Sewing Machine????
 

I have my enging back together and running. But it sounds like a damn sewing maching. At an idle and gets worse with RPM. I'm getting tired if driving arround with my window up and the radio on!!!

The motor is a standard bore with a 3.900 stroke (eagle rods and pistons, JE pistons) CnC ported LS6 heads. Comp cam kit (224/230@.050 .581/.588 114*)
lifters and pushrods. Scorpion Rockers. Supermaxx headers and a SLP LM2.

The machinist used 7.400 pushrods when he put the motor together. I science put in some 7.425 to see if it would quiet it up. Its better but not satisfactory.

Ive let people listen to it and I get responces that its normal , bent pushrods and one guy told me that Comp had some problems with their lifters.

Im taking the car in to Speed Inc. Fri for a dyno tune. hopefully they will have an answer.

What should I do? Anyone find a cure for this? At this point I dont care how much it costs.

Its embarassing bragging to your friends all summer long about your badass car your building and put 15,000.00 in and when I show it off they ask why it sounds like shit and have that goofy look on their face.


Thanks for any help in this matter.

Greg


P.S.

Its not an exhaust leak.

Maybe exhaust leak at the headers? Id start looking outside the valvetrain as well.

Depending on how big you go with the cam, and how aggresive the lobes are, you're going to have the sewing machine noise.

I'm running a 233/239 .595/.603 and mine does it all the time. It's just something you deal with when running cams with aggressive lobes. Kind of like changing the valve springs every 15-20k.

What kind of oil are you running. Some of the synthetic oils run alot quiter.

I do not quite agree with that. Excessive valvetrain noise is due to mismatched components (mostly to improper preload on lifters).
I have a 232/234 XE-R and no noise at all. I played with mill and gasket to reach proper preload on the p-rods I wanted to run.
i'm running 7.400 and my heads are milled .025' and gasket is .050.
You can actualy hear the injectors pulsing :jest:

I find that somewhat hard to believe....

Back on topic....

Meant to be a joke :eyes:

Sorry...didn't realize that...

Predator-Z,

What kind of lifters are you using?

Normal on h/c cars. cars that come from Cartek, ECS and Vette doctors all do the same thing.

Comes from a combination of things like stiffer valve springs, high ramp rate cams, etc.

Mine is a little noisy but my tuner says it's normal, and he's seen many, many cars like mine. Nevertheless, I have a set of 7.375" PR's that I may try out. These would move my preload up to 0.100". We'll see what happens.

Comp 850-16

I noticed the same with my car. My cam makes the valve train chatter. Its typical for a big cam.

I have 224-230 114lsa xer in my car too with crane adjustable rocker arms, stock GM lifters and proper geometry and preload and it sounds like a sewing machine only when hot. 5w50 synthetic helped a lot but I think it's normal for the LS1. Performance is good so I don't care about the sound. It can be annoying at the traffic lights when people look at my car and seem to wonder what's going on under the hood. It's like an exhaust leak but I checked everything including plugs and still the same tick :bang: My sewing machine sound is only below 1200 rpm though.

SSDION

I guess i'll throw in my $.02. My set up (see sig) was quiet after I got it back from LPE (21st CMC) but after my first oil change using mobil 1 5w-30 it got that real loud annoying sewing machine sound. I called 21st CMC and they informed me that they used 15w50 mobil 1 when they did my h/c pacakge. I changed the oil again the next day and after a short run and letting the 15w-50 circulate it quieted down. Now it's not even noticeable. FWIW I have about 3500 miles on this set up and no problems so far. HTH

Hey man, don't forget to post what it dyno's on Friday. I'm curious to see.

Ben T.

Singer here. :jest:
You kids, I swear! Why, back in the day, a rumpy dump idle and noisy valvetrain was a thing of beauty. Meant you were da shit and challenger beware. I love the sound. And those that know cars recognize that sound.
Come on fellas! Be proud of what you have.......and quit bitching like little high school girls on the rag. :devil: J/K

I think many setups out there don't have the correct preload and are making what should be some valvetrain noise into a lot of clatter.

The simple approach I think is to carefully check your preload. If 7.425s made it better it's probably a good bet that your preload is wrong. Get it between .060 and .100 and I think you'll see a big difference.

:lol: :lol: :lol:

lol but those old cars ran solid lifters. We all have hydraulic and those should be a little quieter.