LS Valve Train Noise Sucks! I challenge the aftermarket.
09-21-2011, 09:57 PM
#1
LS Valve Train Noise Sucks! I challenge the aftermarket. All this excessive valve train noise on LS engines hydraulic rollers suck. Somebody needs to produce a lobe, lifter or combination of the two that is quiet. It is literally the only downside to the LS engine that I know of. I have no idea why there is not more attention paid to this issue.
Who is going to step up?
Who is going to step up?
09-21-2011, 10:12 PM
#3
TECH Senior Member
I've ran XER, XFI, XE and found quiet valvetrain by paying attention to details.
1- Correct preload
2- Correct spring
3- Correct spring height
So all this "sewing machine" BS is just improper install IMO.
Why, because the majority of enthusiasts just slap the combo together and do not follow correct procedures.
1- Correct preload
2- Correct spring
3- Correct spring height
So all this "sewing machine" BS is just improper install IMO.
Why, because the majority of enthusiasts just slap the combo together and do not follow correct procedures.
09-21-2011, 10:18 PM
#4
You want to be a Speedtigger or a Speedpussycat because unfortunately the noise is created from the very same situation the enables you to make more power 
It's the aggressiveness of the lobe profiles quickly lifting the valve off the seat....holding it close to peak lift as long as possible (where your heads are moving the most air typically), and then quickly dropping the valve back on the seat to keep the duration (seat timing) reasonable.
Its literally the faster valve motion your actually hearing, the meeting of the valve and the valve seat amplified by the header tube which almost acts as a bell making the noise even worse.
Now, some lobes are have slower profiles/ramp rates but wont make as much power....if your looking for the most performance it comes at the expense of some valvetrain noise but some folks have more than they should due to improper valvetrain selection and set-up.
Anyway...hope this clears up the "sewing machine" noise issue or should I say helps you better understand it.
If you ran an older design XE lobe (especially with a pair of cast iron exhaust manifolds) you wouldn't have nearly as much noise as the more common XER and LSL lobes with long tube headers but you wouldn't make as much power either.....thats the long and short of the situation.
-Tony
It's the aggressiveness of the lobe profiles quickly lifting the valve off the seat....holding it close to peak lift as long as possible (where your heads are moving the most air typically), and then quickly dropping the valve back on the seat to keep the duration (seat timing) reasonable.
Its literally the faster valve motion your actually hearing, the meeting of the valve and the valve seat amplified by the header tube which almost acts as a bell making the noise even worse.
Now, some lobes are have slower profiles/ramp rates but wont make as much power....if your looking for the most performance it comes at the expense of some valvetrain noise but some folks have more than they should due to improper valvetrain selection and set-up.
Anyway...hope this clears up the "sewing machine" noise issue or should I say helps you better understand it.
If you ran an older design XE lobe (especially with a pair of cast iron exhaust manifolds) you wouldn't have nearly as much noise as the more common XER and LSL lobes with long tube headers but you wouldn't make as much power either.....thats the long and short of the situation.
-Tony
09-21-2011, 10:20 PM
#5
Some people, like myself, are very annoyed by it, while others just accept it as normal.
09-21-2011, 10:21 PM
#6
09-21-2011, 10:24 PM
#7
TECH Senior Member
Originally Posted by speedtigger
I don't think this is true. Too many people are complaining and all of the cam manufacturers and specialty shops acknowledge it. I know mine is right and it is louder by far than the old solid flat tappets that we used to run.
Some people, like myself, are very annoyed by it, while others just accept it as normal.
Some people, like myself, are very annoyed by it, while others just accept it as normal.
What install steps did you take?
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09-21-2011, 10:29 PM
#8
You want to be a Speedtigger or a Speedpussycat because unfortunately the noise is created from the very same situation the enables you to make more power
It's the aggressiveness of the lobe profiles quickly lifting the valve off the seat....holding it close to peak lift as long as possible (where your heads are moving the most air typically), and then quickly dropping the valve back on the seat to keep the duration (seat timing) reasonable.
