i just logged my car today and came up with 5deg knock at idle... guessing valvetrain noise as it is audibly loud. my knock goes up ONLY w/ exhaust noise so I am guessing that is all it is for me. I think it is time for me to adjust the RR's the right way (not running, but 90deg turns of crank method). I can hear my valvetrain, what else could this be? I have a video of the noise inside the hood, I will retake the video if need be, i tried to move around so you can hear it from all angles. I am trying to dyno on monday and want 0 knock before I do that.

this file is the video
http://myspacetv.com/index.cfm?fusea...deoid=17625528

this is a freescan log (.csv) of the 3 runs I made today around town.
(Where can I host this file? sorry, dont know where to host files, no website etc, knock is 0 when I am not on the gas, and sometimes when cruising at real low rpms, but really would like to host file so someone can see it)
any advice is appreciated, trying to get it fixed by monday and thinking about re-adjusting rr's first... and making sure the spark plug wire is away from the knock sensor wire.

Has anyone else had the knock that disapears when you get off the throttle? (even at 4000rpms, which is what mine does in "ridetoreese" video)

thanks

 

Also, looking at the datalog, I see that there is 37 deg spark timing at 2150rpms and to me that sounds way high right? The timing does only go up when the knock is 0, and it drops considerably every time the knock goes away so I would really like to get this settled before I dyno.

thanks for the help

 

My car did that. I just tuned the knock sensor out. That was 4 years ago.

 

so how loud is too loud for LT1 valvetrains? It does seem quite loud in person, and a friend who is a 10+ yr mechanic told me the valvetrain is definitly too loud... he is an LS1 guy though so I don't know if it is too loud or just my setup.

I am very close to tuning it out completely, just need to get this tunercat working.

 

do not tune it out yet, you most likely have a problem causing this

try to adjust the valves with the motor running they should sound similar to a sowing machine and make 100% sure you dont have an exhast leak at the manifold(or header)

 

As long as you got forged pistons, just tune it out.

Look at all those 5.0 Mustangs out there, they don't have knock sensors.

 

but do they run around damaging valvetrain due to misadjusted lash

tuning out the knock sensor is only going to make the computer not think there is a problem, its not going to fix the mechanical issue i think your having

 

ya, I have adjusted the RR's at least 8 times since I have built the new motor. I have been having such a crappy time getting them perfect, so I bought new ARP studs (still had stock ones) and I guess I will install those this weekend and readjust the RR's the "correct" way, no more while running. I guess I could redo header gaskets if I am taking out the plugs anyways... looks like fun.

 

My engine has been together over 4 years now with a ton of dragstrip passes without a problem. I am running 12:1 compression, a CC306, and shift at 6800rpm. I have not lifted a valve cover in the same amount of time.

I chased my tail for 6 months trying to figure the excessive KR problems I was having, then I took it to a dyno shop and he had the car for a month and he couldn't figure it out either and refunded my money. The "problem" is the aftermarket valvetrain components making a bunch of friggin' noise. Its to be expected, they are not stock parts.

We tuned it out and my car has been kickin' *** ever since.

I owned 2 5.0s and neither of them had valvetrain problems, EVER.

Good luck

 

And I'll be the one who throws in the silly question. Can you disconnect the KS without tuning it out? What are the pros and cons with this? Again, newbie question but I have to learn somewhere Thanks.

 

The internal noise of your headers will cause retard.

 

No. When you disconnect the knock sensor, it interupts the electrical circuit, and the PCM sets a code. When it sets that code, knock retard will be present almost constantly, ranging up to 15-degrees. The PCM retards timing based on the readings of other sensors, in order to protect the engine.

 

I would not recommend tuning out the KS with stock pistons.

 

I guess I really just need someone with a trained ear to listen to my RR's and valvetrain. I am not sure that it is excessive noise, but a random friend said itw as definitly. He was talking about how on SBC's you do an extra turn after zero lash, and that no SBC would be this loud at idle... well I don't drive a typical SBC, so I am not sure if I should be listening or not to him.

The RR's are not knocking loose like they usually do if they are too loose.

anyone?

 

I've been building race motors for 20 years now and I'll be the first to admit this computer stuff confuses me. With that said, I have found the noise from self aligning rockers to be extremly annoying. Two things you can do to eliminate it. Guide plates and regular roller rockers are much quieter but the best solution are a set of shaft rockers. Dead quiet and more hp. With so many companies making them now you can get a nice set for under $300 that will handle 600hp+. Hope that helps.