Anynone using 7.450 push rods with a 224/224 .567/.567 LSA114 cam o quieten the sewing machine sound?
Thx,

 

Have you already tried the CompCams 7.425??? I did, and it did lower the sewing-machine noise...

 

7.45 is kinda long, like Mr. nice avatar above me stated I think the 7.425 would be a better choice.

 

Yes I have 7.425 push rods in it now and still get the loud sewing machine sound.
Thx
Sleeper

 

That's the size in there now...and the sewing machine sound is louder than others with a larger lift and duration than I have...

 

How about getting a pushrod length checker instead of guessing? They're only like 20 bucks. What cam are you running? Are your heads milled? What springs and lifters? Maybe you're going the wrong way and you need shorter pushrods?

 

The bottom line is, how many turns to 22ft/lbs. after zero lash? If you're more than one full turn (and I don't care what GM says), you've got the wrong size.

Arnel

 

hmmm...put 7.300's in my recently cammed ls1...comp's xr275hr cam (224 dur. .568 lift) & yella rockers.

I really can't tell much difference over stock noise...

 

Ok Arnel...if it's over 1 full turn...do I go longer or shorter on the push rods? If it's less than a full turn do I go with the 7.400 push rods?
I'm going to pull the valve cover off of the pass. side and do the check...
Thanks
Sleeper

 

I can live with that..I have a comp cam 224/224 .567 .567 lift lsa114

 

I called Napa auto parts and they don't carry the push rod checkers. I have a comp cam 224/224 .567/.567 lift on a LSA114. Patroit heads with 62cc from 64cc chambers, Patriot gold springs. Harland Sharp 1.7 rockers.
Next I'm going to do the push rod check without a push rod checker...
Thanks,
Sleeper

 

Dude... you have a cammed LSX... IT'S GOING TO SOUND LIKE THAT You make more threads on this than anyone. If you can't deal w/ the noise go get an '08 C6 w/ the LS3 and leave it stock. You'll have 390 rwhp and it'll be quiet.

If you want to do it right, get a pushrod length checker form thunder racing or comp cams and order the correct ones. Also, get some true roller rockers like the Yella Terra's I have.

 

I guess I'm using the wrong roller rockers (Harland Sharp) and the wrong every freaking thing because I understand the sewing machine sound is suppose to be there. BUT this sound isn't the way it's suppose to be...others even with larger cams are quieter...I did the push rod check by loosening and spinning a push rod then finger snug until the push rod was not spinning then torqued it to to GMs 22 ft lb and it took 2.25 turns to 22 ft lbs.
Now if you don't like my threads on this problem you don't have to reply to them..
thank you for your help in the past.

 

You have to get it were the rocker just touches the pushrod and the lifter with no play in it.You rock the rocker back and forth and turn the bolt down untill there's no play in the rocker,Then count the turns when you snug the rocker down,Not torqued yet.Did you read LS1 How to on this?...............Paul

 

No I'll go there..I saw in one of the post of my "MANY" someone said count the turns to 22 ft lbs..
Thanks Paul...
Deno

 

I think its just till it gets snug.I'll read it again myself ..........Paul

 

I just remembered you don't have Yella Terra Rockers.Once the rockers are sitting in the right place, use a 10mm socket and extension but NO SOCKET WRENCH, and finger tighten the rocker arm bolts until both of the bolts get too tough to spin with 2 fingers. You can take your index finger and try to spin the pushrod under the rocker arms as well, and it should have some friction on it and just barely spin, if spin at all. This is called "Zero Lash" and it is where there is no preload on the lifters....the lifter is touching the pushrod, the pushrod is touching the rocker, and the rocker is touching the valve, all without putting any pressure on the lifter.
NOW, get your socket wrench out and attach it to the 10mm socket+extension you were using. Without turning the bolt AT ALL, place the wrench in the 12 o'clock position. What we have to do is count the bolt turns until the instant the bolt gets hand tight. Turn each of the two bolts 90 degrees clockwise, then set the wrench at 12 o'clock and repeat (do each bolt one 1/4 turn, and keep alternating).....each 1/4 turn per bolt seems to equate about 10-12 thousandths preload (this is a very rough guess!).

If you get MORE than 1 full 360 degree turn on each bolt, remove the rockers and install the shims on the bottom of the pedestals and repeat this process to check the new preload. The shims seem to reduce the turns by approximately 270 degrees. You must install a shim on BOTH bolts, not just one or the other. If you got LESS than 1 full 360 degree turn then you are ok to leave the shims out!

Every car will be different so make sure you check this! You want the smallest number of turns you can get, as long as you have at least 1/4 or 1/2 full turn of preload in there once you are all setup. If you get to the point where the bolt is tight yet you can still spin the pushrod (without using shims), then your pushrods are either too short, your valves are too short, or you have some strange valvetrain geometry. You MUST have some preload or it will be OBSCENELY loud and run very poorly. Longer pushrods may fix your issue in this case.

 

Deno, EMPTY YOUR PMs!!! By what you are describing you need shorter pushrods. Probably 7.350. I used that exact length before. You dont need to count the turns til they're torqued, just from the point of no free play, to the point of the rocker being seated completely.
I explained a little better in the PM, but CANT SEND IT TO YOU. I'll send it later tonite.

 

Thats exactly right.......

 

You gotta hear the sound clip. It aint right!!! It should not sound like that. Even over the net with crappy speakers!!!!