Large cam, valve train noise
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Teching In
Joined: Mar 2011
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Large cam, valve train noise Ive read a lot about this subject, Im on the fence..is it normal,is this the price to pay for high ramp cam rates? Or is this simply incorrect set up?
Ive read both...sewing machine theory and everything else..
So now like many others I ask you.
heres a short clip of my "cam noise" tell me what you think. thanks!
Just bought this car, Im unfamiliar with the build and builder...it is the hawks sinister 450rwhp h/c/I kit. (sisnister cam)..kit comes with 7.400 hardened push rods, Im worried the cam base is not the same has a stock cam, causing all the noise. Ive read every set up is a bit different depending on the heads, headgasket thickness, and cam base, Ive read the 7.400 will not be correct for these custom set ups..Is it time to check push rod length on this motor?
Ive read both...sewing machine theory and everything else..
So now like many others I ask you.
heres a short clip of my "cam noise" tell me what you think. thanks!
Just bought this car, Im unfamiliar with the build and builder...it is the hawks sinister 450rwhp h/c/I kit. (sisnister cam)..kit comes with 7.400 hardened push rods, Im worried the cam base is not the same has a stock cam, causing all the noise. Ive read every set up is a bit different depending on the heads, headgasket thickness, and cam base, Ive read the 7.400 will not be correct for these custom set ups..Is it time to check push rod length on this motor?
It does sound a little loud but I can't really tell for sure from the video sound.
So yes play it safe and check for proper PR length with a pushrod length checker, but you'll also need to know what lifters are in your engine so you'll be able to know what the preload range is and then you can determine the ideal PR length.
So yes play it safe and check for proper PR length with a pushrod length checker, but you'll also need to know what lifters are in your engine so you'll be able to know what the preload range is and then you can determine the ideal PR length.
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Joined: Aug 2004
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From: Auckland, Nth Is, New Zealand.
Not the quietest is it! Highly unlikely 7.400 push rods are the right length.
Don't forget that aggressive cam rates will also make the tapping sound from the valves slamming shut.
Don't forget that aggressive cam rates will also make the tapping sound from the valves slamming shut.
Once heads and headgaskets are changed all pushrod measurments go out the window and needs to be measured.
Sure you can get away with a 7.4 pushrod when just doing the cam, but when you change the top end also it's a whole nother animal.
Sure you can get away with a 7.4 pushrod when just doing the cam, but when you change the top end also it's a whole nother animal.
Thread Starter
Teching In
Joined: Mar 2011
Posts: 18
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Yea, when I found out this car had the hawks sinister package and read the kit details, I thought to myself the 7.400 push rods it came with was not correct length for a custom set up.
I thank you for the reassurance on my thoughts.
Im will run a push rod length checker and go from there.
And gary, idk how many miles are on this build for sure..I was told about 3000..Ive put 1000 on it since ive owned it..
here another quik video I just did in attempt to capture better sound, thanks for all the replys!
https://www.youtube.com/watch?v=Kf4r...ature=youtu.be
I thank you for the reassurance on my thoughts.
Im will run a push rod length checker and go from there.
And gary, idk how many miles are on this build for sure..I was told about 3000..Ive put 1000 on it since ive owned it..
here another quik video I just did in attempt to capture better sound, thanks for all the replys!
https://www.youtube.com/watch?v=Kf4r...ature=youtu.be
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i think that noise is the valves echoing thru the fast 102, i got that same noise after i installed mine from a ls6 intake . i actually pulled it back off thinking something fell in.. not saying its normal but try searching for it i think i found a couple people with same noise . and fyi mine has been to 7k a few times .
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Teching In
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i think that noise is the valves echoing thru the fast 102, I got that same noise after i installed mine from a ls6 intake . i actually pulled it back off thinking something fell in.. not saying its normal but try searching for it i think i found a couple people with same noise . and fyi mine has been to 7k a few times .
and yes mine has hit 7k a few times too, it hauls ***! lol.
It doesn't sound as bad as some I have heard, but what we've been finding a lot is that it's the lifters bleeding down and then pumping back up that can cause the majority of most people's issues when it comes to valve train noise.
I've seen guys change push rod length 3-4 times in an attempt to quieten down the valve train. Only to swap lifters later on down the road and they find the noise is now alleviated.
Some stock lifters emit this ticking noise while others don't. I believe this to be from the tolerances being too loose. It's fine for stock applications, but add 150psi of seat pressure and 380-420psi of open spring pressure into the mix and you get what you see(or hear) here.
Does this kit they sell come with new lifters or aftermarket lifters?
I've seen guys change push rod length 3-4 times in an attempt to quieten down the valve train. Only to swap lifters later on down the road and they find the noise is now alleviated.
Some stock lifters emit this ticking noise while others don't. I believe this to be from the tolerances being too loose. It's fine for stock applications, but add 150psi of seat pressure and 380-420psi of open spring pressure into the mix and you get what you see(or hear) here.
Does this kit they sell come with new lifters or aftermarket lifters?
I think you all get too worked up over exact pushrod length. If its in the range, should be good. I to have heard from guys who have been through several sets trying to find the perfect preload, no change in the noise.
Agree 100% with the FAST 102 amplifying the noise! Try this. Wet a big towel and lay it on the manifold while it's running. I have one on my Vette (the intake, not a towel) and it acts like a speaker.
If it has roller rockers, they add noise too! I had to replace my YT's with the new version. Valves got quieter.
I agree with the lifter theory. But the ramp rate figures in as well.
I have 2 LS engines. The Vette is an EPS grind done by comp. It's loud.
Martins turbo cam in my Nova, with stock rockers (trunion upgrade) is very quiet. Amazingly quiet in fact. Both have LS7 lifters. Both set up with .060" preload.
Ron
Agree 100% with the FAST 102 amplifying the noise! Try this. Wet a big towel and lay it on the manifold while it's running. I have one on my Vette (the intake, not a towel) and it acts like a speaker.
If it has roller rockers, they add noise too! I had to replace my YT's with the new version. Valves got quieter.
I agree with the lifter theory. But the ramp rate figures in as well.
I have 2 LS engines. The Vette is an EPS grind done by comp. It's loud.
Martins turbo cam in my Nova, with stock rockers (trunion upgrade) is very quiet. Amazingly quiet in fact. Both have LS7 lifters. Both set up with .060" preload.
Ron
Thread Starter
Teching In
Joined: Mar 2011
Posts: 18
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Thank you for all the replys I really appreciate it!
Under a stethoscope it sounds super smooth, the loudest component is the injectors.
Maybe the 102 intake is amplifying them.
Under a stethoscope it sounds super smooth, the loudest component is the injectors.
Maybe the 102 intake is amplifying them.
Last edited by Black 97 WS6; Jun 1, 2014 at 05:07 PM.
