well i ran my truck and when i stand on it it the motor starts making a weird smacking noise and starts losing power. today i thought i would start by checking valve lash and found #7 cylinder exaust valve was lose as f^%$ so i rotated the engine till the valve was closed attemped to tighten it and it wont tighten the alum 1.6 rocker arm draws tight against the head where the stud goes into the head. am i wrong in thinking this is a bad lifter or you guys think bad cam.
I would guess bad lifter if there not soild lifters
i meant to put that in there its a .470 int and exaust howard hydralic cam but i am running 1.6 rockers to get more lift with my operating range i dont think its the cam with how loose it was but idk
could this be when i had my heads done last year i didnt know what cam i was gonna be running so the machine shop said he normally put 115# spring in for hyd cam 135# spring for sld so he put 125 in my heads and i had a sld cam last year and went with hyd this year. this cam and lifter set dont have but maybe 3hrs of run time
on that rocker is the stud stock or screw in stud? if stock is it pulling out of the head. over the motor over and watch the travel on the valve and see the same as the other valve. and the closed seat pressure is not the problem it would be the open pressure. i would check that that lube on the cam before any thing.
yes they are just press in i will look in to that im open to anything i guess. this thing was running great and all of a sudden this so the stud pulling makes sense. i was warned about it cause of running the 1.6 rocker.
the rockers have nothing to do with that. its lift of the cam and spring pressure and rpm, heat in the motor. a cheap way to keep it from doing that is drill though boss and stud and put roll pin in it.
If when you look at the stud it looks fine, I would pull intake off and pull that lifter and look at the bottom. Kinda sounds like that lobe on the cam is wipped out. I have seen this happen alot, and have had it happen to me. Did you break in the cam and lifters after it was put in?
i did break the cam in but the stud is fine its a howards cam i dont want to pull the intake but i guess im going to
My guess would be collapsed lifter, bent push rod and possible lob damage.. thats just my guess with out see'n it..
GotMud?
gonna change the lifter tomarrow and see what happens
What did you end up finding?
that is was way to hot to work on it i spectated for the day but ive talked to a couple engine builders and they both said that if i would of hurt the lobe the pushrod still would stay in lash and not have play. that i have a lifter that wont stay pumped up. not saying nothin bad but i have done some reading and it seems pretty common with howards cams good cams bad lifters im prolly just gonna put a new cam and lifters in it to be safe