Its literally the faster valve motion your actually hearing, the meeting of the valve and the valve seat amplified by the header tube which almost acts as a bell making the noise even worse.
Now, some lobes are have slower profiles/ramp rates but wont make as much power....if your looking for the most performance it comes at the expense of some valvetrain noise but some folks have more than they should due to improper valvetrain selection and set-up.
Anyway...hope this clears up the "sewing machine" noise issue or should I say helps you better understand it.
If you ran an older design XE lobe with a cast iron exhaust manifold you wouldn't nearly have as much noise as the more common XER and LSL lobes but you wouldn't make as much power either.....thats the long and short of the situation.
-Tony
It's the aggressiveness of the lobe profiles quickly lifting the valve off the seat....holding it close to peak lift as long as possible (where your heads are moving the most air typically), and then quickly dropping the valve back on the seat to keep the duration (seat timing) reasonable.
Its literally the faster valve motion your actually hearing, the meeting of the valve and the valve seat amplified by the header tube which almost acts as a bell making the noise even worse.
Now, some lobes are have slower profiles/ramp rates but wont make as much power....if your looking for the most performance it comes at the expense of some valvetrain noise but some folks have more than they should due to improper valvetrain selection and set-up.
Anyway...hope this clears up the "sewing machine" noise issue or should I say helps you better understand it.
If you ran an older design XE lobe with a cast iron exhaust manifold you wouldn't nearly have as much noise as the more common XER and LSL lobes but you wouldn't make as much power either.....thats the long and short of the situation.
-Tony
I have to think that if there was more pressure for a quieter performance lobe, the effort to find a solution would be much greater. I really wonder if a solid roller would not be quieter than the hydraulic I have right now, and it is not even and aggressive lobe.
Do I want my cake and eat it too? Hell yes! Now it is time for someone with a solution to step up and give it to the LS community.
09-21-2011, 10:32 PM
#9
Certain materials used in engine parts can eminate sound with intensity.
Back in the mid ninties I had a 434 sbc drag engine that was hard blocked
up to the waterpump holes...and man did that thing have incredibly loud
rotating assembly noise...especially on cold startup. I also ran a 2bbl street-
stock engine w/338 gram slugs on 6" rods and that thing revved stoopid quick
but sounded like 8 rod knocks on cold startup. With regards to the LS engine
it's my opinion that the absurd density of the light but strong rocker arm
tends to radiate noise (sewing machine) and all us 600 lift cam and high
spring pressure freaks only put the poor rocker through even more hell than it
was originally designed for. Most don't know that @ 7000 rpms each valve is
opening AND closing like 58 times/sec.
Back in the mid ninties I had a 434 sbc drag engine that was hard blocked
up to the waterpump holes...and man did that thing have incredibly loud
rotating assembly noise...especially on cold startup. I also ran a 2bbl street-
stock engine w/338 gram slugs on 6" rods and that thing revved stoopid quick
but sounded like 8 rod knocks on cold startup. With regards to the LS engine
it's my opinion that the absurd density of the light but strong rocker arm
tends to radiate noise (sewing machine) and all us 600 lift cam and high
spring pressure freaks only put the poor rocker through even more hell than it
was originally designed for. Most don't know that @ 7000 rpms each valve is
opening AND closing like 58 times/sec.
09-21-2011, 10:43 PM
#11
Junk Yard LQ9 55k miles.
Texas Speed Stage 1 LS6 heads with Pac 1518 springs factory installed height.
LS7 lifters
Comp Cams XR275HR12 (222/224 .566/.568)
I have tried every hardened pushrod from 7.325 to 7.4.
They all sound exactly the same.
The current lifter preload is .087" verified with the Comp pushrod checker and a dial indicator.
The engine idles at just over 30 pounds of oil pressure at 700 rpm and quickly goes above 50 pounds at a cruise and over 75 lbs at upper RPM.
