luv2spd

iTrader: (1)

By "more aggressive lobe design" I mean the ramp rates. In other words, the more aggessive the ramp rate, the faster the valve is opened and slammed shut;thus, more noise.

Droptopws6

iTrader: (13)

I dont understand the "sewing machine sound" my valve train sounds stock. Im thinking that something is wrong if your having a noisy valve train. I dunno

Predator

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!!

jason5

iTrader: (2)

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

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.

Droptopws6

iTrader: (13)

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

BBQLS1

Cool.

BBQLS1

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.

Droptopws6

iTrader: (13)

Listen to my video do you hear it? Maybe the audio quality isnt good enough anyway let me know if my car is making the same noise your hearing, thx

Predator

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.

zamboxl

iTrader: (1)

yea mine is the loudest from 1k rpm to 2k of curse that is partly due to a badly seated valve seat but is still making the lifter noise at that engine speed.

Droptopws6

iTrader: (13)

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.

ChiTownSS

He said it's coming from under the car...leaking header gasket?

TheBlurLS1

iTrader: (8)

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.

JCMGTO

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.

CamTom12

iTrader: (1)

I hear it some days and don't others... My cam's only 222 @.566 112LSA

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

luv2spd

iTrader: (1)

Its true. When I put on my LTs w/ the stock cam I could hear more valvetrain noise through the headers, especially down by the collector area. I think the thin walls of the headers compared to the thick cast manifolds is the main reason for it getting louder.

Zinc

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

MGorman

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.