jd_28ky

I recently rebuilt the engine in my 91 mustang gt. Im using trick flow cylinder heads, trick flow roller rockers, ford racing hydraulic roller lifters, and a comp cams XE270HR cam. Ive got a really loud ticking sound most noticible at higher rpms. This is the third time ive took my valve covers off and the rockers move by hand. Ive been setting them to zero lash then going about a half a turn. I noticed the 2nd time i adjusted them that by the time i rotated the engine around by hand the lifter i had just adjusted was loose again. are the lifters not holding up? should i try to adjust them again? ive got a set of used lifters from another engine and was thinking about trying them. Is it possible spring pressure is to high bleeding down the lifter? I would appreciate any help. thanks.

dreamer1uk

Did you prelooad the hydraulic lifters before you set the valve lash?

mjr46

they are loose after you set them because there is no hydraulic pressure present, once the motor fires up = issue solved, don't keep readjusting them because they are loose after motor is rolled over...........also I assume you set each cylinders rocker with the cam on the base circle for each rocker adjusted/set??....also , the tick noise may be a header gasket leak, search for such or post a vid of the noise, your ametuer interpretation of the noise may be incorrect.

jd_28ky

i set the intake valve just as the exhaust valve started to open, and set the exhaust valve just as the intake closed. I spun the pushrod by hand until i felt it dragging then went a half turn. I was unsure if the lifters held the pressure when the engine isnt running, the stock engine i removed has no slack in the rockers even after turning it by hand.

RyaNCSU1

Ive actually got the EXACT same problem. Ive readjusted them a couple times with the exception im only going 1/8 turn past 0 lash per recommendation from my machinist. Only get the ticking on the passenger side. Might check the header gasket just to eliminate that.