This lifters are quietest when the car is cold. Slightly thicker oil, makes them slightly quieter. They are the noisiest at about 1500 rpm. The sound is exactly like everyone describes. Sewing machine.
It made this same noise with a lifters that came with the motor, so I pulled them out and put in the LS7 lifters. It seemed quieter at first, but once the motor got up to temp it was back.
To give you my level of technical experience, I have been doing this for 23 years. I have done everything from grinding crankshafts to building chassis. I was degreeing cams when most of the guys on this forum were still crapping their pants.
If you guys can lead me to the path of quieting this valve train, I will be the most appreciative guy you could imagine.
Last edited by speedtigger; 09-21-2011 at 10:51 PM. Reason: added cam info
09-21-2011, 11:00 PM
#14
TECH Senior Member
I will lay it out for you as it went.
Junk Yard LQ9 55k miles.
Texas Speed Stage 1 LS6 heads with Pac 1518 springs factory installed height.
LS7 lifters
Comp Cams XR275HR12 (222/224 .566/.568)
I have tried every hardened pushrod from 7.325 to 7.4.
They all sound exactly the same.
The current lifter preload is .087" verified with the Comp pushrod checker and a dial indicator.
The engine idles at just over 30 pounds of oil pressure at 700 rpm and quickly goes above 50 pounds at a cruise and over 75 lbs at upper RPM.
This lifters are quietest when the car is cold. Slightly thicker oil, makes them slightly quieter. They are the noisiest at about 1500 rpm. The sound is exactly like everyone describes. Sewing machine.
It made this same noise with a lifters that came with the motor, so I pulled them out and put in the LS7 lifters. It seemed quieter at first, but once the motor got up to temp it was back.
To give you my level of technical experience, I have been doing this for 23 years. I have done everything from grinding crankshafts to building chassis. I was degreeing cams when most of the guys on this forum were still crapping their pants.
If you guys can lead me to the path of quieting this valve train, I will be the most appreciative guy you could imagine.
Junk Yard LQ9 55k miles.
Texas Speed Stage 1 LS6 heads with Pac 1518 springs factory installed height.
LS7 lifters
Comp Cams XR275HR12 (222/224 .566/.568)
I have tried every hardened pushrod from 7.325 to 7.4.
They all sound exactly the same.
The current lifter preload is .087" verified with the Comp pushrod checker and a dial indicator.
The engine idles at just over 30 pounds of oil pressure at 700 rpm and quickly goes above 50 pounds at a cruise and over 75 lbs at upper RPM.
This lifters are quietest when the car is cold. Slightly thicker oil, makes them slightly quieter. They are the noisiest at about 1500 rpm. The sound is exactly like everyone describes. Sewing machine.
It made this same noise with a lifters that came with the motor, so I pulled them out and put in the LS7 lifters. It seemed quieter at first, but once the motor got up to temp it was back.
To give you my level of technical experience, I have been doing this for 23 years. I have done everything from grinding crankshafts to building chassis. I was degreeing cams when most of the guys on this forum were still crapping their pants.
If you guys can lead me to the path of quieting this valve train, I will be the most appreciative guy you could imagine.
09-21-2011, 11:11 PM
#15
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THis^^^. Yes you hear about it alot because most cam kit vendors sell people 7.4" pushrods when it has been proven by guys on here with 100's of camshaft installs in these cars that you should have a 7.425" pushrod with stock heads/gasket and aftermarket cam. That is why you see it so much. That and improper installation. I have tons of friends with cam/heads ls1's and have heard them with the hood popped. Sounds quiet to me...
09-22-2011, 12:40 AM
#16
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Also, to add, my engines have always had LTs, and I have run single and double springs, along with 100k stock lifters, and LS7 lifters. So I have seen quite a few variations of parts. First cam was with a stock engine and 7.425 PRs. After that I have always measured using Shane at TR method of turns. Always ended up with 1 1/2 to 1 3/4 turn of the rocker bolt past zero lash.
Last edited by 01ssreda4; 09-22-2011 at 08:11 AM.
