
10-24-2007, 08:45 AM
#2
Good luck. It's almost impossible to not have a sewing machine noise after upgrading valvetrain. It's just the nature of the beast & something you'll have to deal with if you plan on modding.
The best way to decrease this noise is to make 100% sure your part are matched perfectly & not just thrown together. You'll never eliminate it completely.
And unless they are offering a special deal on those heads, they will not come with new rockers. You'll either have to send in a set of stockers to Harland Sharp to be rebuilt or pay for some aftermarket ones.
The best way to decrease this noise is to make 100% sure your part are matched perfectly & not just thrown together. You'll never eliminate it completely.
And unless they are offering a special deal on those heads, they will not come with new rockers. You'll either have to send in a set of stockers to Harland Sharp to be rebuilt or pay for some aftermarket ones.
10-24-2007, 09:06 AM
#4
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I think stock cams sound like sewing machines! LOL. Well, most people dont like this idea, but I put an LS6 cam(and heads) in my LS1 and the valvetrain noise isnt much louder...With EVERYTHING else stock(including airbox n exhaust) the car runs 12.5's on the stock tires! 19MPG's round town, and 25+ MPG's highway....
-Dan
-Dan
10-24-2007, 09:21 AM
#5
The sewing machine sound you're referring to is caused by the aggressive lobe profiles of most aftermarket cam designs. What you're actually hearing is the valve slamming shut on the valve seat with the aftermarket cam instead of being "gently" closed with the stock cam. It's got very little to do with pushrods, springs or rockers. If you don't like the sound, buy a camshaft with less aggressive lobes that set the valves down easier, and get a louder exhaust to cover up some of the sound.
10-24-2007, 09:56 AM
#7
I think stock cams sound like sewing machines! LOL. Well, most people dont like this idea, but I put an LS6 cam(and heads) in my LS1 and the valvetrain noise isnt much louder...With EVERYTHING else stock(including airbox n exhaust) the car runs 12.5's on the stock tires! 19MPG's round town, and 25+ MPG's highway....
-Dan
-Dan
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10-24-2007, 10:09 AM
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I had Yella Terra rockers with my Tqr V3 and thought I might be giving up some power because of the heavier rocker (I have the old style), so I switched back to the stock rockers. The noise was almost unnoticeable with the YT's and is very noticeable/ borderline loud with the stockers. Aftermarket rockers do help, but you will still have the noise.
10-24-2007, 11:19 AM
#11
Now back on topic.
If it is the stock rockers making the noise the new bearings & stuff they do to them at Harland Sharp when they rebuild them could help eliminate some of the noise.
10-24-2007, 11:46 AM
#14
I believe Harland Sharp only charges $225 plus shipping both ways & thats cheaper than a set of aftermarket rockers.
10-24-2007, 10:52 PM
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Good luck. It's almost impossible to not have a sewing machine noise after upgrading valvetrain. It's just the nature of the beast & something you'll have to deal with if you plan on modding.
The best way to decrease this noise is to make 100% sure your part are matched perfectly & not just thrown together. You'll never eliminate it completely.
And unless they are offering a special deal on those heads, they will not come with new rockers. You'll either have to send in a set of stockers to Harland Sharp to be rebuilt or pay for some aftermarket ones.
The best way to decrease this noise is to make 100% sure your part are matched perfectly & not just thrown together. You'll never eliminate it completely.
And unless they are offering a special deal on those heads, they will not come with new rockers. You'll either have to send in a set of stockers to Harland Sharp to be rebuilt or pay for some aftermarket ones.
10-24-2007, 10:59 PM
#17
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I had Yella Terra rockers with my Tqr V3 and thought I might be giving up some power because of the heavier rocker (I have the old style), so I switched back to the stock rockers. The noise was almost unnoticeable with the YT's and is very noticeable/ borderline loud with the stockers. Aftermarket rockers do help, but you will still have the noise.
10-24-2007, 11:02 PM
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Mine is actually very quiet other than a loud ticking during warm up that lasts for maybe 2 minutes. Other than that I hear no valvetrain nose inside the car. Personally, I think pushrod length is the culprit more often than not. I have factory rockers btw. The valvetrain in my Camaro with mods below is quieter than my factory 04 Silverado.
10-24-2007, 11:06 PM
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The sewing machine sound you're referring to is caused by the aggressive lobe profiles of most aftermarket cam designs. What you're actually hearing is the valve slamming shut on the valve seat with the aftermarket cam instead of being "gently" closed with the stock cam. It's got very little to do with pushrods, springs or rockers. If you don't like the sound, buy a camshaft with less aggressive lobes that set the valves down easier, and get a louder exhaust to cover up some of the sound.
