what causes the sewing machine sound with cams
Originally Posted by Predator
That's interesting, I have the 224 112 with 918s and it definitely makes the sewing machine sounds, but I didn't know that the TR224 had a more "aggressive lobe design." Could you explain exactly what that means?
Thanks.
Thanks.
TECH Addict
Joined: Jun 2002
Posts: 2,428
Likes: 0
From: Las Vegas, NV
Thanks luv2spd, you learn something new all the time.
The sewing machine valvetrain sounds makes me think, when I hear it, that the springs, rocker arms, pushrods, and valves are just moving more precisely, with no slop, but Droptopw26 seems to blow a hole in my theory. How do you explain his being quiet? Weird!!
The sewing machine valvetrain sounds makes me think, when I hear it, that the springs, rocker arms, pushrods, and valves are just moving more precisely, with no slop, but Droptopw26 seems to blow a hole in my theory. How do you explain his being quiet? Weird!!
yeah i dont understand why most people say they have it, and then others who have the same setup say theirs is just like stock, it does't make sense, it must not be a problem because i have driven the car for 6 months and haven't had a problem out of it yet
TECH Addict
Joined: Jun 2002
Posts: 2,428
Likes: 0
From: Las Vegas, NV
I forgot to mention the lifters, but maybe (thinking about this) the type of exhaust system you're running is a factor in how loud the valvetrain is. Maybe a less restrictive exhaust translates to less valvetrain noise. I see that Droptop has an ORP and no cats (I assume), and I have shorty headers (we all make mistakes), and hi-flo cats, more restrictive and more valvetrain noise. I dunno know really.
Yeah I know its weird, I would be freaked out if I had lifter noise. To tell ya the truth I would have tore it back down and retorqued the rockers. Yes your right I have no cats also, hell I dunno
TECH Enthusiast
Joined: Nov 2004
Posts: 659
Likes: 0
From: Red Stick, LA
Originally Posted by SSOnYourSix
we did a set of comp OE replacement lifters on an X3 car and it made the lifter noise noticably quieter vs the cars we usually do the cams in that use stock lifters...
TECH Enthusiast
Joined: Nov 2004
Posts: 659
Likes: 0
From: Red Stick, LA
I don't think everyone "hears" the sewing machine noise. Some peoples ears are better tunned I guess. Lots of people get supprised at the noises I hear over the radio and exhaust and highway noise, and they don't hear it. But it's there.
Maybe is just noises in my head.
Maybe is just noises in my head.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo TECH Addict
Joined: Jun 2002
Posts: 2,428
Likes: 0
From: Las Vegas, NV
Hey Droptop, it's pretty hard to tell from that video (it does sound sweet though) because all you can really hear is the exhaust. I hear mine the best when the hood is open, or even just listening standing near the hood.
Originally Posted by luv2spd
Does anyone else think its most pronounced at like 2000 rpms? I think mine is the loudest around this area....something with the harmonics.
I can honestly say that after I changed the cam and springs I heard no difference. Did you guys torque the rockers and then tun the motor over (by hand) and retorque or recheck? There has to be something to this.
i have comp 850 lifters, PRC dual springs, and a stock cam in my car, if you get down behind the driver side front tire and listen, you can hear all kinda **** going down LOL.
i'm putting a 230+ cam in it this summer w/ new oilpump/timingchain/pulley and we will see how it does. i'm blaming my noise on the big *** springs and hoping for the best.
i'm putting a 230+ cam in it this summer w/ new oilpump/timingchain/pulley and we will see how it does. i'm blaming my noise on the big *** springs and hoping for the best.
Teching In
Joined: Jan 2005
Posts: 28
Likes: 0
From: Doylestown,PA
I just did a Comp Cams XER273 with AFR 205's with dual springs and I have the noise. Up top the motor sounds quite get next to the wheel well and I get the I guess sewing machine. It is loudest by the collectors. I think because it is going down the exhaust and the headers are magnifing it. The ones who don't hear it do you have headers? and what type? I know it is probably natural but it drives me crazy at first, especially since I just finished the build. I had a cam in my 2000 GTX(GTP) that did the same thing. I'll double check rockers and lash though. Maybe with the dual springs it messed up TQ on the rockers.
Launching!
Joined: Jan 2002
Posts: 224
Likes: 0
From: Monticello, MN
Originally Posted by Predator
I forgot to mention the lifters, but maybe (thinking about this) the type of exhaust system you're running is a factor in how loud the valvetrain is. Maybe a less restrictive exhaust translates to less valvetrain noise. I see that Droptop has an ORP and no cats (I assume), and I have shorty headers (we all make mistakes), and hi-flo cats, more restrictive and more valvetrain noise. I dunno know really.
I have read that longtube headers magnify, and provide a sound path for, valve train noise. I'm about to find out. I hope it doesn't.
Ed
Originally Posted by C5XTASY
I have read that longtube headers magnify, and provide a sound path for, valve train noise. I'm about to find out. I hope it doesn't.
Ed
Ed
On The Tree
Joined: Jan 2005
Posts: 107
Likes: 0
From: Minneapolis
I'll let you guys know if I hear it today. Im starting the car up for the 1st time since the cam went in, so Im sure I'll hear "the noise" if its there.
Info on car:
'98 Z28
Mac mid headers
Rollmaster double roller
LS6 pump
FM11 228/230
Stock catback w/ cutout (ill try it w/ the cutout open and with it closed to see If I can hear a diffrence in valvetrain noise [if there is any at all])
Ryan
Info on car:
'98 Z28
Mac mid headers
Rollmaster double roller
LS6 pump
FM11 228/230
Stock catback w/ cutout (ill try it w/ the cutout open and with it closed to see If I can hear a diffrence in valvetrain noise [if there is any at all])
Ryan
On The Tree
Joined: Mar 2005
Posts: 157
Likes: 0
From: Pasadena, MD
I’ve got AFR heads the Comp 921 springs and a Comp 224/228 581/588 cam. The valve train noise is LOUD. Everything is put together right. That’s just the way it is.
There’s no missing this noise, even people that know nothing about cars notice it.
PS I had headers on the car before the heads and cam were installed. With the stock cam and valve springs I had little to no valve train noise.
There’s no missing this noise, even people that know nothing about cars notice it.
PS I had headers on the car before the heads and cam were installed. With the stock cam and valve springs I had little to no valve train noise.