Valve Lash

[SloGN]

Guys

I'm having trouble keeping my rockers from clicking when hot. I set the lash @ 25k. My rockers are T&D on a set of TA alum heads. The way i adjusted them was make sure both valves are closed and tighen the allen stud down until i could fell the puch rod drag when spining it. I then went 1/2 turn more and lock the nut down. So i used the thread pitch meathod on a 1/2 turn should be 25k there abouts.


So my next question is can the Alum heads grow enough when hot to make the lash loosen up and cause the rockers to rattle,or did i not lash them enough.

The cam is a DLS unit and the roller lifters are morels.


Thanks for looking!

 

[LOT]

noise

I have TA aluminum heads and use the same procedure and 1/2 turn--no noise on mine. I have a Comp billet cam and Scorpion Hyd. roller lifters.

 

[pacecarta]

try doing it right
its not lash its preload but sounds like you got the .025 preload idea

loosen rocker and grab the pushrod , while you slowly tighten rocker rattle the pushrod up and down just until the pushrod no longer has play up and down thats your zero preload point
from there turn in 1/2 turn which would be .025 on the t+d
if you turned until the rod wont spin on a lifter that dosnt have oil in it you are mostlikely at the bottom of the lifter travel

if you had 885 race lifters only go 1/16 past zero (preload .002-.004)

the other thing is the t+ds can make noise

did you check the position of the rocker cup at the pushrod to be sure the prods are the correct length
T+ds are adjustable but only within a .100 window (1 turn up or down from cup flush on underside of rocker )
if you go too far up or down you can cut off the oil supply to the rocker

 

[LOT]

somewhat related

If a person wanted their hyd. to act more like a solid--would you increase or decrease preload?

 

[toomanymodz]

Decrease preload.

 

[SloGN]

try doing it right
its not lash its preload but sounds like you got the .025 preload idea

loosen rocker and grab the pushrod , while you slowly tighten rocker rattle the pushrod up and down just until the pushrod no longer has play up and down thats your zero preload point
from there turn in 1/2 turn which would be .025 on the t+d
if you turned until the rod wont spin on a lifter that dosnt have oil in it you are mostlikely at the bottom of the lifter travel

if you had 885 race lifters only go 1/16 past zero (preload .002-.004)

the other thing is the t+ds can make noise

did you check the position of the rocker cup at the pushrod to be sure the prods are the correct length
T+ds are adjustable but only within a .100 window (1 turn up or down from cup flush on underside of rocker )
if you go too far up or down you can cut off the oil supply to the rocker

Thanks


I meant to say preload and not lash lol. but anyhow i set the intial perload with the engine on a stand. The lifters had beeen run one time before so i know they had oil in them and also i primed the hell out of the engine to make sure i got oil out of all the rockers.

i didn't move the push rod up and down until no move way there. I only way i knew about was spin the pushrod till you get som drag when turning and then go to the set amount of preload.

The motor sounds great when cold but after it gets good and hot then it rattles just of idle. My oil pressure is about 35psi hot so i can't be a lack of pressure.

I'm gonna add another 1/4 turn to the adjuster and see how that sounds. That will put the preload in the area of 30-35k.

I'm thinking that the heads are gowing when they get heat soaked. I probaly should adjust them when hot i i don't care to make a mess!



Thanks guys