delsold

iTrader: (7)

I took my valve covers off today in my lab so i could check and see if i couldnt find out anything on where that damn sewing machine noise i'm so adimitly trying to find. Anyway everything looked good except i noticed that every spring that was at zero lift had a substantial amount of lash. I could wiggle with my fingers and get quite a bit of movement. Are the ls1's supposed to have that much lash? I figured since it was a hydraulic cam they should have zero lash when they are at zero lift, and since the noise seems to get quieter when the oil gets hotter i thought maybe there shouldnt be that much lash. Anyone have any insight on this? I was thinking about going to a 7.425" pushrod and seeing if that makes up for the excessive lash i have.

Thule

i got the same cam, i use comp cam 7400 push rods, harland sharp roller rockers, patriot dual springs, my car sounded like a saweing machine for the first miles and seems to be shutting up now..

how many miles on it?

delsold

iTrader: (7)

about 3500 miles. I think you having roller rockers probably helped some. I also use comp cam 7400 pushrods, but when i checked the lash today it was what seemed to me excessive.

1QUIKWS6

iTrader: (61)

Any time you switch to a higher lift cam that requires the appropriate springs for .600 or .650 lift - you're gonna get the 'sewing machine' noise to some extent - there's no way around it.

The noise mainly comes from the fast ramps on the new design cams coupled with higher spring pressures to work with the cams that make the valves snap closed much harder than before.

What brand oil you use has some effect, after my cam/head install, (and the lash was perfect from Mike @ RapidMotorsports) I was using Mobil1 - noise was very evident. Since then I have tried Royal Purple (seemed to quiet down some), and now finally I am using Castrol GC 0W-30 (has quieted the noise substantially).

I also use the Morel lifters and HS rocker arms with Patriot Gold springs.

-Jay-

delsold

iTrader: (7)

i think this is where my problem lies. Im using stock rocker arms which are non adjustable, and seem to have too much lash. If i switched to an adjustable rocker, or a longer pushrod i believe the noise would quiet down some. Btw i use Mobil 1 0w40

1QUIKWS6

iTrader: (61)

The HS rockers I use are non-adjustable (i.e. adjustment comes from PR length just as stock). Installer must measure for correct PR length and use proper torque spec on rockers for correct lash.

Required pre-load also depends on what style/mfg lifters you have - they normally each have their own reccommendations.

Thule

in most cases 7400 is just rigth with the patriot cam, but iðve seen other though,

1QuikWS6, you got the same rockers as i do? 1.7 non adjustable saft mounted?

1QUIKWS6

iTrader: (61)

Those would be the ones. I really like them -even though they are said to be slightly heavier than some others available.

I would have gone with the Jesel's - but the cost is just redonculous...

Thule

i like them to, little rattling, and seem to be a qualaty product, but wasnðt your fitment a little tigth?

vettenuts

iTrader: (4)

When you say "loose" do you mean the rocker tip can be lifted so it ticks against the valve stem or do you mean they wiggle side to side? If side to side, that is normal. You should have got an adjustable pushrod and figured out your required pushrod length.

dmiz0420

iTrader: (8)

Did you upgrade to an ls6 or ported oil pump w/ the cam?

delsold

iTrader: (7)

it does slide side to side, but it can actually be lifted up (not a ton, but enough to get a few one thousandths feeler gage in there)

delsold

iTrader: (7)

ported ls6 pump. 45psi at hot idle 60 psi at cruise and 75ish psi at WOT